Autor Wątek: [NASA Gravity Assist] : Season 5  (Przeczytany 6763 razy)

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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #30 dnia: Czerwiec 11, 2023, 09:34 »
Rozmowa z ekspertka od pogody kosmicznej.
Głównym celem jej zespołu jest wspieranie obecności ludzi w kosmosie.
Dodatkowo jest dbanie o ochronę misji robotycznych.
Bez poznania pełnej natury CME trudno wyobrazić sobie dalsze podróże kosmiczne.

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Yaireska Collado-Vega: It does, for example, the solar energetic particles that we spoke about, those particles can cause instrumentation damage. And that doesn't mean only on Earth, it means in actually all the space. So when you have a event happening on the Sun that is towards a mission, you have to have those predictions so the mission can try to protect from the Sun's activity. So it actually affects every mission that we have out there.

Gravity Assist: Meet a Space Weather Scientist, with Yaireska Collado-Vega (1)
Oct 22, 2021


Yaireska Collado-Vega studies space weather at NASA’s Goddard Space Flight Center. Credits: NASA

Our Sun lights up the solar system, but it’s as not calm or predictable as it may seem. Flares and explosions called coronal mass ejections unleash fast-moving particles and radiation that pose dangers to spacecraft and astronauts alike. Yaireska Collado-Vega leads a team at NASA’s Goddard Spacecraft Center that is studying the solar weather environment so that robots and people exploring space can be protected. In this episode of Gravity Assist, she describes the excitement and challenges of understanding space weather, and how she got to be a NASA scientist.

Jim Green: When we look into space, it looks black and empty. But that turns out to be completely wrong. In space, huge, invisible storms can occur.

Yaireska Collado-Vega: You don't want a mission to be damaged by the Sun's activity. Because that would mean that you lose every single data that that mission can give you.

Jim Green: Hi, I'm Jim Green. And this is a new season of Gravity Assist. We're going to explore the inside workings of NASA in making these fabulous missions happen.

Jim Green: I'm here with Dr. Yaireska Collado-Vega and she is the director of the Moon to Mars Space Weather Analysis Office at the Goddard Space Flight Center. She is an expert in predicting space weather. Welcome, Yari, to Gravity Assist.

Yaireska Collado-Vega: Thank you so much for having me. Jim, I'm so glad to be here.

Jim Green: To start off, what exactly is space weather?

Yaireska Collado-Vega: Space weathers are the conditions in space that are mostly dominated by the Sun's activity. So the Sun is our star, right? That's why we have life on Earth. But the Sun can have solar storms that come in different types, like for example, coronal mass ejections, solar flares. And also this activity can actually accelerate particles to fractions of the speed of light. This kind of activity can cause what we call space weather effects that here on Earth can actually include problems with communications, GPS signal loss, and in the most dangerous types, it can actually cause power grid disruptions.

Yaireska Collado-Vega: Now, when we talk about humans in space, those energetic particles that are accelerated to fractions of the speed of light can cause a hazardous environment to the astronauts. And those particles also can cause problems to the instrumentation of the satellites in space. So it can actually damage our technology, the technologies that we use every day.

Jim Green: Well, you know, the Sun is really pretty far away. And so as you say, it goes through a variety of changes, creating really enormous changes in the wind that it produces. And, and so these events propagate from the Sun outward into our solar system. And so how long does it take for those kinds of events to hit the Earth?

Yaireska Collado-Vega: It depends on each event. Each event has a different timeline. For example, if you talk about solar flare, when we see a solar flare, this signal here on Earth is already here. It travels to the speed of light, it’s eight minutes, that's all it takes. So flares are something that is very difficult to predict. So we do have some models that try to do predictions of solar flares. Now when we talk about coronal mass ejections, that's different, because we're talking about big explosions of particles coming from the solar corona. And depending on the speed, they take about two to four days to arrive to Earth. And then if you talk about solar energetic particles, now we're talking about fractions of the speed of light, so you can have an event arriving on Earth in half an hour, or in hours.

Jim Green: Wow. So how hard is it to predict when these flares and coronal mass ejections occur?

Yaireska Collado-Vega: It is it is difficult. We use a lot of models. We use different observatories. For example, we use the Solar Dynamical Observatory to look at the Sun's Earth-facing disk in different wavelengths. So you're actually looking at the Sun in different temperatures, different layers, so you can see more what is happening in in the solar corona.

Yaireska Collado-Vega: Now, to see a coronal mass ejection though, you need a coronagraph, which is an artificial eclipse. You're actually blocking the Sun to be able to see what's coming out of it. So it's not an easy way to predict this kind of events. And we don't have that many observatories as we would like to have. And then when we see the coronal mass ejections from the coronagraph, we have tools that we use to analyze and have measurements of those coronal mass ejections.

Yaireska Collado-Vega: For example, speed, width, direction, and those are the measurements that we put in into the simulations that could give us a prediction on when and where those coronal mass ejections are going to impact. Now SEPs, there are different models that can actually try to do predictions of SEPs, solar energetic particles. And these are actually trying to understand when the event is going to happen, the intensity of the event, and the duration of the events. And it's not easy, and we need more data sets to actually be able to improve this kind of models.

Jim Green: Well, it sounds like you do a lot of computer work with a lot of models that are going on. But once these events leave the Sun, do they change as they propagate out into the solar wind and through the solar system?

Yaireska Collado-Vega: They do. In terms of solar flares, you know, it depends on the direction of where you are. It’s an abrupt eruption of radiation, right? So depends on where you are. If you're here on Earth, whether your observer is, it depends on where you are whether you actually will get more affected. Now when you talk about coronal mass ejections, you know, depending on the eruption, per se, that's what you will have erupting. And some eruptions accelerate, some decelerate, some actually rotate. So it's a very unpredictable environment. And it's actually really fun to do. And it's something that I actually tell my team all the time, like, this is something that is fairly new in the field of physics, right?

Yaireska Collado-Vega: This is something that we just started to do, starting in the 1950s, let's just say. And then when we analyze these things, we comprehend how dynamic the Sun can be, and how many effects it could have in the different technology and the instrumentation that we use. So my team, the main goal is to support human exploration activities. But we also have a secondary goal that we protect NASA missions. It doesn't matter where a coronal mass ejection is going, we analyze it, and we make sure that we have those predictions. And we can send those prediction to the NASA missions, so they can protect themselves from the activity.

Jim Green: Well, what typically happens then when a CME, this coronal mass ejection, hits the Earth or the Earth's magnetosphere?

Yaireska Collado-Vega: When the CME actually arrives at Earth, then it will actually create what we call like a punch. It will actually punch the Earth magnetic field and that actually causes while we call a geomagnetic storm. There's different things that you have to take into consideration when you talk about the effects depending on the velocity of the coronal mass ejection and depending on the direction if it hits face on or if it's actually a glancing blow all, or, you know, the magnetic field inside the coronal mass ejection is also really, really important because if you have a magnetic field inside the CME that is actually southward, which means that’s pointing down, that means that you're going to have a higher probability to have a higher geomagnetic storm because you will have what we call magnetic reconnection. And it's actually a transfer of energy that happens from that magnetic field to the particles.

Yaireska Collado-Vega: When you have higher geomagnetic storms, that's when you get really, really nice auroras, and I love auroras. I haven't seen one in person though. When you have the auroras, they're amazing. I call them the rainbows of space weather. But when auroras happen, that means that you have a high activity happening on the magnetic field of the Earth caused by the Sun. And this will mostly be caused by that CME arriving and causing that geomagnetic storm.

Jim Green: Right. Every time the magnetosphere gets hit with a coronal mass ejection, we're going to have aurorae. Really fantastic. Well, what kind of instruments do we need to really monitor space weather, and where do we put them in space?

Yaireska Collado-Vega: We need different types of instruments. For example, we need imagers that will actually be able to see the Sun in different wavelengths, UV for example, and then we also need coronagraphs that will actually let us see the coronal mass ejections being ejected from the solar corona. Not only that, we also need magnetograms, we need to understand how the magnetic field the Sun changes, because depending on how that magnetic field changes, and evolves, that's how you have to have the activity happen. So we need different observatories. And we use right now the Solar Dynamics Observatory, we use the STEREO mission, we use SOHO, which is more than 25 years old, and we still use it.

Jim Green: So why is space weather so important to know relative to the other spacecraft that are orbiting the Earth or tracking out into the solar system, going to places? Does space weather affect these missions?

Yaireska Collado-Vega: It does, for example, the solar energetic particles that we spoke about, those particles can cause instrumentation damage. And that doesn't mean only on Earth, it means in actually all the space. So when you have a event happening on the Sun that is towards a mission, you have to have those predictions so the mission can try to protect from the Sun's activity. So it actually affects every mission that we have out there. And we have to be able to predict it because you don't want a mission to be damaged by the Sun's activity. Because that would mean that you lose every single data that that mission can give you. So as a NASA entity, my team is, you know, trying to protect those NASA missions across the whole solar system.

Jim Green: Well, you know, as humans, leave lower Earth orbit, go to the moon and live and work on a planetary surface, then we're going on to Mars, should astronauts be concerned about space whether?

Yaireska Collado-Vega: The same solar energetic particles, those are the one that created the high radiation environment that could be hazardous to the astronauts. So right now, for example, we have astronauts in the International Space Station. The International Space Station is nside the magnetic field of the Earth, so that means that they have that shield. But now when we talk about getting those humans out of that shield, now we have to take into consideration that they're going to be exposed to a higher radiation dosage. So now we have to be able to predict better those solar energetic particle events, so we can actually communicate that to the astronauts so they can get protected from those events.

Yaireska Collado-Vega: And we, our team are working really close with the Johnson Space Center space radiation analysis group, to be able for us to communicate what the SEP models predict, so they can actually communicate that to the astronauts. It's a very intense work. (laughs) There's a lot of stress. (laughs) But it's something that is really exciting because you're protecting those astronauts out in space. And it will actually help us go further than the Moon later on in the future, going to Mars, because we're preparing now to go to the Moon, but eventually we will also calibrate all these models to be able to predict that kind of event at Mars.

Jim Green: Well, indeed from SOHO as you say, we can see these CMEs coming. When we see them, what can we do?

Yaireska Collado-Vega: So in terms of my team, we actually send the analysis to the missions, and they decide what to do. But in terms of what they can do, they can actually try to not face the storm. They can maneuver the spacecraft not to face the storm, or they can put instrumentation in safe mode. The last thing that you would like or want to do is to turn anything off, because when you do that, you never know if it's going to be turned on again.

Yaireska Collado-Vega: Now, when we talk about astronauts, then we're talking about shielding. There's a lot of research now that is going to how the astronauts going to be shielded from these events if they happen. And not only that, it's not only the shielding, but the communication to when the events are going to happen. There should be a type of autonomous way that the astronauts could actually see the events and understand what is happening if, for example, they’re on the surface of Mars. So those things are things that we're still working on.

Jim Green: Well, have you been working with the Perseverance rover team and the Ingenuity helicopter on Mars, and is space weather of interest to those teams?

Yaireska Collado-Vega: We don't work directly with the Perseverance and Ingenuity teams. However, every time there’s a Mars-directed event, we do talk to the teams. And we had an incident, for example, that happened, not so long ago, that we had a flare that happened close to the time that they were going to have the Ingenuity’s first flight. And that event actually caused a coronal mass ejection that was predicted to arrive the day of the second flight. We communicated with the team, with Ingenuity team, to make sure that we could analyze the event to make sure that the event wasn't going to cause a higher radiation environment that could actually cause problems to the Ingenuity instruments.

Yaireska Collado-Vega: And it was, it was, it was stressful, you know, it was communication back and forth, and making sure that we could analyze the event completely. And one of the main things that we had to do is, you know, you have the event traveling, so we looked at other places that the event was going to arrive to see what was the environment in that place. And that happened with Solar Orbiter. So we looked also at the Solar Orbiter data to see what exactly was the environment caused by the CME impact, and then we could actually say, okay, there's nothing going to happen, you're gonna be okay. But that shows you that we need to get this asset protected from this event. And sometimes, you know, it's not realized until it happens, but you know, my team work really hard on that.
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #31 dnia: Czerwiec 11, 2023, 09:34 »
Gravity Assist: Meet a Space Weather Scientist, with Yaireska Collado-Vega (2)


Yaireska Collado-Vega grew up in Puerto Rico and knew she wanted to work at NASA when she was 6 years old. Credits: NASA

Jim Green: How far out into the solar system can we really monitor space weather today?

Yaireska Collado-Vega: In my team, for example, we do monitor anything that goes towards the orbit of Jupiter. After that, there's many limitations, many physical factors that you take into consideration that the model cannot actually predict very well. You can have an idea of what it’s going towards after that. But to take it, you need to take it as a grain of salt, because there's a lot of limitations there in the models that could actually affect the result that you're getting. But in terms of you know, until the orbit of Jupiter, we're pretty good.

Jim Green: You know, with all our missions in space and making observations of the Sun and the solar wind, are there questions, or at least one thing in particular, you would really like to know about, that we haven't uncovered the answer yet?

Yaireska Collado-Vega: One of the things that we really don't know exactly how it happens is the acceleration of those solar energetic particles. And that's something that we're trying right now to understand with the new missions that we sent out to space, for example, Parker Solar Probe and Solar Orbiter. Those are one of the key scientific questions that they're trying to answer. And for us, it's really important to understand how these particles get accelerated, because those are the particles that cause hazardous environments to astronauts, those are the particles that we're trying to predict, to protect them. You know, more information that we can get with what happens with those particles, how they can get accelerated at fraction, so the speed of light, where they actually travel, how they travel with the magnetic field lines, all that kind of information is vital for those models to do better predictions, so we can communicate that to the astronauts.

Jim Green: Well, what's a typical day like for you when you go to work at NASA Goddard Space Flight Center?

Yaireska Collado-Vega: A typical day well, during the pandemic, it hasn't been typical. But we, in terms of my team, we do, the first thing that we do is look at the Sun, look at the activity, what's going on. We also look at what happened the day before, so we can actually see if there's anything that we need to expect. We also understand and analyze what's going on and the predictions of the models. We actually also try to see if we can actually understand that there are any outages in the model, sometimes it happens you have some data outages, that actually would create a domino effect. And then the model will not have a prediction. And then we do have tag ups. We'd have a tag up with our team where we explain the whole space weather environment, if there were any CMEs, were there any flares, if we're expecting anything, if we have geomagnetic storms, all that kind of nice stuff. And then later on we do have a specialized tag up with the space radiation analysis group where we actually only discuss the radiation environment. So now we're talking about solar energetic particle events and how the models are predicting, what's going on and the CMEs that are related to that kind of activity. So it's a pretty busy environment.

Yaireska Collado-Vega: When you are doing your real time forecasting and analysis and you have something happening for example, I don't know, you have to go get your kid from school which happens, you have to make sure that you have a backup because the Sun is not going to wait. Actually what you do is you prepare your analysis, you send it to your secondary person, and that person takes over for the time that you're not going to be in charge. So it's a different pace than research. Research, you're used to be calm, relaxed, and you know, sometimes, waiting you know. It's coding and reading. Here is very fast paced and you cannot leave the computer. And if you do you have to make sure there's somebody else watching.

Jim Green: Well, Yari, I always like to ask my guests to tell me what was that event, person, place, or thing that got them so excited about being the scientist they are today? And I call that event a gravity assist. So Yari, what was your gravity assist?

Yaireska Collado-Vega: I was always interested in science but my my parents, I come from a very humble, you know, home in Puerto Rico. They decided to do a trip to Orlando for my sister’s quinceañera and everybody's very excited. We're gonna go to Disney World. Yeah! But because they knew I was very excited. about science, they took me to Kennedy Space Center. And I'm not gonna lie, that was the first time that I said, I want to work for NASA. I want to do this for the future. And I was six years old. And people laughed at me every time I said that I wanted to work for NASA, because you know, a little girl from an island, you know, working for NASA something that at that time, you didn't realize it, you didn't think it was possible, but every time I somebody laughed at me, I would be like, “I'm gonna do this, and I'm gonna show you that I can do this.”

Yaireska Collado-Vega: When I went to high school, you know, things got a little diffused. I actually thought about going into tourism, and then I thought about going to law school. But then I had a really nice teacher that said, “No, your thing is physics. But then, you know, everybody that I said, I wanted to go through physics, people were like, “Oh, no, don't go through physics, as a scientist, you're not going to earn any money.” And I was like, “I want to do this, not because of the money, because this is what I love.”

Yaireska Collado-Vega  And I actually went to University of Puerto Rico, Mayagüez, and I did my physics undergrad. But the key element that got me to this specific field was when I got an internship. I actually was not accepted that the first time. The second time was the time that I got accepted. I always tried, I was like, I'm never gonna, I'm never gonna quit doing this out. always gonna try. And the second time, I got accepted. And that's when my mentor sat down with me and explained me what space weather was. And for me, it was like, I was mind-blown. I had no idea that it's the Sun could cause so many effects. And you know, I heard about auroras before, but I had no idea exactly what was happening behind the curtains, like we say, and I fell in love of the field. I said, “Wow, this is a fairly new field and physics. There's a lot of new things that we need to know. There's a lot of uncertainties. This is where I want to be. This is where I want to stay.” And that's, that's what happened and here I am.

Jim Green: Yari, you've had such a fantastic experience getting involved in space weather in space science. What advice would you give those students that would love to follow in your footsteps?

Yaireska Collado-Vega: I guess I would tell them to never stop being themselves. I had many instances that people will tell me, “Well, you don’t look like a scientist.” And if I left that common, get into me, that will have been really, really damaging to my career. But it's difficult to stay yourself when you're surrounded by, you know, so many different people. And it happens, you know, you have good experiences, you have bad experiences. But I think you always need to stay true to yourself.

Yaireska Collado-Vega: And not only that. Network, talk to people, don't be afraid. Every scientist is a normal person. I remember when I was starting at NASA, and I will be, like, afraid of talking to people. And then, you know, I went out with my mentor. And I realized that she had a family that she had two daughters, two amazing daughters. And that, you know, she was just a normal person. I was like, “Oh, wow.”  And that's when my connection to my mentor actually grew. Because I understood that I could actually be human with her.

Yaireska Collado-Vega: And I think that's something that I tell all my students: Never forget to be yourself. And also never forget that everybody here is human. Everybody here had a career, everybody here had obstacles, and everybody could be actually a mentor to you. So take advantage of that. And don't forget to do internships, they're amazing. And they will show you know how the environment works outside of academia. It’s not the same to go to school, to go to college, as to go to work. It’s not the same. And do an internship will show you that even before you graduate. And that will give you an idea of what you want to do for your future.

Jim Green: Thanks so much for joining me and discussing our wonderful space weather activities that we do here at NASA and your fascinating career.

Yaireska Collado-Vega: Thank you, Jim. Thank you for having me. And I hope this encourages you know, early career people you know, those kids to be involved with the space weather field because we have a lot going on. Not only space weather, heliophysics, you know, it's a big field and it's an amazing thing. And there's a lot of uncertainties that we still need to discover. So, we have a lot of work to do.

Jim Green: We do indeed and I'm delighted you're involved in it.

Yaireska Collado-Vega: Thank you so much.

Jim Green: Join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I'm Jim Green and this is your Gravity Assist.
 

Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Oct 22, 2021
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-meet-a-space-weather-scientist-with-yaireska-collado-vega
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #32 dnia: Czerwiec 18, 2023, 11:44 »
Gravity Assist: Solar Power for the Moon, with Lyndsey McMillon-Brown
Oct 29, 2021


Lyndsey McMillon-Brown at NASA’s Glenn Research Center is developing a new type of solar cell that uses innovative materials and offers many advantages over the current state-of-the-art-technology. Credits: NASA/Bridget Caswell

As NASA prepares to send astronauts to the Moon through the Artemis program, engineers are working on technologies that will give these explorers power – solar power, that is. In space, the harsh radiation and huge temperature changes make for a challenging environment. Lyndsey McMillon-Brown at NASA’s Glenn Research Center leads a study of solar cells made from a material called perovskite. This material has the potential to help power lunar habitats one day. Learn about this innovation and Lyndsey’s journey to NASA.

Jim Green: We get energy here on Earth in many different ways, such as using the Sun with solar cells. But we use them in space also.

Lyndsey McMillon-Brown: You go from, very hot to very cold, very often in space. So we're looking at how do we protect these materials? And how do we design them to be robust?

Jim Green: Hi, I'm Jim Green. And this is a new season of Gravity Assist. We're going to explore the inside workings of NASA in making these fabulous missions happen.

Jim Green: I'm here with Lyndsey McMillon-Brown and she is a research scientist and engineer at NASA Glenn Research Center in Cleveland, Ohio. Lyndsey is the principal investigator for a project that is working on solar cells for space applications, including the Moon and Mars. Welcome, Lyndsey, to Gravity Assist.

Lyndsey McMillon-Brown: Hello, and thank you for having me. I am so excited to be here with you.

Jim Green: Well, how did you get started working with NASA?

Lyndsey McMillon-Brown: It was really fortunate, you know. When I was younger, actually, I went to space camp. So I always want to mention that first.

Jim Green: Cool, mhm.

Lyndsey McMillon-Brown: I was in fourth grade, and went on a Space Camp trip. And like everyone, I feel like, you can't go there without being amazed and really intrigued by the work. But then fast forward a few years, when I was in college, I was really interested in working at NASA again. And since that love for science stuck with me, you know, over all those years since Space Camp, I was an engineering undergrad. So I applied for an internship. And for me, the access to NASA wasn't super difficult because NASA Glenn is in Cleveland, and I grew up outside of the Cleveland area. So I was pretty familiar with knowing there was a NASA center close to home.

Jim Green: Well, that's really great. So that internship program is called a co-op program. So what did you do as a co-op?

Lyndsey McMillon-Brown: Yeah, I had a great time as a co-op. And I feel like it really allowed me to find and center myself as an engineer, and then discover research and realize that I wanted to pursue that as a career. So as a co-op, I had this opportunity to do work in school rotations. And on each rotation, maybe I would be, you know, at NASA for about eight to 10 weeks.

Lyndsey McMillon-Brown So one thing I was able to do was work on transparent solar cells for adaptive windows. For example, if you think of smart windows for your home that would tint dark to prevent the Sun from coming in and heating your home. And we wanted those to be powered by solar. So we were working on: Is there a thin coating you could develop that could be on your window, but not disruptive to the light that you're getting in your home? So I worked on that for a while. And that was my introduction to solar cells. And I found the work to be really intriguing and exciting.

Lyndsey McMillon-Brown: Another project I got the opportunity to work on during a different rotation was a Mars hopper. We were looking at carbon sequestration. So, can you have a hopper that sits on the surface of Mars, absorbs the CO2, and then basically splits it and harvests energy from, you know, the resulting water or oxygen. And I was really thrilled to know that in my tinkering in the lab, I was helping this mission that we've had in our minds to go to Mars, you know, and sustain life for a long time. So I really enjoyed that work, too.

Jim Green: Well, then you became a regular employee at Glenn Research Center, and steeped into solar systems and solar cell technologies. And I heard you'd written a paper about what happened on Mars with Opportunity’s solar panels. Can you tell us about it?

Lyndsey McMillon-Brown: Yes, I was so excited about that work. So with that one, we took a look at standard, state of the art solar cells that are triple junction solar cells. So they're, if you think of like a sandwich, they have many different layers, three layers, triple junction, and each layer is responsible for optimizing a certain part of the solar spectrum. And one of the challenges with those cells is sometimes they can be brittle, because they're crystalline. So they are sometimes susceptible to breaking or cracking.

Lyndsey McMillon-Brown: And we set up an experiment in our lab that would expose these solar cells to Mars dust storm conditions. So we varied the angle that the solar cells were placed at and we had this oncoming high speed wind blowing Martian simulated dust, since we don't have real Mars dust in hand yet in the labs. And this was really fun. I was working in the sandblaster box so I was able to get dirty. You know, I would come out kind of dusted with this, you know, red dust, and I got a kick out of that.

Lyndsey McMillon-Brown: But we were also really able to accurately model and simulate how these solar cells perform on Mars. And we checked that our in-lab simulation was accurate by using Opportunity rover data that we had courtesy from JPL.

Lyndsey McMillon-Brown: The Opportunity rover had a really long life and great exploration, and it provided us with lots of data. But ultimately, it stopped operating because a lot of dust accumulated on it solar cells, and it didn't have enough power to operate anymore.

Lyndsey McMillon-Brown  And we were able to compare our simulations to the actual solar cell performance on Opportunity. And that was such a rewarding experience.

Jim Green: So how did they turn out in that comparison?

Lyndsey McMillon-Brown: Yeah, they turned out really interesting. So a couple of the things that we learned was that when these solar cells are exposed to dust, of course, the dust will accumulate on the cell, and then less light will get through the coating of dust. Think of a dirty windshield, you know, in your car, you're getting less light as the driver. But another thing that happened, we would then clean off the cells, blow them with air to clean off the dust.

Lyndsey McMillon-Brown: So we figured the solar cells would then return back to normal. But actually, we don't fully understand what, but something electrical changes inside those solar cells as a result to the exposure to dust. So even the cells that looked fine, there's no cracks or damage to them. Their open circuit voltage decreased a bit. So the efficiency that the electrons move around in the solar cell changes when it's exposed to those dust storms.

Jim Green: Wow. Okay.

Lyndsey McMillon-Brown: Yeah.

Jim Green: So there's other types of solar cell technology, then that we need to use on Mars to maintain that high efficiency once you blow the dust off.

Lyndsey McMillon-Brown: Right!

Jim Green: Since dust seems to be a concern on Mars, are we still going to need solar panels on future experiments?

Lyndsey McMillon-Brown: I think we will. Dust is a concern. But through this investigation, we found ways that you can mitigate it. For example, if you place your solar cells between a 45 to 60 degree angle, that's really helpful for the dust to roll off. And we're also learning other things about coatings that will help keep the dust off of the solar cells and prolong the lifetimes.

Jim Green: Well, you're also working on solar cells for future lunar missions.

Lyndsey McMillon-Brown: Yes.

Jim Green: Are they the same as what you would use on Mars or not?

Lyndsey McMillon-Brown: So that's what we're looking at, we think they could be the same, we could continue to use these triple junction, you know, state of the art solar cells. But the Moon affords us another opportunity that we might be able to use lower cost solar cells, which is what I'm studying right now. And those are called perovskites. And perovskites are like plastic solar cells, more or less. So they're made from a solution. And since they're thin, that allows them to be deposited on different types of substrates. So they can be flexible, and lightweight. And they have a lot more versatility than these more rigid triple junction crystal solar cells that we've been talking about earlier. And the Moon affords us this opportunity, because there's a lot of real estate on the Moon. So we can really spread out and have a very large solar farm, if you would imagine, of these thin and flexible arrays and that would significantly drop the cost of production, manufacturing, and it drops the cost potentially, of launch. How do you get it up to the Moon?

Lyndsey McMillon-Brown: So the way I envision this is: You're gonna have different kind of habitats, almost like different houses. And you will have these large solar farms like an array that you might see when you're driving down the highway now. So we'll have this large area, many different panels all lined in a row, we're going to have to find the best angle to set them at or perhaps they track the Sun, so that they're always illuminated, appropriately without shadow.

Jim Green: Well, what's really exciting about going to the Moon and the Artemis program is we're going to the South Pole. And on the South Pole, there are places where there's eternal darkness, we call those permanently shadowed craters. But at the higher altitudes, at the crater rims, there are places of eternal light, and they see the Sun all the time. Perfect place to be able to put these type of solar panels. Are discussions going on at Glenn about using those places on the Moon of eternal light?

Lyndsey McMillon-Brown: Absolutely those you know, as a solar cell engineer, that's where you'd like to find me. So we definitely want to follow the light. But we work very closely with the battery people, power storage, management and distribution, because I'm one piece of a larger puzzle that has to work together and make sure you know if I can absorb it, and collect it, can you store it? Can you get it where it needs to go? Because we're also very interested in exploring some of those dark and permanently shadowed regions.

Jim Green: Yeah, the ability to then acquire that but then beam that energy somewhere that you need it down to a habitat or some other location, that's going to be real important. Well, do special materials like that suffer in space?

Lyndsey McMillon-Brown: They do. And that happens with any material you know, we have yet to find the “holy grail” perfect material that's impervious to space. Especially because space is particularly harsh. So for the perovskites that I'm looking at right now, they do a fairly good job at dealing with the radiation in space. And we call that radiation tolerance. So they have a high radiation tolerance. Now to study that, we've been sending some samples up to fly on the International Space Station.

Lyndsey McMillon-Brown: I'm largely involved with Materials in the International Space Station Experiment, which we call MISSE. And MISSE is this great opportunity for us to send up samples aboard the ISS. And our samples are placed outside of the International Space Station on the wing, and they're exposed to low-Earth orbit for six months, then the best part is those samples are really collected and returned to us. And we're able to analyze them and see exactly what changes they underwent when they were exposed to low-Earth orbit. So specifically, I've been able to send up these perovskite thin film samples. And we're interested in seeing how do they perform and how durable are they when they're exposed to all of the, you know, all the intricacies of space at once. That's the thermal cycling, that's being in vacuum, that's having radiation, and that's being illuminated by the Sun. And these are things that on the ground, we can test one by one in our different experimental chambers. But it's so valuable to be able to test it all at once in the true environment.

Lyndsey McMillon-Brown: And they do a better job than some of the existing technology. But we still do see some damage even when exposed to some higher energy particles. So we're concerned about that. And another challenge is the temperature cycling because you go from very hot to very cold, very often in space. So we're looking at how do we protect these materials? And how do we design them to be robust to thermal cycling?

Jim Green: Perovskite sounds really bizarre and exotic, but what is it and how is it made? What are its elements?

Lyndsey McMillon-Brown: Yeah, so perovskites for solar cells actually get that name, because the solar cells take on the same crystalline structure that the natural occurring perovskite mineral has.

Lyndsey McMillon-Brown: We generate our perovskites in the lab by combining various chemicals in a solution and when those chemicals come together, they arrange themselves in this order. And that results in a perovskite thin film.

Jim Green: Well, you know, I heard him about a method of making these called electrospraying.

Lyndsey McMillon-Brown: Yes.

Jim Green: What is that all about?

Lyndsey McMillon-Brown: Yeah, so electrospraying, that work is led by our collaborators at U.C. Merced. And electrospraying is really cool because it uses electricity to disperse a liquid into like a fine aerosol, like a cone of spray. And that cone of your dispersed material allows you to coat your substrate evenly. And once that, that liquid aerosol arrives to your substrate, we've noticed that the particles merge together, and they coalesce, and they make a really nice organized crystalline film without us having to do anything, and we call that self-assembly. So we really like the concept of electrospray. Because this can allow us to more quickly manufacture these solar cells. If you imagine like an assembly line, you have this substrate moving through, and it gets coated by the spray, and it just keeps on going for future processing down the line.

Jim Green: So it sounds like electrospraying is just like spraying on paint?

Lyndsey McMillon-Brown  Exactly. It's just like spray paint.

Jim Green: So it sounds like there's still so many different techniques that you need to investigate to really be able to create the right solar panels. And it's different between solar panels on spacecraft or those on Mars or the Moon. What do you think the future of solar cell research is all about? Can we make them more efficient and smaller? Or, or is it going in a different direction?

Lyndsey McMillon-Brown: Yeah, I think the future is bright, pun intended. But I think that we have so many opportunities. And what I would love to see is us designing unique solar cells for specific applications. I think some are really good. They have a high power density. So you only need a few solar cells to get a lot of power. Maybe we want to use those on smaller satellites or things like that, then if you open up and you’re on the Moon, maybe you want to have this large, cheap, but flexible array. So I would love to see us tailor-making solar cells or have you know, a Rolodex, so to speak of: these are the four solar cells that go best for these different types of missions.

Jim Green: So Lyndsey, what's a typical day like for you when you go to work?

Lyndsey McMillon-Brown: So a typical day is pretty diverse. And I love that. So I will collect some data and work in the lab and maybe make some thin film samples by spin coating. Then I will take those samples and I will measure them. I'll expose them to some light and see how well do they perform. Then I also have to analyze the data. So, in the afternoons, I'll typically sit down and have a lot of data in front of me. I'll make some graphs. I'll compare some things and get a plan. And then at least once a week I meet with my team, and we discuss other experiments that we're interested in and we devise a plan so that we’re always kind of moving forward in the right direction.

Jim Green: So Lyndsey, what is the next step in your research?

Lyndsey McMillon-Brown: So to date in our research, we've been looking at the different layers of a perovskite solar cell, and we've been working to improve them so that they can be durable in space. And now it's the time for us to combine them all and really work on the solar cell as a whole. And we're going to be looking at exactly how we might be manufacturing this solar cell for space.

Jim Green: Well, you know, you have a bachelor's degree at Miami University in mechanical and manufacturing engineering and a Master's and PhD at Yale in chemical engineering. But I also noticed that you really Recently, were named as a notable alumni from the Miami University College of Engineering and Computing. How does that make you feel?

Lyndsey McMillon-Brown: I was elated when I found that out. I was so proud and honored and shocked. That list of notable alums is not very long. And I was so thrilled that my alma mater, you know, thinks that I'm deserving to be on that list. So it makes me so happy. I love Miami University, and I've remained engaged with them. But that was definitely one of the brightest moments in my career so far.

Jim Green: Lyndsey, what is your advice to the young people out there that would love to have an engineering career at NASA?

Lyndsey McMillon-Brown: I would give the advice to have fun and learn something new. But don't be too hard on yourself. To be a NASA scientist, you don't have to have perfect grades. We have our weaknesses, too. But view your weaknesses as an opportunity to improve and learn more.

Jim Green: Yeah, that's fantastic. Well, Lyndsey, I always like to ask my guests to tell me what was that event, person, place, or thing that got them so excited about being the engineer they are today. And I call that a gravity assist. So Lyndsey, what was your gravity assist?

Lyndsey McMillon-Brown: My gravity assist was my village. You always hear, you know, “it takes a village to raise a child.” And I feel like there's so many great people, my parents, my husband, a great professor I had in college, Dr. Osama Ettouney. And they all rallied around me and encouraged me and inspired me, and gave me the tools that I needed and helped me build that skill set to be the scientists that I am today.

Jim Green: Well, that's fantastic. Lyndsey, thanks so much for joining me in discussing your career. It's bright. It's all about solar cells.

Lyndsey McMillon-Brown: Thank you so much for having me. This was so fun.

Jim Green: You're very welcome. Well, join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-solar-power-for-the-moon-with-lyndsey-mcmillon-brown
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Prawdziwy rezerwuar obcych światów w bliskim zasięgu  ;)
Więcej rozważań o układzie Dimorphos - Didymos przed poddaniem go dynamicznemu działaniu.


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Nancy Chabot: What's amazing about Antarctica is you'd be down there for six weeks, and an average field season finds between 100 and over 1000 meteorites during that period of time, just in those few weeks. Depending on where you are, you could find 100 a day, sometimes. They're just sitting there collected by these natural ice movements waiting, you know, sort of, for us to find them and then share them with the world so we can uncover all their secrets. I don't know it's hard to pick favorites among meteorites, I have my own personal ones, I personally worked on iron meteorites a lot. And pallasites are closely related, which are made of olivine and metal intermixed together.

Gravity Assist: How to Move an Asteroid, with Nancy Chabot (1)
Nov 19, 2021


Planetary scientist Nancy Chabot has been to Antarctica five times to look for meteorites. Credits: Antarctic Search for Meteorites Program/Nancy Chabot

A spacecraft is about to begin its journey to crash into an asteroid on purpose. NASA’s Double Asteroid Redirection Test Mission, or DART, will deliberately impact a small asteroid called Dimorphos to deflect its orbit around a bigger object, Didymos. While this system presents no danger to Earth, an asteroid the size of Dimorphos would cause regional devastation if it hit our planet. DART will demonstrate a potential method of protecting Earth from hazards in the future. Nancy Chabot, planetary scientist at the Johns Hopkins University Applied Physics Laboratory, has the details. She also discusses searching for meteorites in Antarctica and discovering the secrets of planet Mercury.

Jim Green: NASA has a mission called DART that will help us understand how to defend the planet against incoming Near-Earth Objects.

Nancy Chabot: It’s purposely going to crash a spacecraft into an asteroid to move it a little bit. And this is the sort of thing that you might want to do if there was an asteroid in the future that was headed towards the Earth and you wanted to move it a little bit so it wouldn't hit the Earth.

Jim Green: Hi, I'm Jim Green. And this is Gravity Assist. We're going to explore the inside workings of NASA in making these fabulous missions happen.

Jim Green: I'm here with Dr. Nancy Chabot. And she is the planetary chief scientist at the Johns Hopkins University Applied Physics Laboratory. Nancy, you also have an asteroid named after you, asteroid 6899 Nancy Chabot. Nancy, welcome to Gravity Assist.

Nancy Chabot: Thanks. I'm so happy to be here.

Jim Green: Well, you have been so active in researching what we typically call small bodies of the solar system, such as meteorites on up to even bigger small bodies. That material really comes together and over time builds up planets and larger objects. How did you get involved in that field?

Nancy Chabot: I actually didn't even knew this field existed until I went to grad school. I was an undergrad in physics, because I wanted to go into space science. And I thought, rhis is what you needed to do to go to into astronomy actually didn't even realize that, like planetary science was a thing that you could do with your life. And then even when I went to planetary science school, I sort of thought more about like missions and that kind of stuff. And it wasn't until, you know, somebody introduced me to meteorites, and then all of a sudden, it was like, wow, these aren't just things that we can look at, we can actually hold them in our hands. So rocks from space that you can actually hold in your hand and bring into the lab and inspect on a fine scale that you can't possibly do otherwise. So, I think that just really was an aha moment for me that it's like you could study space, but you can do it here and get your hands on it too.

Jim Green: Well, where do meteorites come from? And why are they so interesting?

Nancy Chabot: Well, mostly, meteorites come from asteroids, which is fascinating in itself. Though I'll just say, you know, quickly that we do have a few from the Moon. And there are only samples from Mars currently, that we have that, here on the Earth. And so that makes them really valuable. But my research has been mostly with the asteroids. And, you know, I think the thing is that sometimes people are really surprised to learn that, you know, meteorites are all different, just like Earth rocks are all different, right?

Nancy Chabot: I mean, there's really no reason that you would think everything out there in space would sort of be the same. People have this one vision a lot of times have this is what a meteorite is and it's like, no, no, no meteorites are sampling this huge diversity of different bodies. I mean, some of them are, you know, 4.5 billion years old, they predate the planets. They're like the garbage bag and leftovers that didn't form the planets, but they let you look back into the first solids that solidified in the solar system, what was going on in our solar system before there were planets. And then some of them made, like, mini-planets, planetesimals, right, where they melted, and they made these metallic cores and these rocky mantles and had volcanic processes on the surface. And we have samples of those too, and they all look different. But similar to some of the Earth’s rocks to it just shows you the you know, the Earth is just part of our solar system. So it really ties it all together.

Jim Green: Meteorites that are different. Does that mean they're generated or put together in different places of our solar system?

Nancy Chabot: Yeah, maybe. We think that some of the stuff we're learning from meteorites right now, some of the cutting-edge research has to do with these isotope systems, which is a really detailed measurement, again, showing you the power of meteorites and using Earth-based analysis to do this. And now we have samples from both of these populations of the inner solar system and the outer solar system potentially. And that's one reason things can look different. But things can also just look different depending on how big the planetesimal grew. So if things never grew very big, they didn't melt. And so you can retain these primitive characteristics. But you know, if things grew to 10 kilometers, 100 kilometers, or larger, then that could have different processes that go on as well, just because the bodies are different sizes. But yeah, where they formed in the solar system can have different compositions. You know, this might be why Mercury looks different than Mars, for example. So meteorites help to put all of this into context.

Jim Green: Well, I heard that you've been to Antarctica five times. What was that like? And what were you doing there? Looking for meteorites?

Nancy Chabot: I was so fortunate to go the first time when I was in grad school with the Antarctic search for meteorites program, ANSMET. Yeah, which is a great program that joint with NSF and NASA and the Smithsonian. It’s been going on for decades, and is hugely successful at collecting meteorites. Antarctica is just an amazing place to go get meteorites, and I got to go the first time as a grad student.

Jim Green: Did you have an easy time or was it hard and cold?

Nancy Chabot: Antarctica pretty much is always cold. But it was an amazing experience. So, what we do for ANSMET, every season, is we get teams of between four to eight people. And then we get dropped off in the middle of nowhere on these blue ice fields, where you're 100 miles away from the next people in the entire world. The Sun is up 24 hours a day when we go. And the landscape is really other-worldly in a lot of ways. Big horizons and ice, a lot of ice. There's some mountains too. And it's very different than your, my life and most other people's lives on a daily basis. You're chipping ice in order to get your water. You're you know, getting to know your other campmates very, very well. (laughs) Because there's nobody else around. It's hard. I mean, for sure. But it's, it's amazing. And it's a great opportunity that everybody who's been able to go with ANSMET really appreciates and this, sort of this, moment in your life that you would never trade.

Jim Green: So you get in snowmobiles. And you, you start across the ice sheet. And and you see these black objects, and they're meteorites. Any of particular interest to you?

Nancy Chabot: What's amazing about Antarctica is you'd be down there for six weeks, and an average field season finds between 100 and over 1000 meteorites during that period of time, just in those few weeks. Depending on where you are, you could find 100 a day, sometimes. They're just sitting there collected by these natural ice movements waiting, you know, sort of, for us to find them and then share them with the world so we can uncover all their secrets. I don't know it's hard to pick favorites among meteorites, I have my own personal ones, I personally worked on iron meteorites a lot. And pallasites are closely related, which are made of olivine and metal intermixed together.

Nancy Chabot: Pallasites are a type of meteorite that we think comes from the core mantle-boundary of an asteroid, because they have really beautiful olivine crystals in them, like gem quality.

Nancy Chabot: I remember one time we were on a pretty small field team, there was four of us. And we were driving around on our snowmobiles. And we found this giant pallasite. In fact, it was so heavy, I couldn't pick it up. (laughs) We had to get like two people to put it onto their, onto this sled.

Nancy Chabot: And we're like, wow, this is great. But then you know what? Then we found another one, another giant one! And then we found another giant one! And it turns out there was this whole strewn field of pallasites along this site. And it never got old. you might think, oh, after a few days, aren't you tired of finding these giant pallasites from space? And it's like, nope, nope, just keep bringing it on. I’ll take all of them that you would give me.

Jim Green: Well, you've also worked on NASA's MESSENGER to the planet Mercury. How did you get involved in that mission? And what was the most exciting results that that you found in analyzing that data?

Nancy Chabot: Yeah, I feel like I've been really fortunate to have a lot of opportunities. I mean going to Antarctica, you know, five times was was one of those and then getting this job here at Johns Hopkins Applied Physics Lab allowed me to become involved with the MESSENGER mission. I actually started off on that mission helping run their website. So I was sort of updating the science content for the website. And one of the things related to that was putting out featured images from the camera. Well, then it turned out, “Hey, maybe you want to get involved with the camera team?” And I'm like, “Yeah, I want to get involved with the camera team. That sounds amazing.” You know, and, and then by the end of the mission, I was actually the lead scientist for, for the camera on MESSENGER and in charge of the geology discipline group. So leading a lot of the science that was going on.

Nancy Chabot: And I think one of the things that I love working in planetary science is that you always have to learn new stuff. And so you know, here, I came from this physics background. And then I was doing this geochemistry of meteorites and going to Antarctica. And then I had to learn all about spacecraft cameras and image analysis and looking at the planet. But it was really, I just relished and appreciate having had that opportunity.

Nancy Chabot: So you asked about some of the like, most exciting parts. Before MESSENGER, we only seen 45% of the planet. Like literally, here's another planet in our solar system. And we don't even know what it looks like, right?

Nancy Chabot: And so these images are just streaming back. And they're parts of the planet that we've never seen before. We're literally mapping the planet for the first time creating the first global view of what it looks like. And I just can't. It was like a childhood dream come true to like, look at my computer each day and see these new views of something that we had never seen before. And I know I'm not the only one on the team that felt that way. And that was also, made it so rewarding to be on this team where we were doing this all together and so much data was coming in and really revealing this new world right before our eyes.

Jim Green: Well, you know, the next mission to Mercury is the ESA-JAXA BepiColombo mission. And I hear you're involved in that too.

Nancy Chabot: I am.

Jim Green: How did that happen?

Nancy Chabot: So when I worked on MESSENGER, I started to specialize a lot on ice in the poles. So there's these regions on Mercury that never get direct sunlight. It just doesn't have much tilt. And so these craters are just always very, very cold. And there's ice in them. MESSENGER made a lot of good discoveries in order to tell us about that. And, and that's sort of what positioned me then to be able to join the BepiColombo team to take that to the next step with BepiColombo, and what is going to tell us about the ice at the poles of Mercury.

Jim Green: Well, you know, another fantastic mission that's about to launch is called the Double Asteroid Redirection Test, or DART. What is DART going to do? And how does it do it?

Nancy Chabot: DART is an amazing mission. It's launching very soon. And it is a planetary defense mission. And what it's going to do is it’s purposely going to crash a spacecraft into an asteroid to move it a little bit. And this is the sort of thing that you might want to do if there was an asteroid in the future that was headed towards the Earth and you wanted to move it a little bit so it wouldn't hit the Earth.

Jim Green: Wow, that sounds fantastic. Well, what asteroid are you gonna hit and deflect?

Nancy Chabot: So like the name says, it's a double asteroid system, hence the double asteroid redirection test, and there's two asteroids. There's the larger Didymos, which is 780 meters in diameter and it has a small moon that's named Dimorphos. and it goes around every 11 hours and 55 minutes, it's 160 meters in diameter. So smaller, much smaller than Didymos. We know this because telescopes here on the Earth have been looking at these asteroids for decades. And they've mapped this out. They’ve discovered this double asteroid system. And so what DART is going to do is it's going to target Dimorphos, the smaller of those two asteroids, and it is going to hit into Dimorphos.

Nancy Chabot: And it's going to ever so slightly deflect how Dimorphos goes around Didymos. So moving the asteroid, just a tiny bit, about how it goes around the larger asteroid. And so it's a small little nudge, this is what you would want to do for planetary defense. Planetary defense with a kinetic impactor technology like this is definitely about deflection not disruption. This is in no way looking to blow the asteroid up. It's just going to give it a small nudge and make a small change in its period. And we think it might be about 10 minutes, so maybe 11 hours and 45 minutes will be what the telescopes measure after DART’s collision. But we don't know for sure, and that's one of the main goals for the DART mission is to make that measurement.

Jim Green: What kind of damage would an asteroid the size of the moon of Didymos cause if it hit the Earth?

Nancy Chabot: Yes, Dimorphos at 160 meters is one that we really are concerned about, if something the size of that hit the Earth. So sort of a kilometer and up are the size that you worry about for global extinction events. So dinosaur killers, if you will, and happy to say that we've found the majority of those asteroids, the large majority over 90%, none of those are on a collision course with the Earth. We're tracking them. So global extinction events, and like the dinosaurs are not in our future. But these few hundred-meter size ones – we've only found less than half of the population actually. So we are still looking. And that's an important part of planetary defense. planetary defense is not just about deflecting asteroids, it's also finding all the asteroids, figuring out where they are characterizing them, keeping track of them. But then it's also taking this first step to be ready in case you needed to. So something on the size of Dimorphos, if it was to hit the Earth, would be regional devastation, it would be hundreds of kilometers wiped out. And sort of, you know, devastating over large urban areas or something the size of a small state in the United States. So regional devastation. It would be catastrophic.

Jim Green: Is there a chance in the future that it will come around and hit the Earth?

Nancy Chabot: Yeah, there is no chance that Didymos and Dimorphos, or a danger or a threat to the Earth. They're not on a collision course with the Earth in the future. That makes them really appropriate for this first test. You know, being the double asteroid system, that binary asteroid system really is enabling for the telescopes. But of course, if you're going to do a first test of asteroid deflection, you want to do it on something that's not a danger to the Earth as well.

Jim Green: Well, how fast is DART moving when it impacts Dimorphos?

Nancy Chabot: So DART comes speeding in really fast, 15,000 miles per hour. It needs to be going really fast, it needed to give this asteroid a small nudge, because the spacecraft itself, the main body of it without the solar arrays is about 100 times smaller than the asteroid that it's trying to move. So you can see you have to come in pretty fast just to give it this small nudge.

Jim Green: Well, you know, that impact’s going to happen next year. Will the public have an opportunity to see it if they look up into the sky?

Nancy Chabot: The impact is happening late September, potentially, October 1st, we'll know once we launch for sure what the impact date is. And this time of 2022 was specifically chosen, because the distance between Earth and Didymos is at a local minimum. So it's actually not going to be this close to the Earth again for another 40 years. So that enables the telescopes here on the Earth to get the best data possible. But we're still going to use some pretty big telescopes in order to be able to make that measurement.

Nancy Chabot: So just looking up, you won't necessarily be able to see a bright flash and a lot of ejecta all over there. But, Hubble Space Telescope is going to give it a try. And James Webb Space Telescope, hopefully, will also be giving it a try to get whatever data they can. So, but we are going to be streaming the images back to Earth, one per second. And so we'll be getting these smart-nav images sent back to Earth at the same time. And we'll be seeing them one a second, one a second, it's not going to look like much until you get really close. And then it's going to be speeding in, show the surface of the asteroid, and then the images will stop. So people can look forward to seeing that at least.
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Gravity Assist: How to Move an Asteroid, with Nancy Chabot (2)


Nancy Chabot and Andy Rivkin, researchers at Johns Hopkins University Applied Physics Laboratory, are pictured with the DART spacecraft. Credits: NASA/Johns Hopkins University Applied Physics Laboratory

Jim Green: Well, let's hope they stop, because that means you’ve impacted Dimorphos.

Nancy Chabot: (laughs) Yeah, that's, it's, that last image is going to be pretty spectacular for sure.

Jim Green: So Nancy, after the impact of DART on the moon of Didymos, what happens next?

Nancy Chabot: Well, what happens next is there's an Italian CubeSat called LICIACube. And it actually makes a close flyby three minutes after DART’s collision. And it captures some spectacular images of the ejecta and the collision event itself. And but it's actually going to take it a few weeks to send all those images back to Earth. So those images will be streaming back. And we'll be looking forward to them to see the ejecta pattern. But then the telescope here on Earth also get to work because they have to map out how much this period is changed. And so but you can't, if this is not a single measurement.

Nancy Chabot: In order to do that, they have to observe the asteroid over time, because the way that you map out the period is what's called a light curve. That's when the brightness changes. And right now that brightness changes every 11 hours in 55 minutes. So to map out what the new one is, you need to get a lot of measurements over an extended baseline, to be confident in how much you've changed it. So the telescopes will do that, but then the moon will come up, which you know, the moon has a lot of good redeeming features about it. But for ground-based astronomy, it kind of gets in the way sometimes.

Nancy Chabot: So you have to kind of wait those weeks, and then you get to go look again, and try to make some more measurements. And so it'll really take actually, you know, maybe about a month, month and a half until we have a good measurement of how much we've deflected this asteroid. But the telescopes will actually be able to work until March of 2023, to look at this system. Again, this is why we’re targeting 2022 for the DART collision. So the telescopes here on Earth can make these fantastic measurements for many, many months, to measure this deflection very accurately.

Jim Green: So where's the spacecraft now? And when is it going to launch?

Nancy Chabot: So the spacecraft is in California, it's going to be launching from Vandenberg Space Force Base, and the launch period opens November 23. Pacific time. So the evening of November 23, on the California coast, 10:20pm.

Nancy Chabot: Hopefully, it'll just go right then.

Jim Green: Wow.

Nancy Chabot: It's got a really long launch period. And so it can actually extend into February. But we're targeting November 23, and just ready to get into space.

Jim Green: That flexibility of launch period, is that because you actually have an ion engine on board of DART?

Nancy Chabot: Well, we do have an ion engine onboard DART. And we're excited to be testing that out as a demonstration. But it actually has more to do with that DART never actually gets very far from Earth, because we're going to this near Earth asteroid and we're targeting this near Earth asteroid at the time when the distance between it and the Earth is minimized. And so DART sort of launches and just kind of stays pretty close to Earth the whole time. And so that that gives you a lot of flexibility in the launch window.

Jim Green: Well, that's gonna be absolutely fantastic. But now that you've had experience with meteorites, is there any connection between Didymos or Dimorphos and the meteorites that you've studied?

Nancy Chabot: Yeah, I think it's this is kind of fun to like, bring it full circle. So from spectral observations of Didymos that we've done with telescopes here on the Earth, we know that it's linked to a meteorite type that's called ordinary chondrites. And ordinary chondrites are some of these primitive building blocks of the planets. So they've got grains of metal next to grains of rock, and you can date these back to ages that are earlier than the planets. And so if that's what the main moon Didymos is composed stuff, we don't actually have any measurements for what the spectral type of Dimorphos, but from models of how binary asteroids form, they all predict that it should be the same material as Didymos. So this is, this is a fascinating type of meteorite, it's actually the most common type of meteorite to hit the Earth. And then that makes it extra relevant for planetary defense, which is applied science, and you want to be doing this on the most relevant, appropriate common type of targets. So that makes these Dimorphos even more appropriate for this first planetary defense test.

Jim Green: Yeah, this is really exciting our ability for the first time to figure out ways that we may have to in the future, defend our planet. So all eyes are going to be on APL and what you guys are doing, to be able to start the process of helping the Earth survive in the long run. So thanks much, and I'm really looking forward to it.

Nancy Chabot: Thanks, I'm super looking forward to it too. And I think it's really exciting that it, there's a lot more for planetary defense yet to come to, I mean, you know, the follow on with the NEO Surveyor mission to find all the asteroids and get a dedicated space telescope up there. And then there's the HERA mission, the European Space Agency is sending to the Didymos-Dimorphos system that will get there in 2026. And they'll be able to see that crater made by darts and, and get the mass of Dimorphos and really characterize the system. And so DART with HERA will do more together than any one mission can combine on their own. And I think that's really exciting for planetary defense, too, because it is, it is a global issue, it affects the entire planet. So working internationally and having that collaboration and having a whole team of doing this really makes it very rewarding.

Jim Green: Nancy, you know, I always like to ask my guests to tell me what was that event? person, place or thing that got them so excited about being the scientist they are today? And I call that event a gravity assist? So Nancy, what was your gravity assist?

Nancy Chabot: So when I was a kid, I really loved Star Wars. I thought Star Wars was amazing, was like the most amazing thing I had ever seen. And I used to, I really liked the story. But what I really liked about it was thinking about these different worlds and seeing them on the big screen, like worlds with two suns, and worlds made out of ice, and worlds where people lived in the clouds and asteroids with giant caverns. And I would ask my parents, how did they come up with all of this? And my parents told me at the time: They just dreamed it. And I used to go to bed at night and like, close my eyes and be like, tonight's the night I'm going to dream like Star Wars that it's gonna be amazing. I’d wake up in the morning like disappointed. My dreams were not that good. But I think that that sort of like wonder and fascination just really stuck with me. And you know, in some sort of way that maybe I haven't fully realized. And, and now, I mean, I literally feel like I'm living the dream. I don't have to close my eyes anymore. It's like, I'm a part of this part of NASA's exploration of the solar system to all these new worlds, and it's just amazing.

Jim Green: And now you know that some of those dreams are coming true, where we're finding planets that are orbiting two stars. And, and now you're working with asteroids and deflecting them. So it's, in a way, it's a dream come true, Nancy.

Nancy Chabot: It indeed is, for sure.

Jim Green: Well, thanks so much for joining me and discussing your fantastic career and what you're up to. I'm really looking forward to these missions,

Nancy Chabot: As am I, and everything else that comes after that as well. I mean, it's just great to be part of all of these teams. That's one of the things actually that I really like about this field as well is that it takes a lot of people to accomplish all of this. It's way more than any one of us could do on our own. But together we're doing these amazing things.

Jim Green: Indeed. Well, join me next time as we continue to journey to look under the hood at NASA and see how we do what we do. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-how-to-move-an-asteroid-with-nancy-chabot
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #35 dnia: Lipiec 02, 2023, 10:29 »
Dr. Martin C. Weisskopf byl głównym naukowcem  misji Chandra i IXPE.

Gravity Assist: A New Set of X-Ray Eyes is Launching, with Martin Weisskopf (1)
Dec 3, 2021


This image of the Crab Nebula combines data from five different telescopes: the VLA (radio) in red; Spitzer Space Telescope (infrared) in yellow; Hubble Space Telescope (visible) in green; XMM-Newton (ultraviolet) in blue; and Chandra X-ray Observatory (X-ray) in purple.  Credits: NASA, ESA, G. Dubner IAFE, CONICET-University of Buenos Aires et al.; A. Loll et al.; T. Temim et al.; F. Seward et al.; VLA/NRAO/AUI/NSF; Chandra/CXC; Spitzer/JPL-Caltech; XMM-Newton/ESA; and Hubble/STScI

NASA is about to launch a new spacecraft to look at the universe in X-ray light. The Imaging X-Ray Polarimetry Explorer, IXPE, will look at extreme objects such as black holes, neutron stars, and supernovae, asking fundamental questions about how high-energy light gets produced. The mission’s principal investigator, Martin Weisskopf, based at NASA’s Marshall Space Flight Center, has been studying these objects for more than 40 years with other telescopes including the Chandra X-Ray Observatory. He discusses some of the fascinating objects Chandra has looked at, and what IXPE may soon reveal about them.

Jim Green: To reveal important secrets of the universe, we use light that humans cannot see. But our spacecraft can.

Jim Green: Let’s talk to an astrophysicist who has X-ray vision.

Martin Weisskopf: X-ray astronomers’ main interests -- they're mostly interested in supermassive black holes at the centers of galaxies and how the universe evolves.

Jim Green: Hi, I'm Jim Green. And this is Gravity Assist. We're going to explore the inside workings of NASA in making these fabulous missions happen.

Jim Green: I'm here with Dr. Martin Weisskopf. And he is the project scientist for NASA's Chandra X-Ray Observatory and the chief scientist for X-ray astronomy in the Space Sciences Laboratory at NASA's Marshall Space Flight Center in Huntsville, Alabama. I have known Martin since I started working at Marshall Space Flight Center in 1980. So it's a real treat for me to have Martin on gravity assist. Welcome.

Martin Weisskopf: Thank you, Jim. It's nice to see you again. I got there in ‘77, three years before you.

Jim Green: We've been long term friends and long term NASA employees, and you've got so much experience. But your field of interest is really studying the universe with X-rays. How did you get interested in doing that?

Martin Weisskopf: I went to Columbia University as a postdoc, because I wanted to switch fields. So I did my PhD in atomic physics. And I was going to switch fields every five years, and they were doing X-ray astronomy at the beginning. And so it was very exciting. Sounding rockets!

Jim Green: Wow, sounding rockets. Yeah. And we still use sounding rockets for many, many purposes. Where do we find X-rays in our universe?

Martin Weisskopf: The amazing thing is, and very surprising over the years, is that you find them everywhere. X-rays are light at extremely high energies. And they're found in regions where there's extremes of matter at high temperatures, millions of degrees, super strong magnetic fields, things like that.

Jim Green: You were the project scientist for the Chandra X-Ray Observatory mission, one of NASA's great observatories.

Jim Green: Martin, when did Chandra launch and what were some of its goals?

Martin Weisskopf: Chandra launched on July 23, 1999. It's supposed to launch two days or three days earlier and every day there was some reason we had to postpone, but the third time was a charm.

I was hired in 1977, after Headquarters decided it was a great idea, this kind of X-ray telescope that could look at X-ray objects with much higher sensitivity and better angular resolution than before. I was hired at Marshall in 1977. They all thought I was too young to be the project scientist. Now they think I'm too old to be the project scientist. But, just, you can't win.

And its scientific goals were really huge. They were to try to understand how the universe works, especially through its X-ray emission. Exploring the universe to try to see what kind of X-ray sources were out there. Were all classes astronomical objects, X ray sources? And if so, why? Why is this happening, you could understand how neutron stars might be in a binary system, might get their energy from gravity, kind of wave your hands, normal stars, magnetospheres are something we've been trying to understand for decades. And we're still trying to understand, they're very complex. But these are the kind of goals to really nail down the emission mechanisms of astronomical objects and to understand the evolution of the universe.

Jim Green: What has Chandra been finding out recently?



Martin Weisskopf is the principal investigator of the IXPE (Imaging X-ray Polarimetry Explorer) satellite. Credits: NASA

Martin Weisskopf: Well, Chandra has made, most recently, a fantastic discovery. It’s discovered evidence for a planet in another galaxy. Isn’t that amazing?

Jim Green: Indeed, I can hardly imagine that. And it's a beautiful spiral galaxy too. How did that happen?

Martin Weisskopf: Well, it happened because the, the scientists who wanted to take the observation wanted to study that galaxy. And they knew about these various candidate stars that have possibly planets around them. And they just stumbled into the right information.

Jim Green: So for them to be able to make that fantastic measurement, they actually had to make many observations over and over again, waiting for the right time for the planet to move in front of a very active X-ray star. Isn't that right?

Martin Weisskopf: That's right. And there, it's the active X-ray star and the galaxy itself. 

Jim Green: Well, what kind of star was it that has to emit these huge high energy X rays?

Martin Weisskopf: This is one of the great amazing, interesting things. Not only stars like the Sun have solar flares, but other stars flare and we found that we see X-rays for various different reasons, from essentially all categories of stars. Although that's not the X-ray astronomer’s main interest. They're mostly interested in supermassive black holes at the centers of galaxies, and how the universe evolves.

Jim Green: Well, what's been one of your favorite Chandra discoveries?

Martin Weisskopf: Oh, my. I would have to say, because I've been interested in this target since I did my first experiments in 1970, is the Crab Nebula and its pulsar. This is a source where a star exploded and left and nebulosity around where the material of this star is running around and crashing into the interstellar medium and getting very hot and it left a compact object.

Martin Weisskopf: When I say compact, I mean compact, about the size of a city like Huntsville, Alabama, but weighs as much as the Sun. The density on the surface of this star is like 10 billion people per raindrop. So these are really cool stars and we want to study them. And I have been studying that object, the Crab and its pulsar, since the beginning of my career and for one reason or another, then with Chandra I did some discoveries, with Hubble, with various different things. And I hope to with this new instrument that I'm fortunate to be principal investigator of IXPE, the Imaging X-ray Polarimetry Explorer.

Jim Green: Those collapsed stars, those neutron stars, as you say, that are emitting enormously intense X-rays. How are they doing that? And what do we know? And how can we call them pulsars? Does the radiation turn on and off?

Martin Weisskopf: It does. That's one of the exciting things the radio astronomers discovered the first pulsars and X-ray astronomers quickly followed with X-ray pulsars, some of which are also radio pulsars, some of which are not. The X- rays do pulse, like that one in the Crab pulses 33 milliseconds is the period, it’s very fast. And we even have pulsars that are sub-millisecond in rotation. Where does the energy come from? Well, the quick answer is from the fact that these objects are spinning. So if you're spinning, you have angular momentum, you store energy, and we watch the systems slow down. So they're losing energy, that energy goes into producing charged particles and X-rays.

Jim Green: One of the properties of all light is that it has a polarization to it. What exactly is polarization and why is that so interesting to us?

Martin Weisskopf: Light is electromagnetic wave. And that's a fancy word by saying that in addition to the direction of travel at right angles to that direction, there's an electric field and a magnetic field.

Martin Weisskopf: And if each X-Ray has all the electric fields lined up, we call it 100% polarized. If on the other hand, all of the electric fields are at different orientations, it’ll average to, their net direction will average to zero, it’s unpolarized. So the question is, we want to measure polarization from the X-rays from objects and see what it is and then we have a theory that explains it. And in preparing for our missions, we have done a lot of theoretical work to try to anticipate where we might see polarization and some of these things are really neat.

Jim Green: When I think of polarization, I think of going out onto the lake and light coming down and reflecting off the surface of the water. And then that produces a glare. And that's polarization too.

Martin Weisskopf: Yes, what's happening there is when the light comes in and reflects off the surface, that reflection only allows one orientation of the electric field, the one that's parallel to the surface to come through.

Martin Weisskopf: But what we're trying to do is we're trying to do is to measure the glare. If you like. Not to get rid of it, we want to measure it. The light that we're seeing from the lake and the glare is polarized. And if you put it a polaroid into, to suppress certain directions of the electric vector, then you get rid of the glare. Now we're not trying to get rid of the glare, we want to see how much glare is there. And which way is it polarized?

Jim Green: The more the glare, the better.

Martin Weisskopf: That would be nice. That would be nice.

Jim Green: I understand that you had an experiment many years ago to measure the polarization of X-ray light. What was it and what did you find out?

Martin Weisskopf: Now that's amazingly enough, that in 1971, on February 22, flew a sounding rocket from Wallops Island, Virginia. And we looked at that source, the exploded star, the Crab Nebula, and its pulsar, and lo and behold, in that little rocket experiment, which was five minutes above the atmosphere, we measured the integrated polarization from that system. And that, at the time, was extremely important because how were the X-ray is being produced? The answer was synchrotron emission, a type of emission where electronic gets accelerated in a magnetic field. And if that was the correct theory, we would see strongly polarized light. And we saw about 20% polarization, which is very strong in astrophysical terms. And so yes, we nailed it. And then we did a follow up experiment on a satellite called Orbiting Solar Observatory 8 in the mid-70s. And measured it, 20 plus or minus 1%. So we nailed it.

Jim Green: Wow, that's fantastic to be on the ground floor of using an important wavelength that we can't see normally, and making new and exciting discoveries using these concepts of polarization. Now, most recently, you became the principal investigator for the Imaging X-ray Polarimetry Explorer or IXPE. What’s IXPE going to do?

Martin Weisskopf: Well, IXPE is the first mission that's dedicated to X-ray polarimetry. That's what it does. It has a beautiful, incredible technology that was started at Marshall Space Flight Center, and then developed independently and by their colleagues in Italy, which provided polarization-sensitive detectors, and we at Marshall built X-ray telescopes to put in front of them. We have three optics and three detectors in IXPE. And we're going to spend all of our time looking at the bright sources and trying to measure the polarization for the first time. And confound the theorists.
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #36 dnia: Lipiec 02, 2023, 10:29 »
Gravity Assist: A New Set of X-Ray Eyes is Launching, with Martin Weisskopf (2)


NASA’s Martin Weisskopf and colleagues from Columbia University in 1971 pose with the Aerobee-350 sounding rocket they used to detect X-ray polarization from a celestial object for the first time. Left to right are Robert Novick, Gabriel Epstein, Weisskopf, Richard Wolff, and Richard Linke.

Jim Green: I'm sure that will happen. But what are some of the objects that you're going to look at with IXPE?

Martin Weisskopf: Yes, well, one class of objects is what we call stellar mass black holes. These are black holes, they weigh about 10 times to 20 times as much as the Sun. And they're in a binary system, they are orbiting around a normal star and from near the black hole, we can't see the black hole, but from near the black hole, the conditions are right that X-rays are produced. Now, one of the things that our simulations in theory tells us is that the polarization as a function of energy depends on the spin. So we will not only measure the polarization as a function of energy, just to understand what's going on, but measure the spin of the black hole in a way that's never been done before. That's one of the many cool things that IXPE will try to do, and I'm sure will do.

Jim Green: Well, you know, I'm really excited about other things that IXPE can do, such as looking at active galactic nuclei. What do we expect to see when we do that? The, the center of galaxies that are not ours?

Martin Weisskopf: Yes. So we come back to first of all, we come back to black holes again, because we find it that the center of galaxies are supermassive black holes, millions to billions the solar mass. And often, as part of the way these physics of how these things interact with the galaxy, they form jets. So there's jets of X-ray emitting material that's pouring out from this object. And we’re trying to understand how that happens. And that will give us some further insight into exactly the details of how do these beasts produce all this energy, not only X-rays, but visible light, radio waves, etc.

Jim Green: So the launch is coming up soon. And once you get it on orbit, how long does it take to check it out before you really start observing things?

Martin Weisskopf: Yeah the launch is in early December. Right now we have the target date of December 9th. And we have a 30-day period from the time of the launch to check everything out. A very important aspect of the, that sequence is a week after launch, we have a boom, an expandable boom that separates the telescopes from the detectors. That has to work. We've tested it up a lot, you can imagine, but it has to work. Because if it doesn't work, we're in trouble. But I'm very confident that it will. And that happens a week into the launch and then we turn on the instruments for the next three weeks, check them out, and then we start taking data a month into the mission.

Jim Green: Well, you know, since Chandra didn't measure X-Ray polarization, IXPE is a huge advance. Are you going to be using the same targets that Chandra did, or even more?

Martin Weisskopf: We'll be using many of the targets that Chandra has done, and we're, especially for the imaging part where we're looking at polarization of extended objects, we will be using the Chandra images because Chandra can see a dime at 12 miles. IXPE can't do that. Chandra is subarcsecond resolution. IXPE is 30 arcsecond resolution, and we will be using Chandra images to guide our images.

Jim Green: Well, will there be opportunities to look at the same object at the same time between IXPE and Chandra?

Martin Weisskopf: Yes, in fact, some of my colleagues have already proposed such and we're looking at the galactic center at the same time where, with Chandra, as we are with IXPE, so yes indeed, a lot of science gets done, as you know where well, by using the whole suite of instruments, scientific instruments that NASA has provided -- things like Chandra, the NuSTAR, which is a higher energy experiment, Hubble, and then hopefully JWST in the future. So, very near future I might gather too. So that’ll be very exciting.

Jim Green: Yeah, that's fantastic. Now is the launch out of Kennedy Space Center?

Martin Weisskopf: Yes, it's at Kennedy Space Center. But the orbit will end up going around the equator. We do that to, to keep our charged particle background low. And so the Falcon 9 will take us into orbit, maneuver us down to the equator and then let us go.

Jim Green: That's fantastic. Well, what are you personally most looking forward to about IXPE observations?

Martin Weisskopf: One is the Crab Pulsar, as a function of pulse phase. Polarization as a function of pulse phase. I tried to do that years ago, we just didn't have sensitive enough polarimeters, want to see that done. The other one is one of the magnetar experiments.

Martin Weisskopf: Magnetars are called that because we think their magnetic fields are 10 to the 15th Gauss, 1000 times more than a conventional neutron star. And it those field strengths, the physics changes where you have to worry about fancy things like not classical electricity and magnetism. But stuff like quantum electrodynamics, that is, the quantum theory of the fields is very important.

Martin Weisskopf: There was a physicist who in 1934 wrote a paper on what happens to propagation of light when magnetic fields get beyond the critical field of about 10 to the 13 Gauss. That was my uncle Victor. And so I would just love to be able to have, do an experiment that says yes, quantum electrodynamics is right in this context of a magnetar, and I quote Vicky's paper and it just feels so good, it feels so good. I would have loved to have done that while he was alive. But still, I'm looking forward to that.

Jim Green: Oh, wow. I understand completely. Well, Martin, I always like to ask my guests to tell me, what was that event or person, place or thing that got them so excited about being the scientist they are today? I call that event a gravity assist. So Martin, what was your gravity assist?

Martin Weisskopf: It's a very tough question, in the sense I've been fortunate enough to have several. But I think that first experiment we talked about when I was a young postdoc at Columbia. After doing the data analysis in my office, I realized at that moment that I was the only person ever alive that I had ever existed that knew that the Crab was 20% polarized.

Martin Weisskopf: And it was just, the feeling of awe came over me. I thought I was in church for a few minutes, and that was my first such moment. And being able to be project scientist, which I still am for Chandra, to have been one of the people to build what we call, well, one of my scientists called, a scientific cathedral, one of the great observatories of NASA has been another moment that actually keeps going. We built it designed for three years with a goal of five. We celebrated our 22nd year this year, and the observatory keeps putting out fabulous new unexpected results.

Jim Green: Yeah, indeed, it does. But it also sounds like your family has been involved in astrophysics over the years. What's that been like?

Martin Weisskopf: Well, I have a, I have a family of intellectuals that are all smarter than I am. My uncle was a physicist. My father was an economist, my mother taught  romance languages. My aunt was a psycho, psychologist, taught that at university. So it's just nice, little frightening. Can't read my father's papers, because he uses words that are longer than I can pronounce. I can read my uncle's papers, because the math is way beyond me. But I've done a few things too. And I'm experimentalist, and I love building hardware.

Jim Green: Well, that's wonderful. And congratulations on being the PI of IXPE. Martin, thanks so much for joining me in discussing your fantastic career, and the opportunity to look forward to even more results.

Martin Weisskopf: I hope so. Just takes a little bit of luck and a lot of hard work by hundreds of people throughout the world. And it's showing. And NASA has played such an important role in this. If you young person want to get into something exciting, no matter whether it's from the engineering, management, science or any other aspect of it, come to work with us at NASA. You'll love it.

Jim Green: Well join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Dec 3, 2021
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-a-new-set-of-x-ray-eyes-is-launching-with-martin-weisskopf
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #37 dnia: Lipiec 09, 2023, 06:46 »
Rozmowa z głównym naukowcem i starszym doradcą ds. klimatu NASA od 2022 roku.
Do 2050, wg planów, ma być osiągnięty cel zrównoważonej emisji CO2 (zerowej emisji netto).
Ale czy się uda. ?
Przez jakiś czas powinno być jeszcze coraz bardziej ciepło.
M.in. misja SWOT czy instrument EMIT zainstalowany na zewnątrz ISS pozwalają pozyskiwać dane klimatologiczne.

Cytuj
Kate Calvin: So warming will stop when we get emissions to what's called net zero, so that effectively any extra carbon dioxide we're putting into the atmosphere, we're also taking out. And at that point, you know, there's some other nuances in that. But that's really that's how you stop warming.

Gravity Assist: Meet NASA’s New Chief Scientist and Senior Climate Advisor, with Kate Calvin (1)
Jan 28, 2022


Close-up view of sea ice floes from NASA's DC-8 Research aircraft. The dark features on the ice are melt ponds, and the dark areas of between the floes are open water of the Arctic Ocean. Credits: NASA/Steve Wofsy

Climate change is one of the most important issues facing our planet, and NASA has lots of space missions and programs in the works to monitor and understand its drivers and effects. Kate Calvin, NASA’s new chief scientist, is also the agency’s senior climate advisor. In this episode, Kate previews  upcoming Earth science missions and discusses cutting-edge research endeavors to explore climate change.

Jim Green: The Earth's climate is changing. And NASA is making key observations to see what it's all about. 

Kate Calvin: Climate change is about more than just changes in temperature. There's a whole host of other earth system changes that come along with this, like changes in the water cycle, which can lead to more floods and more droughts at the same time.

Jim Green: Hi, I'm Jim Green. And this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: Welcome back to Gravity Assist. I'm your host, Jim Green, and I have a new job.

Jim Green: In January 2022. I retired from NASA, but they hired me back working on some very special projects.

Jim Green: So in our first episode of season six, it gives me great pleasure to talk to the new chief scientist of NASA, Dr. Katherine Calvin. And she is also the agency's climate advisor. You know, climate change is such an important topic, and we are thrilled to have Kate on board at NASA.

Jim Green: Kate is a distinguished climate scientist who comes to us from the joint Global Change Research Institute at the Pacific Northwest National Laboratory. She has also been a research scientist at the University of Maryland in College Park. Welcome, Kate, to gravity assist.

Kate Calvin: Thanks, Jim. It's great to be here.

Jim Green: First, tell us a little bit about what are you going to be doing in your new role?

Kate Calvin: Yeah, I'm really excited. I'm now the chief Scientist and senior climate advisor at NASA, and as senior climate advisor my role is really to connect the climate science within NASA. NASA does a lot of climate science throughout all of the mission directorates and trying to bring that together so people know what they're doing and what everyone's doing. I'm also going to be working towards communicating that science externally, working with other agencies in the United States, and communicating with the public. In general, as chief scientist, my role is really broader than that, focusing on all of NASA science. 

Jim Green: Wonderful, this is really going to be a wonderful era, where NASA takes a larger role in explaining the changes that are occurring on our beautiful blue planet. Well, can you talk about how you got into climate science? Is this something that you've always wanted to do?

Kate Calvin: So I My background is in math and computer science and engineering. And when I was going into grad school, I knew I liked math and computer science, but I wasn't exactly sure what I wanted to do with it. I've always loved being outside, though. So as a kid, we grew up around boats, and I did a lot of camping. Over time, I got more into hiking and biking. And climate change was one of these ways of combining my technical skills with something that really mattered to me. So when you spend a lot of time outside, you develop an appreciation for nature. And you notice weather. And climate change is a really nice way for me to tie together something that I loved was something I knew how to do.

Jim Green: Well, you know, a lot of people get confused between weather and extremes of weather, and what we talk about as climate of the Earth. Can you give everyone a little insight as to the difference between those two?

Kate Calvin: Sure, from a scientist, what we like to think of is: Climate is long term weather. So if you're, you know, then if you look at how many hot days you have any year, there's going to be some variation from one year to the next over time, if you have more hot days, that's a climate signal. The analogy I heard most recently, actually, on one of your podcasts was about wardrobe, though. And so you can think about your outfit for the day being weather and climate being your wardrobe. And so I think if you think about climate change in that context, over the pandemic, I think we all bought a lot more sweatpants since we were working from home. And so that's sort of a shift in our wardrobe. So you could still wear jeans, because that was the weather that you had access to. But with more sweat pants in there, you're seeing more and more sweatpant days. And so in the in again, in the analogy of climate change, you know, your wardrobe is climate. And so as we get warmer and warmer, you have more and more hot days.

Jim Green: Why do you think it's important that NASA is focusing so much energy on climate change right now?

Kate Calvin: So NASA has been doing climate and Earth Science for decades. So they have a decade's long set of data on Earth and atmospheric conditions that give us a sense of both where the Earth is today, but also where we've come from, since we've been doing this for decades. And one of the things you can see from NASA data and others is that climate’s changing. So we just had a release of the update of the temperature record jointly with NOAA, and 2021 was tied for the sixth warmest year on record, and the last eight years are the warmest years on record. And so we're experiencing these more extreme events, and they're going to continue with warming. And NASA has this unique vantage point of space to see the Earth and to be able to provide information that's relevant to decision makers and stakeholders.

Jim Green: Well, tell us about the upcoming NASA climate science activities. I know we've got a bunch of launches. What are you excited about in this area this year?

Kate Calvin: Yeah, we have a lot of launches planned for 2022, I'll just highlight a few. So one of them is the SWOT mission that's coming out towards the end of 2022. This is a satellite that's jointly developed with CNES, the French space agency, with contributions from the UK and Canadian space agencies. And it's focused on measuring oceans and surface water. So it's going to look at lakes and rivers and how rivers flow. And also how oceans are changing. And oceans are really important in climate because they absorb a lot of the heat. So as the Earth warms, the oceans are taking up quite a bit of that. Similarly, they absorb a lot of carbon and SWOT will allow us to better understand the oceans role in a changing climate. 

Kate Calvin: One of the other ones I'm really excited for is an instrument that's going to be launched onto the International Space Station. This is called EMIT and it measures mineral dust from the space station and mineral dust is important both for local climate, but also air quality. So it affects the quality of the air, which has implications for human health and other things.

Jim Green: Well, you know, when I was at Goddard Space Flight Center, and I was working with their climate people, on occasion, what I was seeing coming out of their models, over time, as they added CO2 was changing weather patterns. You know, where areas that were desert was getting more rain, where there were forests, they would become, you know, more arid over time. And so breaking records, temperature records, and looking at those extremes over long periods of time, seems to already give us the idea that the climate is changing. Is that still going on today?

Kate Calvin: Yes, so the climate is changing. We are seeing again, these increases in heat extreme increases in fire weather, which is particularly important in parts of the US. And NASA has a modeling program that does look at, you know, how is this changed in the past and how it might change in the future so that we can better understand those effects going forward. 

Kate Calvin: But I think on your point, it's, you know, climate change is about more than just changes in temperature. There's a whole host of other Earth system changes that come along with this, like changes in the water cycle, which you know, can lead to more floods and more droughts at the same time. And it can lead to changes in our forests and changes in in the whole Earth system. And so that's something that we're looking into both from an observation perspective to understand where we are now and how we got here, but also from a modeling perspective to understand where we might go.

Jim Green: Is there a particular question about our changing climate that you're really interested in answering scientifically?

Kate Calvin: Yeah. So there's a lot of things as a scientist that I'm really interested in the one that sort of stands out for me, has to do with exactly understanding how much the Earth will warm for a given level of emissions. This is something in the science community called climate sensitivity. And we've recently narrowed that range, so we have a better understanding than we did before. Unfortunately, that narrowing is that we've eliminated the possibility of low warming responses. So now we think that the warming for a given emissions level is at least a certain level higher than we thought before. 

Kate Calvin: But really understanding how climate responds to emissions is really important for decision makers as they're planning mitigation actions, but also adaptation. So how much warming might we expect? And how do we respond to that? And so I think the more precise we can give that information, the better it is for people making decisions.

Jim Green: Isn't it also true that there's some climate inertia going on? And maybe that's not the right way to describe it, where, where, even though we may be making progress, and overall reducing our emissions of CO2 and other greenhouse gases, it's gonna take a while for the climate to really respond to that?

Kate Calvin: So warming will stop when we get emissions to what's called net zero, so that effectively any extra carbon dioxide we're putting into the atmosphere, we're also taking out. And at that point, you know, there's some other nuances in that. But that's really that's how you stop warming. 

Kate Calvin: I think you could think of this like a bathtub. And so as long as the faucets on and waters going in, the water level is going to keep going up. If you can turn off that faucet, or balance the water coming in with water you're scooping out, then the water level will stop. And so that's that's where we understand about climate change. So stopping carbon dioxide emissions is a precursor to stopping warming.

Jim Green: ell, you've done a lot of computer modeling studies, I see, about different scenarios in the future, and ways to mitigate these effects of climate change. Tell us about a couple of those that you're especially proud of.

Kate Calvin: Yeah, so one of the highlights for me was this effort I worked on a little more than 10 years ago. For people in the science world, it's called the representative concentration pathways or RCPs. But what these were was a set of scenarios that were really designed to tie together the research community. So there are people out there that look at how do changes in emissions affect climate. There are other people that looked at how you might change emissions, and how does changes in energy affect emissions? There are people that study what the impacts are. So if we have warmer weather, what does that mean for wildfire and heat extremes? What does that mean for food production? And those are all separate groups of researchers. And this project was a way of connecting all of that. 

Jim Green: Have you ever gone out into the field as part of your research?

Kate Calvin: Yeah, I got this opportunity a few years ago. It's not a tradition in the world I come from because we build computer models. So we write code and we stare at computers But one of my co-workers was a forest and soil scientist. And he took me with him to do some field research his area at the time, he was looking at how forests recover after fire. So we spent a week hiking around in measuring trees in Canada. And it was a really, really interesting experience for me both to see where the data that I was using in my model comes from. So I was doing a lot of modeling of forests. And here was an actual forest. And so I could see where are these numbers I'm using coming from. 

Kate Calvin: It was also really useful to see heterogeneity. So not every tree is the same, not every forest is the same. And that's hard to see when you're just looking at a computer. I think it also really gave me an appreciation of satellites. So in one week, the two of us carried covered a very, very small fraction of one part of the world and measured those trees. And if you really want to understand the world's trees, you need to be able to do more and see more. And that's something that satellites give us.

Jim Green: But indeed, that that fieldwork is really critically important because it gives you what we call ground truth, of course. And then you can compare those observations from the ground with those from space and make other inferences.

Kate Calvin: Absolutely, I think the fieldwork in the on the ground research is really important those that understanding the system you're in and that satellites do give us global coverage. After you've done that.

Jim Green: Can you tell us a story about a moment in your work when you had to surmount an obstacle? And what was the challenge and how you overcame it?

Kate Calvin: So a lot of the challenges I’ve faced in my work have to do with communication. So I a lot of my work is very interdisciplinary. I work with physicists, ecologists, economists, chemists. And when you're working across disciplines, one of the challenges comes, are we speaking the same language? And are we doing the things that we intend to do? And so one of the projects I worked on a few years ago, was about linking these two different types of models of the climate system. So one of the parts of the project was about looking at how climate effects land, another part of it was looking at humans might respond to those changes in land. 

Kate Calvin: And we were trying to link information back and forth between them. After a couple of rounds of exchanging information, we started to get some results that were surprising. And when we dug into it a little bit, what we found was that what one model was producing wasn't actually what the other model needed, but we didn't notice it, because we didn't communicate clearly enough when we are setting up this design.

Kate Calvin:  And I've had a lot of variations of this challenge in my career about that. And I think it's pretty natural, different words mean different things to different communities. And the way that we address these sorts of things, is to just keep asking questions to be precise in our language, but also verbose. So not just giving an acronym or a word, but also explaining what that means to us. And so you have to be open to the idea that a word might mean something different to someone else, and really work with them to communicate that clearly.
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #38 dnia: Lipiec 09, 2023, 06:46 »
Gravity Assist: Meet NASA’s New Chief Scientist and Senior Climate Advisor, with Kate Calvin (2)
Jan 28, 2022


Dr. Kate Calvin at the NASA Headquarters Mary W. Jackson building in Washington. Credits: NASA/Bill Ingalls

Jim Green: Well, you know, I have always said, science isn't done until you communicate it. And I mean, between scientists but also the public. What do you think are some of the really big challenges to talk about the current observations and what may evolve with our climate to the public?

Kate Calvin: So some of the challenge, I think with the current observations, it's sometimes it's a little bit easier in the sense that people see that right. So we know that there were wildfires, we see extreme heat events, I think the numbers can get challenging there. So you hear one degree Celsius. And that's hard to interpret. It sounds very small. But really all of these impacts come along with it. And I'd say also on that, since I just said Celsius, depending on the audience you're speaking to, you have to think about units. And so the science community works in metric units. A lot of people in the United States understand Fahrenheit. And so trying to think about that and do that translation, as you're talking is really important. When you're thinking about future. One of the challenges there, I think is that, you know, future warming depends on future emissions. So we can't tell you for sure how warm that will be, in part, because it depends on what happens between now and then. And I think that's a really hard thing to communicate sometimes is that, you know, what we understand what we don't why we don't understand it. And so a lot of this future warming, it's because it depends on our emissions between now and the future.

Jim Green: Well, you've also done some work with the Intergovernmental Panel on Climate Change, or what is commonly called the IPCC. What is that organization? And what does it do?

Kate Calvin: Yeah, so the IPCC is the United Nations body for assessing the state of climate science. The reports are written by scientists, for the IPCC. And they come out every seven or so years, and they assess the state of climate science. So they're not doing new science. They’re looking at all of the peer reviewed publications that have come out in the last decade, and assessing what do we know about climate change, and what don't we? And one of the nice things about the way that the IPCC works is it every sentence that they write has a confident statement. So we can tell you how much do scientists agree on this? How much knowledge do we have in this space? And where do we need more? 

Kate Calvin: The other thing that's really interesting for me about the IPCC, and back to our communication, conversation, is at IPCC, the final summary for policymakers, they're approved word by word by governments and scientists. And so it's, it's an opportunity to really think about how do I communicate my science clearly to someone that needs to use it?

Jim Green: So as chief scientist, you also look over all the other science activity that NASA is doing, what else that we have in our portfolio is exciting you?

Kate Calvin: I'm really excited about the James Webb Space Telescope. I'm sure most people are. So I got up early Christmas morning to watch the launch. And I've been following as it’s unfolded the mirrors and we're expecting first images from it this summer. And so I'm really looking forward to that. I'm also intrigued by the DART mission, which is going to try to change the orbit of an asteroid. And then as someone that you know, watched Apollo 13 as a kid, we have some upcoming robotic and human missions to the Moon under Artemis, that'll be really fun to watch.

Jim Green: Well, I know there's a lot of budding scientists in our audience. And math and computer science is so important. What would you suggest people do to get excited about going into this field?

Kate Calvin: So one of the best pieces of advice I got in grad school was to just take the best opportunity when it comes. So don't try to plan too far ahead, look at what excites you that day, and pursue that. And I think for me, that's what I really been focused on. I started out, I just, I knew I liked math. When I got to undergrad, I decided I liked computer science, too. When I got to grad school that turned into climate science. When I got to my my job, joint Global Change Research Institute, it turned into interdisciplinary science. And now I'm doing science more broadly, not just climate science. And so I think, just follow where it leads and be curious, ask questions. There's no wrong question.

Jim Green: Well, Kate, I always like to ask my guests to tell me what was that person, place, event, or thing that got them so excited about being the scientist they are today. And I call that event a Gravity Assist. So Kate, what was your gravity assist?

Kate Calvin: Yeah, so there's a lot of people that have had an influence on my career. So my high school calculus teachers, the reason I majored in math. My grad school PhD advisor is the reason I do climate. But the person I've been thinking about the most, in the last few weeks since I started at NASA is a guy by the name of Tony Janetos, who was the director of the joint Global Change Research Institute when I started. He was also a former NASA program manager. And at the point where I started at the institute, you know, I was doing climate research, but I was very much engineering-focused. And I worked with a lot of people that were like me, had degrees in my department. And Tony was an ecologist. And he was very much encouraged me to do interdisciplinary research, and to talk to people that had a different perspective than me. And I don't think I'd be where I am today if it weren't for the encouragement that he gave me.

Jim Green: Well, Kate, thanks so much for joining me and talking about this incredibly important topic, and how NASA can play an important role into the future.

Kate Calvin: Thank you so much for having me.

Jim Green: Well join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I'm Jim Green, and this is your Gravity Assist. 


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Jan 28, 2022
Editor: Michael Bock

Source: https://www.nasa.gov/mediacast/gravity-assist-meet-nasa-s-new-chief-scientist-and-senior-climate-advisor-with-kate-calvin
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #39 dnia: Lipiec 16, 2023, 08:54 »
Ziemia monitoruje bez przerwy parametry określające stan ISS.
Rozmowa z kontrolerem lotu z ETHOS (Environmental and Thermal Operating Systems).
Czasem pojawiają się sytuacje awaryjne

https://blogs.nasa.gov/spacestation/tag/mission-control-center/
Cytuj
Sunny Panjwani: So think about, you know, crew needs water to drink, crew needs oxygen to breathe. So we could keep sending oxygen up there. And we could keep sending water up there. But sending things to space is pretty expensive. So we've learned that we can generate water on the space station through byproducts from the crew. So crew members generate three main waste products that I can think of. So, urine is one, you've got sweat whenever they're working out and just moving about the cabin through their work day. And then even when they breathe out, the moisture, the humidity and their breath as they exhale that, we collect all of those, we purify them, and we produce potable drinking water — water, that's honestly a lot cleaner than what comes out of my sink.
Cytuj
So we are there 24/7/365. There's always one person at least on console, monitoring tons of data coming down from all this hardware for you, know, generating the water, generating the oxygen, monitoring all these various systems that we have. So there's always somebody plugged in.

Gravity Assist: In Case of Space Station Emergency, with Sunny Panjwani (1)
Feb 18, 2022


Sunny Panjwani is a flight controller at NASA’s Johnson Space Center in Houston, Texas. Credits: NASA

In space, we have to expect the unexpected. Sunny Panjwani of NASA’s Johnson Space Center shares how he got thrown into an emergency situation on his first day as a flight controller. His team makes sure that astronauts have a safe environment on board the International Space Station. Learn how he got to NASA and how he handles high-pressure circumstances in and out of Mission Control.

Jim Green: For more than 20 years, the International Space Station has been in space with astronauts safely on board.

Jim Green: But what happens if something goes wrong?

Sunny Panjwani: In the training process, as a flight controller, you will go through some pretty rigorous simulations.

Sunny Panjwani: It was just surreal being there my first day and feeling like I was still stuck in a simulation.

Jim Green: Hi, I'm Jim Green. And this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: I'm here with Sunny Panjwani. And he is a flight controller for the International Space Station based out of Johnson Space Center in Houston, Texas. Welcome, Sunny, to Gravity Assist.

Sunny Panjwani: Hey, Jim, thanks. It's great to be here. And I have to say you just made a cool job sound even cooler. So thank you for, for doing it like that.

Jim Green: Oh, my pleasure. I mean, wow, running the entire space station with flight controllers on the ground. It sounds so complicated. But before we talk about that, I really want to know how you got to NASA. And what made you so interested in space?

Sunny Panjwani: Yeah, that's a great question. And I think it always starts off for us, you know, being kids and being interested in something from a young age. And for me, it was always the night sky. That was always like my best friend, it was always that silent observer, that listener for me when I was alone.

Sunny Panjwani: And so I became, you know, kind of obsessed with the night sky and all the things I heard about astronauts doing and people going up there to the Moon and things like that. And, you know, being a kid, I had the whole “shoot for the stars” thing, I took that kind of realistically, and I wanted to be an astronaut, but I also wanted to be a doctor. So I wanted to be a doctor-astronaut. And, you know, someone had told me that some astronauts are doctors, so I believe that and my parents told me, “Hey, you know, shoot a little bit, a little bit lower, but you know, just keep dreaming.” And I said, “Okay, sure.” And I grew up and I thought, Okay, I will be a doctor that works with astronauts. So you know, we also have those at the center called flight surgeons.

Sunny Panjwani: Now, I stayed on that path for a while, you know, through middle school, in high school, like a lot of people, we took medical classes, and I certified to be an EMT. For me, what really changed was: there was a loss in my family when I entered college. My father was, was shot and killed when I was younger.

Jim Green: Oh, I’m so sorry.

Sunny Panjwani: Thank you, I appreciate that. And he was shot and killed at his workplace very suddenly. And that that kind of threw me off my core, so veered off, and I lost hope in myself. And, you know, when that happened, just as for a lot of people, when things like that happen, I just I stopped and just threw everything off to the side and thought, “Hey, I can't chase my dream anymore. I can't keep going in that direction.”

Sunny Panjwani: So I chose something safer. And I'll tell you what I did. I, I started off as a biology major in college that first year, and then after losing my dad, I, the next week, I switched over to accounting, because I thought, “hey, I need a job that puts some, some money on the table.” And Jim, we just met like five minutes ago, and I will tell you, I'm never gonna be that friend that you can call to help with your taxes. (laughs)

Jim Green: (laughs)

Sunny Panjwani: I'm not, I'm not that guy.

Sunny Panjwani: And it was never my love and passion, but I tried staying with it. And you know, people always told me, Sunny, do what gets you through the day, you know, just go and do a degree that will get you a job, do what gets you through the day. And they said, you know, if you'd like biology, if you like science, keep that in, you know, in your back pocket as a minor. So that's exactly what I did. I was the one business major I knew that had a science minor. And, you know, it took a while for me to understand that I didn't want to do what got me through the day, I wanted to chase after what made me want to stay up at night. And that's what so many of us here at NASA do we chase what makes us want to stay up. And so long story short, you know, it took some time, but I think I ended up in the right place.



The International Space Station photographed by Expedition 56 crew members from a Soyuz spacecraft after undocking. Credits: NASA/Roscosmos

Jim Green: That's fantastic. I'm really glad that you did. And I hear that you work in the environmental systems branch of the space station. What does that involve?

Sunny Panjwani: So you know, the environmental and thermal operating systems is a mouthful. So you'll hear me say ETHOS, and that's what the acronym is for that whole thing. So the big part of that, again, like you said, is the Environmental Systems part. So what is that? What does that mean? So let's kind of take it a step back. What do humans need to survive in space? Well, first, you need shelter. So we have the ISS, the actual shell, but you got to pressurize it, you have to have oxygen, you've got to have nitrogen, just like we do here on Earth. And we got to keep those pressures pretty similar to what we have here on Earth. Now, you know, Jim, what's your favorite space movie? Just a personal question.

Jim Green: Oh, “The Martian,” of course.

Sunny Panjwani: Okay. “The Martian,” you know, that's, that's a that's a good one. I think mine has to be Apollo 13. And, okay, Apollo 13. A lot of people can think back and remember the scene where they have to fix their CO2 [carbon dioxide] scrubber because they have a lot of CO2 building up. That's another thing we conquer here at ethos. We're monitoring the CO2 levels, monitoring things like toxins in the air and making sure we're scrubbing that. And then one of the biggest things we do is recycling. And when I say recycling, I'm talking about regenerative life support.

Sunny Panjwani: So think about, you know, crew needs water to drink, crew needs oxygen to breathe. So we could keep sending oxygen up there. And we could keep sending water up there. But sending things to space is pretty expensive. So we've learned that we can generate water on the space station through byproducts from the crew. So crew members generate three main waste products that I can think of. So, urine is one, you've got sweat whenever they're working out and just moving about the cabin through their work day. And then even when they breathe out, the moisture, the humidity and their breath as they exhale that, we collect all of those, we purify them, and we produce potable drinking water — water, that's honestly a lot cleaner than what comes out of my sink.

Sunny Panjwani: So it sounds gross. But I promise I promise it's not that bad. It's, it's very clean water.

Sunny Panjwani: So now that we have this water, we can take that and we can run a current through it — an electrical current —and produce oxygen by splitting the water in half. So the urine, the sweat, the condensate, all of this is being turned into drinkable water and breathable air throughout the day. And that's such an important part of what we do, because that keeps the crew alive and healthy. It keeps costs down. And it makes exploring past, you know, the moon, past Mars one day, hopefully, it makes those things possible.

Jim Green: Yeah, as you say, all that activity is what we would call sustainability. You know, a self-contained environment, you, you manage your waste, minimize that, and use those resources over and over again.

Sunny Panjwani: And I think going back to your, your movie when you said “The Martian,” I mean, that's exactly what he's doing. Right. He's taking his way and making potatoes out of it. And before I have us move on, Jim, I just wanted to mention, the biggest thing we do in ETHOS that I neglected to mention the most important thing, the part of life support that we care about the most is preserving life. So when there's an emergency on the space station, think about a fire, for example, or a rapid depressurization. So let's say you're in an airplane and somebody pokes a hole in the side of it, that air rushing out. That's one of the worst-case scenarios on the space station or a toxic atmosphere. Say there's a gas leak on the space station. When there's an emergency like that, this is the team that leads the crew and leads the rest of the flight control team through that scenario.

Jim Green: Well, in your role, do you often sit at a console and observe what's happening with the incoming data?

Sunny Panjwani: Yeah, and I love these questions, because you gave me a chance to go back to again, my favorite movie. So if you if you think back to Apollo 13, you think back to the the guys in the white shirts and the black ties sitting at consoles, you know, a console is a shorthand for that desk that's surrounded by a bunch of computer screens, and papers, documents everywhere. And that's kind of where we sit day to day when we're on console. Now a lot of work happens in the office, you can say most of the work happens in the office where we have people supporting the people sitting on console that week. But for ETHOS, we are what's called a core console. So we are there 24/7/365. There's always one person at least on console, monitoring tons of data coming down from all this hardware for you, know, generating the water, generating the oxygen, monitoring all these various systems that we have. So there's always somebody plugged in.

Jim Green: So out of your of your group how many are there? And then do you take turns sitting behind the console?

Sunny Panjwani: Yeah, that's a good question. So in our group, we have a few dozen certified flight controllers. And you know, I know that sounds like a lot. But when you think about someone always having to be there, 24/7/365, three shifts a day, it adds up. And it takes a toll on the group. So we have enough to be sustainable, but we're always trying to select more people to become flight controllers and to help plan, train, and fly missions.

Jim Green: Well, what's your day to day activity like? And then what do you do in the office when you're not on console?

Sunny Panjwani: So the day-to-day, let's say I'm walking into console. And actually, that's a great question, because I'm walking into console today after we're done. So you know, we have schedules that are planned out based on people's availability, it's just like any other job, you know, that's the normal part of it. The not=normal part is you're walking into Mission Control. So you're walking past and big doors, you're walking up to the console itself, setting up all your data, your plots, and preparing for the day. And when you're on console, you know, one, you're monitoring all this data coming down. But then you're also planning ahead days ahead, weeks ahead, looking at hey, what's coming three days from now, what's coming six days from now, what's coming a month from now?

Sunny Panjwani: So in the office, when you're not working console, you might be a subject matter expert on some specific piece of hardware for the office. So let's say you're really into that oxygen generator, you know a lot about it. So if there's some kind of new hardware that's flying up that associates with that, that piece of hardware, you might be working with the teams to make sure that all those things are integrated correctly. So really, it's it's a big team effort. And I like to say, none of us is there trying to be the world's best flight controller, we're showing up every day trying to be the world's best flight control team. And that's really what we focus on is the teamwork.

Jim Green: Well, you must prepare for emergency. How are you trained, then, during those times you're not on console? Do you go into a simulator or are you actually walking around something that looks like one of the modules that is attached to Space Station?

Sunny Panjwani: So in the training process, as a flight controller, you will go through some pretty rigorous simulations. So, one, you have all that technical learning, you have to do the book homework, and then you have the actual practice and gaining experience. So you'll walk into a simulator, which is, it's really just a room, it looks just like a flight control room. You're surrounded by all your monitors, all your data is there, your procedures and such. And the data flowing down through all these screens is simulated data based on the software and the hardware you would really have on the space station. So you're getting the same data, except, you know, when you show up for this simulation, it's going to be one of the worst days of your life on console. Because those are the days, those are the days that they really want to prepare you for, and test you, and test you, and break down little bitty things.

Sunny Panjwani: You know, you might have an eight hour simulation, and it was a great sim, but that one part of the sim, that one time you kind of messed up. And that's what they're going to go into at the end of the day, because that's where you can make the improvement. So you know, there's that famous NASA quote that goes, “failure is not an option.” And you know, that might be a great quote, but I would submit that for life and for learning, failure is a requirement. Failure is a prerequisite to success, you know. If we don't fail, if we don't falter, we will never get close to breaking our limits, we won't even get close to our limits. So failure is a big part of the training system.

Jim Green: What kind of emergencies do occur on the ISS?

Sunny Panjwani: My first day on console was last year when I certified to be a back-room flight controller.

Sunny Panjwani: So it was my first day being a co-pilot, basically. And this was the day that the Russian Space Agency was bringing up a vehicle, I'm gonna butcher the name, it's called Nauka, or MLM. And it was an expansion to their space station, their side of the space station.

Sunny Panjwani: Now, sometime after the ship docked about an hour, maybe two hours, all of a sudden, we get a message on the board. And it says loss of attitude control. So attitude control, meaning the positioning of the space station. So that space station was tilting away from its normal position, and we hadn't commanded it to do so, we hadn't told to do so. And then we look up at the screen at these external cameras, and I can see all this ice and debris and dust coming off of the thruster that's now, you know, docked to the space station. So for people who don't kind of, who can't picture this, I want you to imagine going down a highway and I'm in a truck and your car is hitched to my truck, and we're driving down the highway just fine. And all of a sudden you start slamming on the pedal. And now we're veering off in a different direction. And that's exactly what started happening.

Sunny Panjwani: Now the space station did something like one and a half backflips with seven crew inside of it. And it wasn't a rapid spin. But it was a roll. And during that time, my pilot that day was Christopher Brown, just a great flight controller, and he was there to help me and we both talked about, you know, what if the crew has to do an emergency undock. What if there is a rupture in the cabin, what are we looking for? And the data isn't there right now because the space station has veered off of its axis.

Sunny Panjwani: So we're not seeing all this data come down because it's pointed the wrong way. But when it comes back around, we'll get some data. So we're thinking, Okay, let's talk about all the possibilities. What are we looking for? What's the worst case? What's the next worst failure. And of course, we have people from the office tuned in watching this all happen. So we still had support. Now, thankfully, it did stop firing. And we did regain attitude control some time later that day. And the crew was never in any extreme danger.

Sunny Panjwani: But it was just surreal being there my first day and feeling like I was still stuck in a simulation. Snd it really taught me that our training is there, to push us to our limits again, and, and sometimes, you know, you just you're sitting there and you can't believe what's happening, but you're calm, and you're collected, and you're ready to work the problem.
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #40 dnia: Lipiec 16, 2023, 08:55 »
Gravity Assist: In Case of Space Station Emergency, with Sunny Panjwani (2)


Spacewalker Thomas Pesquet of ESA (European Space Agency) waves to the camera 261 miles above Western Sahara as he works to complete the installation of the second roll out solar array on the International Space Station's Port-6 truss structure on June 25, 2021. Flight controllers in Mission Control at NASA’s Johnson Space Center support activities such as this from Mission Control. Credits: NASA/ESA

Jim Green: Well, it sounds like you're prepared for a really high pressured situation, since you were just, you know, thrown right into the mixing bowl on your very first, first day as a as your co-pilot controller. Are these things really, that you learned -- can you apply them to your own life?

Sunny Panjwani: Yeah, and you know, preparing for high stress situations, I learned quickly after I became an EMT after high school and work that job for a little bit. I learned that I need those high-pressure situations a lot of us do because being in a high-pressure environment means that your performance your actions have consequences. And sometimes we need that to drive us forward and to always pay attention to things. So I learned that that's a great fit for me in a job and this job is perfect for that.

Sunny Panjwani: So your question on taking something away, I would have to say, the one thing that I really take away is, is to always play something out to the very end, it's not over until it's over. And especially when the deck is stacked against you. You know that that whole failure is not an option thing. Just keep that in your mind sometimes and keep going, things are gonna keep getting thrown at you, life is gonna put things in your way. But you have to keep going until it's the end, you don't call the ball game you play until the end?

Jim Green: Well, you know, it really sounds like there's always something to learn. And there's always things that could go wrong. And that every day is different. Is that Is that true? And do you really enjoy going into work looking for that next challenge?

Sunny Panjwani: Yeah, absolutely. I think that's one of the great parts of the job is, you know, we do have things in space that are procedural. But with it being a space environment, I wouldn't say that things are routine. There's always variation in things, there's always something that could go wrong. And, of course, we're trying to manage, you know, just basic hardware problems. But we're also trying to make sure that we're not wasting the crew’s time. The crew is up there for six months, usually, and their time is very precious. So we're making sure that they have all all that they need to perform science throughout the day, and that things aren't, you know, giving them hiccups throughout the day and holding them up in places. So we're always just trying to make sure we're in sync with the crew on those things.

Jim Green: Well, I'd be willing to bet most people don't realize how many people are actually in space station at any one time, and that it changes, what's the largest number of astronauts on orbit and in space station at a given time?

Sunny Panjwani: At a given time, you can bet that there are about seven people on the space station. Now, we've had more we've had less. But the six to seven is a the approximate crew complement for any given time. So you know, whenever that space station flies over your house, and it goes around the Earth 16 times a day, there are seven people zooming above your head. And the Space Station has been continuously inhabited for over 20 years. So we've always had at least a person up there and you know, more than one person up there, zipping around the earth for 20 years, which is incredible

Jim Green: Yeah.

Sunny Panjwani: and just a monumental achievement by all the partners.

Jim Green: Yeah, indeed, very much. So we know NASA is planning to send astronauts to the moon through the Artemis program, with a view of someday making it to Mars. Are you involved in any of those activities?

Sunny Panjwani: Well, okay, so I'm a newer flight controller. So I'm not directly involved in the ETHOS group when it comes to the Artemis program. And I love I would love to be in I hope to be one day. But let me let me answer that maybe an analogous way. So if if you think about the ISS as a testbed for taking us further, the ISS is kind of like our training field, right. This is where we plan train and fly to currently, and we're going to the ISS so we can learn about how we can go farther. So we've been to the Moon before, that's a ball game that we've won before. And we're trying to make the Moon the next practice field. And once that's our practice field, and we get good at that, then hopefully we can go to Mars, and that's the Superbowl right? So you know, everything we do day to day, is trying to help us get to that Super Bowl and make that a reality.

Jim Green  33:42

Well, of course, what NASA is doing over the next several years is building an infrastructure at the Moon. And the big infrastructure is called the Gateway.

Sunny Panjwani: That's right.

Jim Green: Of course, astronauts will be in the Gateway. And they'll be performing different types of experiments and all kinds of things in addition to living in the Gateway. And it's from the Gateway that they'll land on the surface of the moon, and then go back to the Gateway. And so you know, controllers are going to be involved in that perhaps that will be your next big step.

Sunny Panjwani: I can only hope so. That sounds incredible.

Jim Green: Yeah, it sounds like fun to me too. Well, what advice would you offer a young person who wants to go into a job like yours?

Sunny Panjwani: Oh, man, I get this one so often. And I I'm never prepared for the answer because I feel like a young guy who just kind of lucked out being you know, here and living my dream day to day. I would say the one thing to take away is serendipity. And I mean, serendipity surrounds us day to day, just chance and you know, sometimes we think about things just falling into place. I would argue that, you know, you have to be the right person in the right place at the right time. And of course for the right thing.

Sunny Panjwani: The one thing that's always going to be in your control is being the right person. So do what it takes to be prepared when that opportunity shows up at your doorstep. So you know, get the degree that you need to make sure you have the experience that would help you be a good team member learn how to communicate professionally, things like that. So become the right person. And when the right place and the right time are there, you'll be the right person for those.

Jim Green: Yeah, that sounds like a good set of advice. Well, Sunny, I always like to ask my guests to tell me, what was the event or person place or thing that got them so excited about being the engineer and the flight controller they are today. And I call that event a gravity assist. So Sunny, what was your gravity assist?

Sunny Panjwani: I love that name. Jim, I knew you were going to ask you this question, because I've heard your podcast, which by the way, love the podcast.

Jim Green: Thank you.

Sunny Panjwani: And so I kind of thought about this question. And the best answer I can give is that my gravity assist has been my family, both the one that I was born into, and the one that I've been so lucky to cultivate through my life. You know, I told you, I changed my major to accounting, and then I switched back to biology. You know, I changed that back to biology three and a half years into college, I changed back to biology because I couldn't sleep at night, and I wanted to chase what kept me up. And before that, you know, I was like, well, if I go back to biology, I don't know what I can do with that degree, because medical school is still too expensive. And I didn't want to take the time away from my family after losing my father, and I would have to go home, once I switched my degree back to bio. And my mom would be there and she would ask me at night, you know, I'd come home from college, on those weekends. And she'd say, “Hey, so how are things going?” And then she would eventually ask, you know, “So do you know what you want to do yet?” And it would break my heart because I would have to look at her and say, “No, I, I still don't know what I want to do. “

Sunny Panjwani: And, you know, to her credit, being the person she is She took my hand every time and she said, you'll find it. You just keep going, you know, your dad and I are with you, and you'll find it. And before that when I was last that I was working, you know, a hotel job while I was in community college, before I'd even gone to a major university, I met a person named Sherry, who's part of my family now. And she was just a guest who was checking into the hotel during this big NASA conference. And, you know, I was a business major at the time. So I was very geeked out talking to all these people. And she struck a conversation up with me that week.

Sunny Panjwani: And she took an interest in me and she extended her hand and you know, a person she'd never known, never owed anything to, and told me to keep in contact. And she said, you know, don't give up on your dream so soon. You deserve to chase your dreams. And even when I showed up at NASA as an intern, after she convinced me to apply, and after I showed up as an intern, the team that I was working with saw that I had this crippling imposter syndrome that you know, a lot of us carry here at NASA. Working in one of the greatest places to be in the world kind of comes with that imposter syndrome sometimes, and they saw that I had that. And my mentors, Brian and David, they, they took my hand, a kid who had no research experience, who had no background for his degree, and they said, “We trust you, you know, keep pushing.” And they pushed me forward. And so my family has been my gravity assist. And every day I walk into work, and I see all those partner flags for the International Space Station, and I see that mission control patch, and the flight ops patch, I think of all those people, and without all those people, I wouldn't be where I am today.

Jim Green: Well, that's fantastic, Sunny, I really appreciate having the time talking to you about controlling Space Station. And I'm really delighted that you're behind the console. I would feel comfortable if I was an astronaut living in working on Space Station, and then having you work with me when I go to the Gateway and then to the Moon. All right? Let's do that.

Sunny Panjwani: Yeah. Well, I hope I hope we can send you there, Jim.

Jim Green: Well, join me next time as we continue our journey to look under the hood at NASA and see what we do and how we do it. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Feb 18, 2022
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-in-case-of-space-station-emergency-with-sunny-panjwani
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #41 dnia: Lipiec 23, 2023, 15:15 »
Dr Aaron Yung, astrofizyk z Goddard Space Flight Center przedstawia oczekiwania związane z obserwacjami JWST.
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Aaron Yung: Spoiler alert there, we’re waiting for the JWST images. So something we know for sure is that they are going to be really red. And they are also likely to be irregular in shape, because spiral galaxies take several mergers to merge, and they're usually bigger. But these early galaxies, they’re so red, and we are going to see them in infrared, because you see, we expect these galaxies to emit a lot of ultraviolet light. But because this light traveled a long way to get to us, and along its long journey, the light wave has been stretched so much that it becomes infrared. And Webb is designed specifically to detect light in this regime. And we also expect these galaxies to be smaller than the ones we saw in a nearby Universe. Because there was so little time has elapsed after the Big Bang, they don't really have a lot of time to evolve, to grow mass yet. But they're also expected to be brighter than the nearby galaxies of similar mass, because they're full of young stars and young stellar populations are expected to be significantly brighter than older populations.

Gravity Assist: Using Webb to Trace Galactic Histories, with Aaron Yung (1)
Mar 4, 2022


To help scientists predict what the James Webb Space Telescope will see, Aaron Yung at NASA’s Goddard Space Flight Center creates simulations of galaxies in the early universe. At left, an Ultra-Deep Field image from the Hubble Space Telescope; middle, a simulation of Hubble’s view; right, a simulation of what Webb will see.  Credits: Yung et al.

Learn more about these simulations at the Webb blog

The James Webb Space Telescope, which launched Dec. 25, will allow us to see the farthest galaxies and better understand the origins of the Milky Way. Aaron Yung at NASA’s Goddard Space Flight Center is preparing for these historic observations by simulating what Webb will see in the early universe. But Aaron’s path to mind-bending research wasn’t easy. When he came to the United States as a teenager, he spoke a different native language and didn’t have the preparation other kids had for math and physics. Learn about Aaron’s journey in this episode of Gravity Assist.

Jim Green: Our new James Webb Space Telescope is a time machine, observing the early stars and gas that make up the early universe.

Aaron Yung: By looking at galaxies from far away to nearby, we can put together the universe’s evolution history.

Jim Green: Hi, I'm Jim Green. And this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: I'm here with Dr. Aaron Yung, and he is a NASA postdoctoral fellow at Goddard Space Flight Center in Greenbelt, Maryland. Aaron has been working on a variety of projects related to how the James Webb Space Telescope will study the early universe. James Webb is of course, our most powerful infrared space telescope we've ever launched. It will start groundbreaking science later this year with its first observations coming up. So welcome, Aaron, to Gravity Assist.

Aaron Yung: Thank you for having me, Jim.

Jim Green: Well, I'm just delighted to talk to you because James Webb has such a spectacular telescope. And as we talk, they're going through their calibration and aligning the mirrors. And I can't wait for those first observations. So how did you get involved with NASA and the Webb telescope?

Aaron Yung: So my background is actually in theoretical astrophysics. And I specialize in modeling galaxy formation. So my work is all about understanding the physics that drives the formation and evolution of galaxies, especially the ones that form in the very early universe, and the way they evolved and interact with the cosmos. So these studies are the key to answering big open questions like how the universe works,  and how did we get here. You can see that these questions align very well with the mission of the James Webb Space Telescope. So in anticipation of our next great observatory, I did a dissertation on making predictions for galaxies in the early universe, which JWST will help us see for the first time, and I call this work semi-analytic forecasts for JWST. I use theoretical models to predict what JWST will see in galaxy surveys. And this simulated data helps optimize the way we look for galaxies.

Aaron Yung: It also helps interpret and understand the galaxies we see. So right after I received my Ph.D. from Rutgers University in 2020, I joined Goddard Space Flight Center as a JWST fellow through the NASA postdoctoral program. And the position allows me to continue working with observing teams, which I provide theory support for future JWST observations. And I also get to continue my work on creating forecasts for other flagship telescopes.

Jim Green: That's fantastic. So that early work you did in your thesis is really what got you the attention of NASA. And then, you know, we just had to have you on the team.

Jim Green: But why do we care about the early galaxy formations?

Aaron Yung: So before we talk about early galaxies, we need to talk about the time machine aspect of JWST. You see, because light travels at a finite speed. So we have light from different parts of the universe constantly streaming to us, since this light carries information about the universe at the time it was emitted. So the longer the light has traveled, the older the information is, and is therefore showing us what the universe was like further back in time. So by looking at galaxies from far away to nearby, we can put together the universe’s evolution history.



Postdoctoral fellow Aaron Yung, at right, with NASA Gravity Assist host Jim Green. Credits: Aaron Yung

Aaron Yung: So now why do we care? Because in addition to living on the planet, and in a solar system, we also live inside a very big galaxy. And naturally, we are curious about its history. Current theory says that galaxy formed hierarchically, starting with the small ones, and then later [they] grow bigger through mergers and accretion. And we think our Milky Way galaxy went through the same process. So these first galaxies that JWST will see, are not the progenitor of our own Milky Way. But looking at these galaxies, we can get a sense of what universe was like in the past. And that will give us clues about what our Milky Way galaxy has undergone in the past.

Jim Green: So Aaron, based on what we think we know, there's a start of the universe called the big bang. And then after that, what happens?

Aaron Yung: So by measuring how fast the universe expands, we think the Big Bang happened about 13.8 billion years ago. And that was the beginning of the universe’s timeline. So after that the universe [has] undergone some violent expansion, and then the content of the universe gradually cooled. And then at some point, baryonic matter can exist.

Aaron Yung: So this baryonic matters are the things that made up of stars and galaxies and you and me. So after these baryonic matter forms, they will have to gradually coagulate under the effects of gravity. And then we experienced a phase of the universe that we call the dark age. So galaxies kind of formed, but we can't really see them because they're obscured or blocked by neutral gas. But over time, when galaxies start to pump out radiations to the universe, to the intergalactic medium, so space between galaxies, the universe gradually becomes ionized, or, in other words becomes transparent. So light can travel freely through the universe, and now we can see the universe clearly.

Jim Green: Okay, so after the Big Bang, we get a time period where matter starts forming into stars, and then stars and dust and galaxies are formed from that. And, of course, what happens later, our solar systems are made around stars. In fact, our solar system is only 4.6 billion years old. So this big bang happened a long time ago.

Jim Green: Well, how do we define a galaxy? Is it made up of a certain number of stars? Is there a limit?

Aaron Yung: So galaxies are actually more than stars. There's also gas in there, multi-phase gas, hot and cold and ionized. And also they interact with their own dark matter halo. And when galaxies form in a cluster, they also interact with their neighbors. So there are all sorts of things going on, and there's not really a limit on how many stars there need to be to become a galaxy.

Jim Green: Well, what do we think these are early galaxies look like? Do they start out being spiral galaxies right away?

Aaron Yung: Spoiler alert there, we’re waiting for the JWST images. So something we know for sure is that they are going to be really red. And they are also likely to be irregular in shape, because spiral galaxies take several mergers to merge, and they're usually bigger. But these early galaxies, they’re so red, and we are going to see them in infrared, because you see, we expect these galaxies to emit a lot of ultraviolet light. But because this light traveled a long way to get to us, and along its long journey, the light wave has been stretched so much that it becomes infrared. And Webb is designed specifically to detect light in this regime. And we also expect these galaxies to be smaller than the ones we saw in a nearby Universe. Because there was so little time has elapsed after the Big Bang, they don't really have a lot of time to evolve, to grow mass yet. But they're also expected to be brighter than the nearby galaxies of similar mass, because they're full of young stars and young stellar populations are expected to be significantly brighter than older populations.

Jim Green: So those young stars, do they get really massive and, and do we see stars today that big? Or are they something special to behold?

Aaron Yung: They are likely to be even more massive than the stars we have today because when the universe starts off, there isn't really a lot of heavy elements. So we expected these stars formed out of gas that are pristine from the Big Bang, and because they don't really have metal in them. So the gases are cooling very inefficiently. And that will lead to the formation of bigger stars. So they tend to be brighter, but they also burn up their fuel faster. And that plays a role into why the younger stellar populations is brighter, because they contain more of this massive but short-lived stars. And when the stellar population grow old, these young stars star to die out. And the older, longer lasting stars are intrinsically less bright. And that's why.

Jim Green: Ah, so that's why we want to go back in time and look at these early galaxies, because the primary stars that make them up are so different than the kind of stars that we have today, particularly the typical ones. So this is really an exciting opportunity for us to really tease out that early phase of the evolution of the solar system and our stars and other galaxies. Well, what are the features of the Webb observatory that really allow you to study this early universe?

Aaron Yung: So there's so many things that went into the design of JWST that makes it the greatest of all time for studying the early universe. And here, let me just highlight a few.

Aaron Yung: First, JWST's iconic primary mirror is extremely large. It is 6.5 meters across, and its area is nearly seven times bigger than Hubble. The large mirror will help collect more light and give us a chance to detect the sources that are extremely distant and faint. And since Webb will observe the universe, in infrared, the mirror is coated with a thin layer of gold, which is the best material for reflecting infrared. And since everything with the temperature glows in infrared, it is important to keep the telescope’s optical components and scientific instruments cool, like really, really cool.

Aaron Yung: So instead of orbiting Earth like Hubble does, Webb is at an orbit 1 million miles away from us, and to keep it cool from the Sun's radiation, Webb is also equipped with a sunshield that is the size of a tennis court. And that will keep Webb at its operating temperature of 50 Kelvin, or negative 370 degrees Fahrenheit. And the mid-infrared instrument has its own cryogenic cooler that cools it even further to below 6 Kelvin, or negative 449 degrees Fahrenheit.

Aaron Yung: So both the big mirror and the low operating temperature are required for the extremely sensitive scientific instruments to operate. These instruments will process the light that reaches us and turn them into images or spectra, and through them, we will be able to see the early universe.

Jim Green: Well, you know, Aaron, a lot of people know a lot about the Hubble Space Telescope. And now we have the JWST telescope almost operational. What's going to be the major differences that we will have from the observations that these two spacecraft make?

Aaron Yung: So one that JWST is going to be 100 times more sensitive than Hubble. So it will be able to detect galaxies that are fainter than what Hubble can see. And that will show us galaxies are also further out, forming at even earlier times. So that is very exciting. And additionally, JWST also has additional mid-infrared capability that Hubble doesn't have. So that will help us see other things like stars behind the cloud of dust, or AGN that are obscured by its host galaxies.

Jim Green: Aaron, do the early galaxies have black holes? Or are they formed later?

Aaron Yung: Indeed, we think there will be black holes in them. So the current theory is that there could be some supermassive black hole seeds that are left behind by the very first stars. So these black hole seeds will sit there quietly as the galaxy forms. So they might not have a strong effect on the galaxies. But over time when they grow in mass, and they start accreting, they can indeed affect their host galaxies. So besides supporting JWST observations, I'm also the PI of a JWST cycle I theory program, which I will be developing a theoretical framework to explore the symbiotic relation between the early forming black holes and their host galaxies. So when a black hole accretes matter rapidly, you can have strong impact on their host galaxies in many ways. However, the black holes themselves are probably obscured by their host galaxies. So even with JWST, we might not be able to see them directly. So my theoretical framework will tie this early forming black holes to the properties of their host galaxies, and suggests ways that we can probe them indirectly through signals that are observable by JWST.

Jim Green: Yeah, that's fantastic. What do you expect, then, to see, to verify your simulations? Will that come in one image or a series of images or are all the images have to be put together before you see the early universe?

Aaron Yung: So that will have to wait until the exciting JWST program to happen. So it's unlikely to be one single image, but it's probably a mosaic of images that we get from a large JWST survey.

Aaron Yung: We already have several programs that are planned to do deep galaxy surveys within the first year of operation.
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #42 dnia: Lipiec 23, 2023, 15:15 »
Gravity Assist: Using Webb to Trace Galactic Histories, with Aaron Yung (2)


Aaron Yung simulates the early universe at NASA’s Goddard Space Flight Center. Credits: Aaron Yung

Jim Green: Well, what is Webb doing right now? What's been going on since it was launched?

Aaron Yung: Right. Since the big launch a little under two months ago, JWST has undergone a series of delicate steps to unfold itself. So remember that gigantic mirror and sunshield that I mentioned, the whole telescope is so big that it must be folded up to fit inside the rocket that launches it to space. In the first two weeks of its journey, we saw successful deployment of everything. So big kudos to all the engineers who design and build the telescope.

Aaron Yung: JWST was then successfully inserted into his target orbits the second Lagrangian point, and would go through a six month long commissioning process. So right now, the team at the JWST Mission Control Center in Maryland, is working on aligning the 18 segments of the primary mirror. At [the] start, each segment is kind of doing its own thing. And the goal is to make all of the segments work coherently as one giant mirror. So right now, Webb is looking at a bright star, but 18 different bright dots show up in the detector. The team needs to first identify which dot corresponds to which segment, and then the mirror segments will need to be moved and individually adjusted. And at the end, they will move the mirror once again to stack the 18 images to make all the segments work as one. So we got to be patient.

Jim Green: Well, did you always want to be a scientist?

Aaron Yung: Well, the answer is a bit, a yes and no. I always have a thing for physics, but never had the confidence to make it my career. I remember when I was little at an age when I was still building towers and bridges with wooden blocks, I became aware of the invisible rules that all my toys seem to follow, you know, the way things fall, the way certain things bounce after falling, or colliding, or the trajectory of [a] baseball, that sort of thing. I was really curious about the kinds of rules that are sort of behind the scenes. And to see if I got them right, I actually emulate[d] things in my head, like imagine a tower blocks, and you give it a little push in your head and you can, you can use your imagination to follow the cascade of the blocks. And that was really fantastic for a kid who had to wait to see the doctor all the time.

Aaron Yung: And I, I wanted to learn more. So later I learned that these rules are called physics. And it wasn't the English word physics, but the Chinese phrase for physics, which is made up of two words: matter and logic. So together, they spell “making sense of things.” And that idea kind of stuck with me.

Aaron Yung: So fast forward a decade, I immigrated to the United States with my family when I was 15. And I grew up in Hawaii. So that was fun. But at the beginning, it was pretty rough, because I had to catch up with the language. I started high school in the last month of ninth grade. So I practically missed a whole year of high school. And I needed to catch up with the credits. So I was catching up so hard that I took extra classes before school, after school, online and over the summer. I graduated high school a whole year earlier. But I didn't have a chance to take any advanced physics and math classes. So I wasn't prepared to take physics. And I actually started college as a finance major. But a year later, I decided to switch majors to physics. I went back to tell my high school physics teacher about it. And she wasn't exactly encouraging. Well, maybe she knew I wasn't prepared for that.

Aaron Yung: Everyone told me physics is hard, and you need to be really good at math to get in. And that's why I never had the confidence to even consider doing it for my career. And to be fair, I say that sort of things too, sometimes. So maybe there is some truth to it. But would I add a little twist to it. Instead of saying that, I should say, “If you do physics, you will need a lot of math. But no matter where you are at now, you will need to work your hardest, and get used to learning things on the fly. So as long as you have the strength to persevere, you will be fine.”

Jim Green: Yeah, that's really a good philosophy. You know, and I have a little modification, if I may, that I say in the same way you do. And that is all math is not created equal. I really enjoyed various types of math, but not everything. For instance, I was horrible in geometry. But I did not let that stop me going on, completing a variety of math and physics courses. So indeed, it's really about determination, and being able to enjoy what you're doing.

Jim Green: Well, Aaron, I always like to ask my guests to tell me what was that event or person place or thing that got them so excited about being a scientist that they are today? I call that event a gravity assist. So Aaron, what was your gravity assist?

Aaron Yung: So like the Voyager missions, I actually had several and I will limit myself to just three. So the first gravity assist that changed my life trajectory happened in my undergrad. At first I wanted to do research in mathematical physics, but I was turned down by the person who I wanted to work with. And the astronomy professor next door took me in, her name is Aparna Venkatesan. She talked me into her research group and brought astronomy in to my life. So as an undergrad working with her, I also got to observe at the Arecibo Observatory at Puerto Rico, which was my first experience working with a big telescope. So the next one I had. And also, the biggest one I had so far is from my thesis advisor, Rachel Somerville, her life research launched in my whole career and gave me the necessary acceleration towards working on theoretical astrophysics and working with JWST.

Aaron Yung: And finally, NASA, the one that I'm experiencing right now, NASA took me in at a time when the field was still quite uncertain about when JWST would be launched. So joining NASA and having direct access to the people that work closely with JWST, and the Roman Space Telescope is really setting me up to continue developing all the work, I have started and get inspired to take this work to new directions. And here is a bonus one. Since I joined NASA during the early phase of the pandemic, I've spent most of my time working remotely. And that took a toll on experience working as a part of the agency. So the silver lining is that we're spending more time online. And I ran into you, Jim. So, Jim and I met through social media about a year ago. And since then, we have been working together on two weekly shows that we engage with a live public audience. And we talk about literally everything on astronomy and space exploration. So I obviously enjoyed my front row seat to all your exciting stories on Mars exploration, planetary science, and countless NASA missions and histories. But I also feel incredibly privileged working with you in this capacity. So thank you for all the science communication training, and being my role model for making science accessible.

Jim Green: Well, that was really kind of you to say Aaron, and and I have to say, I've really enjoyed working with you, when we get together and talk on Clubhouse. Indeed, it's it's wonderful to have many different people from many different walks of life, around the world, sitting in listening to us talk about science, and then allowing them to ask us some really great and penetrating questions. So Aaron, thanks so much for joining me on Gravity Assist in talking about the fantastic things that you're doing, modeling all those early galaxies, waiting for JWST data to come in.

Aaron Yung: Thank you, Jim.

Jim Green: Well join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Mar 4, 2022
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-using-webb-to-trace-galactic-histories-with-aaron-yung
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #43 dnia: Lipiec 30, 2023, 08:23 »
Czy meteoryty mogą pochodzić z Merkurego?
Cytuj
Neyda Abreu: So there have been some people who have suggested that some rocks that we have in a meteorite collection might come from Mercury. That is a difficult question to answer, right. And one of the obstacles that we run into when we think about how a rock from Mercury might have made it into Earth is that the Sun is the 10 to the 30 kilogram gorilla in this solar system, and that it's a very large gravity well, and getting that rock from that interior region of the solar system into Earth would be difficult. Now, there are still some open discussion as to whether some samples might come from Mercury.

Gravity Assist: These Space Rocks Have Seen It All, with Neyda Abreu (1)
Mar 18, 2022


Blue ice field in the Miller Range, near the edge of a moraine, in Antarctica. Moraines are piles of rocks deposited along the edge of a glacier. Often they are good hunting grounds for meteorites, but the samples from space are mixed in with lots of terrestrial rocks. Credits: NASA/Cindy Evans

How do we know if a rock came from the Moon, Mars, or an asteroid? Planetary scientist Neyda Abreu has looked inside all kinds of meteorites to understand where they came from and what’s inside them. She also traveled to Antarctica to hunt for space rock treasure. Since she was a child in Venezuela, she has been curious about the life cycles of stars and planets. Learn about her work with meteorites and her journey to become a scientist. 

Jim Green: Small pieces of the earliest rock fall on the Earth every day. How do we find them? And what can they tell us about the makeup of our planet? And perhaps how life started on Earth?

Jim Green: Hi, I'm Jim Green. And this Gravity Assist, NASA’s interplanetary talk show. We’re going to explore the inside workings of NASA and meet fascinating people who make space missions happen.

Jim Green: I'm here with Dr. Neyda Abreu. And she's a planetary scientist, and the senior advisor for science and research at NASA's Langley Research Center. Welcome, Neyda, to Gravity Assist.

Neyda Abreu: I'm thrilled to be here. Thank you so much for the invitation. And thank you for having me.

Jim Green: My pleasure. Now, I understand that you've been involved in studying meteorites, what are meteorites?

Neyda Abreu: The most simplified way to explain it is rocks from space. Now, I think it was Muriel Rukeyser, who said that the universe is made out of stories, not of atoms. And if that's the case, then meteorites are some of the most interesting storytellers that you can imagine. They have been in the right places at the right times. And one of the things that really excited me about being able to look at these samples was the ability to piece together these stories of the solar system by understanding what had happened to these rocks.

Neyda Abreu: And they rain on us, so they make it easy on us to be able to ask those questions and to be able to see how these very small samples sometimes can tell us about very large processes, and how they can tell us about things that have happened over periods of times that are incredibly extensive.

Jim Green: Well, what originally got you interested in studying meteorites?

Neyda Abreu: So I was interested in origins of the solar system for quite a long time. I, as I said, I like stories. And this is, in some ways, the grandest story that you can probably tell.

Neyda Abreu: Well, I grew up in the Venezuelan Andes. And that's very north of South America. And there's some big mountains. And one of the nice things about being high up is there were some very nice telescopes. Some of the few equatorial latitude telescopes were located in my hometown. So that attracted me to going into astronomy as well. And eventually, I decided to come to the US to continue my studies. So when I was, I believe, 17, I came to Minnesota, I went to the University of Minnesota, and had a really fantastic opportunity to do my undergraduate in physics and astronomy.

Neyda Abreu: And then I realized that I wanted to have something tangible. And in some ways, being able to have this artifact, this piece of solar system history in my hands on my desk, being able to go back to the lab all the time and be able to look at these samples, sometimes I was the first person looking at some of these samples, [it] was extremely exciting.

Jim Green: Well, what kind of meteorites do we know about?



Neyda Abreu, senior advisor for science and research at NASA's Langley Research Center, on a meteorite-collecting trip in Antarctica.  Credits: Neyda Abreu/Antarctic Search for Meteorites

Neyda Abreu: There’s a variety of different types, but at the largest scale, you can subdivide them in different ways. One way in which I like to think about them is there's meteorites that come from asteroids. So those are small, planet like bodies. Then there's meteorites that come from the Moon. And then there's meteorites that come from Mars. Other like other people like to think about them in terms of what they're made out of. So some, some of them think about them in terms of meteorites that are mainly made out of metals. They're ones that have some metal and some rocky components, silicate components inside of them, and some of them that are mostly rocky silicates. So there's ways in which you can cut the different types of meteorites depending on how you want to tell the story.

Jim Green: Well, how these meteorites that that you call metals, how do they form that way?

Neyda Abreu: So this is one of those very fascinating things about meteorites, and that is that some of asteroidal meteorites, the one that comes from these planetesimals, can come from different parts of an asteroid, right? So asteroids are traveling around, that's how we get meteorites here. And they collide with one another, as they collide with one another, they can break up and sometimes parts of the asteroid can be exposed that they normally wouldn't, and that they would normally not be available from very large bodies like the Earth or Mars or the Moon. So we can get pieces from the interior, from the metal rich-core of planets and being able to understand also processes that may be happening in other terrestrial planets, terrestrial planets are the rocky ones in the inside of the solar system. And we wouldn't be able to get any direct confirmation to our theories and our understanding of the interior of planets without having access to the interior of asteroids. So they're very exciting.

Jim Green: Well, you know, I have heard that maybe as much as 100 tons of meteoritic material fall on the Earth every day. I mean, that sounds like we ought to be able to walk outside our door and pick up a rock and say, hey, this rock came from space!

Neyda Abreu: And every once in a while people can do that. (laughs)

Jim Green: Yeah. Wow! So what are what should we be looking for? What are those features that make a meteoric rock look so different than the rocks here on Earth?

Neyda Abreu: Well, that's one of the hard parts. So in particular, for these meteorites that come from the Moon or come from Mars, they can be very similar to rocks that are part of our planet. Sometimes, even when we are actually looking for meteorites, and are out there specifically thinking about wanting to find meteorites, it can be difficult to tell them apart from terrestrial rocks. However, there is one thing that is very helpful, and that thing is the fusion crust.

Neyda Abreu: So before it becomes a meteorite, a rock that is crossing the atmosphere is called a meteor at and it interacts with the terrestrial atmosphere. So what happens is that most of the material that really is in contact with the atmosphere gets ablated. Basically, we lose it due to the interaction between the atmosphere and the meteorite. But there is a thin rind of this darkened material that is called a fusion crust, and it's very thin, you wouldn't be expecting anything that is like an inch thick. It's more like a fingernail thick. And it's dark. And in many cases, it can be continuous around the whole sample. So that is one of the ways to tell. It is also possible that some meteorites contain quite a bit of magnetic metal in them. Not every rock that attaches to a magnet is a meteorite. But many meteorites do (laughs) do attract a magnet. So it's more like accumulating a variety of different characteristics before you can definitely tell whether or not that's a meteorite.

Jim Green: So in 2013, one of the most spectacular meteorite falls happened in Russia in Chelyabinsk.

Jim Green: Well, a friend of mine sent me a piece of Chelyabinsk. And what I what I really enjoy about it, indeed, is that black fusion crossed over part of it. And that's, as you say, was exposed to the atmosphere. It literally melted rock. But inside it when I look, I don't see a uniform color. I see different types of, of colors, in terms of gray and, and not so gray and even white. What are those things?

Neyda Abreu: So it really depends on the meteorite, right. So in a meteorite that comes from Mars, or come from the moon, it would be minerals that are typically found in igneous rocks. When you move to asteroidal meteorites you can get a variety of other types of minerals. So if you were to look at, for example, some of the these meteorites that contain a lot of iron and not a lot of nickel, then you would get these iron nickel alloys. And if you were to actually polish that surface, you would get these incredibly intricate patterns. So that would be very different from a meteorite that came from Mars or the Moon. And then the asteroidal meteorites that come from bodies that never had that core-mantle-crust structure, will have a very different assortment of minerals as well.

Jim Green: So the accumulation of these minerals make up the different colors.

Neyda Abreu: Mhm.

Jim Green: Well, that's fascinating when you think about it. But I heard you also have been on a variety of expeditions to look for them. So does that mean you just get into a field and walk across looking for meteorites?

Neyda Abreu: In certain parts of the planet, that is actually a possibility. (laughs) And one of the most striking places to do that is Antarctica.

Jim Green: Wow. Antarctica! Why there?

Neyda Abreu: Why there? Well, for one thing, it's easy, right? You have an immense amount of ice, and you have black rocks on top of it. In certain parts of the ice, that's all the rocks that you get. So it's extremely easy. You go out, you see something black, that's a meteorite. It's not always that easy to find meteorites in in Antarctica, but in the ideal world, it is. So yeah, pretty spectacular place.

Jim Green: So what happens then is a group or a team will go down to Antarctica and get into snowmobiles, and then cruise across these glaciers looking for the black rocks. So how many expeditions like that have you been on?

Neyda Abreu: Just the once. And I have to say, can you imagine anything more fun than doing that?

Jim Green: (laughs)

Jim Green: Yeah, riding snowmobiles in the snow looking for meteorites. I understand that would be a blast. How long were you there? And then how many meteorites did you bring back?

Neyda Abreu: Oh, my God, we got so extremely lucky in my one season in Antarctica. So altogether, you have to spend some time ahead of time in Antarctica in a station called McMurdo, getting ready, getting trained grant getting supplies. So that took a couple weeks. Then we spent, I think it was about seven weeks, living in tents in the Transantarctic Mountains. And then we had to come back and pack everything that had been used and the meteorites make sure that everything was safe. So all together, it was a bit over two months.
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Odp: [NASA Gravity Assist] : Season 5
« Odpowiedź #44 dnia: Lipiec 30, 2023, 08:23 »
Gravity Assist: These Space Rocks Have Seen It All, with Neyda Abreu (2)
Mar 18, 2022


Planetary scientist Neyda Abreu visited Antarctica during a two-month fieldtrip in 2009 to 2010 to collect meteorites
Credits: Neyda Abreu/Antarctic Search for Meteorites


Jim Green: So what happened during that time period for celebrating the holidays?

Neyda Abreu: Oh, my goodness, we had such a fantastic winter holiday celebrations on the ice. We had really good weather. So we were able to have an outdoors, December 25th dinner, and we were able to take the covers of the snowmobile. you get all of this ice drifting towards them. So you don't want for them to accumulate all the ice. So you put these covers on top of them. But we were able to repurpose those covers to make a tablecloth. So we had a bunch of buckets, tablecloths from the snowmobile(s).   

Neyda Abreu: And we had a little oven. It was a very small oven. But we could use that to make our dinner, to make our turkey. And then we were very excited. We had everything set up for the outdoors part of the dinner. But we forgot that thawing a turkey in the field in Antarctica might be a tad of a challenge. So part of our team just decided we're gonna do this. We're gonna do this no matter what. So we have this monster thing. Tried to put it in the oven. There's no way. The turkey is much bigger than the oven. So there had to be a way to take this thing apart. And some of our teammates took a chainsaw to cut the turkey. So I do not know of another Christmas dinner celebration involving a chainsaw preparation of a turkey.

Jim Green: (laughs) You know, as you're saying this, I was thinking, well, if you're going to defrost the turkey, maybe everybody would have to take turns holding it, you know, trying to defrost it. But the chainsaw is much better way. (laughs)

Jim Green: And how many meteorites did you find? Do you remember?

Neyda Abreu: Yes, we went over the thousand individual samples.

Jim Green: Wow, that was a good season. Yeah.

Jim Green: So when we look through our collection, and we find perhaps, something from Mars, and perhaps something from the moon, are we also looking for rocks from Venus or other bodies in the solar system? And do we find them?

Neyda Abreu: So there have been some people who have suggested that some rocks that we have in a meteorite collection might come from Mercury. That is a difficult question to answer, right. And one of the obstacles that we run into when we think about how a rock from Mercury might have made it into Earth is that the Sun is the 10 to the 30 kilogram gorilla in this solar system, and that it's a very large gravity well, and getting that rock from that interior region of the solar system into Earth would be difficult. Now, there are still some open discussion as to whether some samples might come from Mercury.

Neyda Abreu: Venus is not as close to the sun, but it has its own set of challenges. We actually don't know all that much about what the surface of Venus, the rocky part of Venus, might be like. All we know is that it's really hot out in there. So if we think about the process of process of a collision and breaking a piece of, of planetary body, if you think about at an impactor coming in and colliding with the marshmallow-like surface of Venus, that becomes a bit of a challenge to be able to, to get some rocky material out.

Jim Green: Well, I also heard that you got involved in in analyzing some samples from one of the Japanese missions called Hayabusa2. Did you just get thesr samples and, and what do they like?

Neyda Abreu: Well, this is really quite an amazing opportunity. And I am so incredibly grateful to the Japanese team for letting us, being part of something that has taken so much time, so much effort, so much dedication, from JAXA and being able to share those samples internationally.

Neyda Abreu: But Hayabusa 1 and 2 went to asteroids. So these are the first time(s) that we get samples directly from asteroids. So these missions are the first opportunity that we've ever had to say, these samples come from this asteroid, and being able to create a bigger story around how they might have formed. So it's an incredible opportunity.

Jim Green: Well, they must also be related in a way to perhaps the development of life or providing an environment for which life could have started. What do we know about their relationship to life on Earth?

Neyda Abreu: So we are learning more and more as we go. Over the years that I have been involved in planetary sciences, we really have learned quite a bit about, first of all, the variety of the different organic compounds that that we can find in meteorites. We have also been able to ask questions about in what environments they could have formed. Some organics, some people theorize that they form in the interstellar medium, so interstellar space, some of them could have formed in the asteroids themselves. One line of thinking is that those asteroids would give us enough of a high temperature and enough water to be able to have those molecules interact with each other, become more complex. And they also give us surfaces in which those reactions can occur. Some of these minerals can act as catalysts for reactions that are happening, allowing for the more complex chemistry to occur. How that jump from having amino acids and sugars and hydrocarbons in carbonaceous chondrites goes into forming RNA or DNA, that's a big gap. And we are still trying to understand that. That is a very active area of research. But it really feels like the more meteorites we get, the more variety of different environments that we can trace those meteorites to. And now the Hayabusa2 samples, the Hayabusa samples as well, the more we can understand how this happened, because obviously, the organics came with the rocky stuff. So at some point, (laughs) they had to have been able to form these more complex organic chemistry.

Jim Green: Right. So before life can get started, you at least have to start out with all the right material.

Neyda Abreu: Yeah.

Jim Green: Well, you're currently working at NASA's Langley Research Center in Virginia as the senior advocate for science and research, what exactly is that position all about?

Neyda Abreu: Well, if you can find a dream job for me, that would be it. My job is to basically find the obstacles that keep scientists and researchers in engineering, from accomplishing their goals and try to find solutions for those, advocate for solutions for those. So when I was thinking about what my next step as a scientist was, I was a professor, and I was working on my research, it really felt that the most important thing that I could do was to help others. And this is an incredible opportunity to do that.

Jim Green: Well, Neyda, I always like to ask my guests to tell me what that person place or event was that got them so excited about being in the sciences they are today. And I call that event a gravity assist. So Neyda, what was your gravity assist?

Neyda Abreu: Well, I, I had an interesting set of events, actually. And obviously, I've had a lot of wonderful people who have really contributed to my position in the sciences, to my interest in the sciences, etc. But if I were to go back in time, and go back to that initial moment, there were three events that happened when I was a first grader. And that is, when I decided that I wanted to work for NASA. So, no pressure there.

Jim Green: (laughs)

Neyda Abreu: And this was 1986, which was a very interesting year from the standpoint of NASA, very difficult year, in many ways. So between January and February of 1986, there were three events, one very personal, my great grandmother, who was very old and had a wonderful life passed, unfortunately. And there was also the terrible tragedy of the Challenger in early 1986. In the midst of all of these, a comet called Halley was making perihelion. Now, Halley is a fascinating comet. And one of the things that makes it really fascinating is that it comes by every 76 years.

Neyda Abreu: So when I was thinking about these tragedies, and the loss of life, and the cycle of life, and it was the first time that I thought about the things as a little kid, the idea of having this little piece of the solar system come with that regularity, and within the cycle of human life, really made me think about these big questions and these big cycles. So, as humans, we have birth, you grow, you have these adult stages, and then you die. And in some ways, stars do the same. And that was a shock.

Neyda Abreu: So it was those cycles, it was the ability to connect with others that have lived maybe thousands of years before me and with people who will live a thousand years into the future. And the stories that we were able to tell. I wanted to learn more about solar systems, how they formed, how these little bits of ice and rock traveled around and witness all our happy times, sad times, stable times, unstable times, and continue to tell stories about our world. So that's how I got to be a scientist.

Jim Green: Oh, wow. From very early on. That's fantastic. Well, Neyda, thanks so much for joining me.

Neyda Abreu: Well, thank you so much for having me.

Jim Green: Well, join me next time as we continue our journey to look under the hood at NASA and see how we do what we do. I'm Jim Green, and this is your Gravity Assist.


Credits
Lead producer: Elizabeth Landau
Audio engineer: Manny Cooper
Last Updated: Mar 18, 2022
Editor: Gary Daines

Source: https://www.nasa.gov/mediacast/gravity-assist-these-space-rocks-have-seen-it-all-with-neyda-abreu
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Odp: [NASA Gravity Assist] : Season 5
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