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[AmericaSpace] On International Women's Day
« dnia: Marzec 09, 2019, 23:41 »
On International Women's Day, NASA Looks Forward to First All-Female EVA in Late March; Koch Tapped for Longer ISS Stay
By Ben Evans, on March 8th, 2019

Anne McClain and David Saint-Jacques at work with U.S. space suits in the Quest airlock aboard the International Space Station (ISS). Photo Credit: NASA

As the world observes International Women’s Day today (Friday, 8 March), we are reminded not only of the past accomplishments of female spacefarers—including Valentina Tereshkova, the first woman in space; Svetlana Savitskaya, the first woman to perform a spacewalk; Eileen Collins, the first woman to command a space mission; and Peggy Whitson, the first woman to lead a space station expedition—but of the promise of future achievements, as-yet unrealized.

In the coming weeks, NASA plans three periods of Extravehicular Activity (EVA) outside the International Space Station (ISS), involving four first-time spacewalkers from the United States and Canada. On the second of those three EVAs, on 29 March, U.S. astronauts Anne McClain and Christina Koch will make history by performing the first-ever all-female spacewalk. And according to NASA, Koch may remain aboard the station to achieve the second-longest single mission ever performed by a woman.

On Mission 41G, Kathy Sullivan became the first U.S. female spacewalker. Photo Credit: NASA

All told, just 62 women from the United States, Russia, Canada, Italy, France, Japan, the United Kingdom, South Korea and China have achieved Earth-orbital flight between Tereshkova’s pioneering mission on Vostok 6 in June 1963 and the launch of NASA’s Anne McClain aboard Soyuz MS-11 last December. Fewer still have performed spacewalks, with a mere 12 women to date—out of a total of more than 200 astronauts—having departed their orbital spacecraft, clad in pressurized suits, to work in near-total vacuum.

Yet the 37 EVAs conducted between July 1984 and, most recently, May 2017, which have included female spacewalkers, have been responsible for some of the most remarkable accomplishments in human exploration of the cosmos.

Spacewalker Kathy Thornton is dwarfed by Hubble’s solar array as she prepares to release it into space, during STS-61 in December 1993. Photo Credit: NASA

The Soviet Union’s Svetlana Savitskaya was the first woman spacewalker, spending 3.5 hours working outside the Salyut 7 space station in July 1984, after which NASA’s Kathy Sullivan did likewise outside shuttle Challenger the following October. Savitskaya evaluated a new space-welding tool, whilst Sullivan trialed an in-space refueling mechanism.

The first woman to make two EVAs was also the first woman to make three—Kathy Thornton, who supported Space Station Freedom construction tests on STS-49 in May 1992, then became the only female spacewalker to work on the Hubble Space Telescope (HST) during STS-61 in December 1993—and Linda Godwin stands alone as the only woman to spacewalk outside two discrete space stations, namely Mir and the ISS.

Linda Godwin (left), pictured during STS-108 training, became the first woman to spacewalk outside two discrete space stations. Photo Credit: NASA

Susan Helms was a participant on the longest EVA ever conducted—a marathon, eight-hour-and-56-minute excursion, back in March 2001—whilst the current incumbent record-holder is former NASA Chief Astronaut Peggy Whitson, who has totaled 60 hours and 21 minutes in vacuum, across ten EVAs between August 2002 and May 2017. This positions her fourth on the list of most experienced spacewalkers in the world, sitting just behind seasoned Russian heavyweight Anatoli Solovyov and NASA veterans Mike Lopez-Alegria and Drew Feustel.

For several years, an element of unspoken lighthearted competition existed between Whitson and fellow NASA astronaut Suni Williams, as the mantle of most experienced female spacewalker pingponged between them. Williams has presently logged over 50 hours across her seven EVAs, whilst five other women—Tammy Jernigan, Heidemarie Stefanyshyn-Piper, Nicole Stott, Tracy Caldwell-Dyson and Kate Rubins—have spacewalked outside the ISS. Of those, Jernigan was the first woman to spacewalk outside the ISS, way back in May 1999.

Susan Helms translates along the wall of the shuttle’s payload bay during her STS-102 EVA with Jim Voss. This spacewalk in March 2001 remains the longest EVA ever conducted, at eight hours and 56 minutes. Photo Credit: NASA

Several of those female spacewalkers have adopted the leadership mantle on their EVAs, serving as “EV1”, although at no point in history has an all-female spacewalk ever taken place. That will occur for the first time on 29 March, when incumbent Expedition 58 astronaut Anne McClain and her soon-to-be-launched crewmate Christina Koch step outside the ISS to continue work to replace a set of 12 aging nickel-hydrogen batteries in Power Channels 2A and 4A in the station’s P-4 truss with six smaller and more capable lithium-ion ones.

Current plans—outlined by NASA last month—call for McClain and Nick Hague to perform a spacewalk on 22 March to begin the work, after which McClain and Koch will make the second EVA a week later and Hague and Canadian astronaut David Saint-Jacques will venture outside on 8 April to install truss jumpers and additional ethernet cable connections. For both of her EVAs, McClain will serve as EV1.

Shane Kimbrough (left) and the world’s most experienced female spacewalker Peggy Whitson (right), at work during EVA-41. Photo Credit: NASA/Twitter/Thomas Pesquet

Much speculation has abounded in recent months about the return schedule for various U.S. and Russian crew members, later this year, particularly in light of the fact that the first United Arab Emirates (UAE) spacefarer is expected to fly a short-duration mission of around ten days aboard Soyuz MS-15 in September. To free up a seat aboard Soyuz MS-12 for his return to Earth, it has been suggested that a Soyuz MS-12 crew member may enjoy a longer than nominal stay aboard the ISS. In comments provided to AmericaSpace, NASA’s Rob Navias explained definitively that “Hague returns to Earth in October”.

Launching alongside the UAE spaceflight participant are expected to be Russian cosmonaut Oleg Skripochka—who will rejoin his one-time crewmate Christina Koch—and former NASA Chief Astronaut Chris Cassidy, who will remain aboard the space station until late spring 2020. According to Mr. Navias, “we expect Koch to remain on-board ISS” beyond October, with Ovchinin and Hague joining the UAE astronaut aboard Soyuz MS-12 for the return to Earth on 3 October. Asked if Koch would return on Soyuz MS-13 in December, or remain aboard even longer, returning on Soyuz MS-15 in April 2020, Mr. Navias advised that “the Flight Program is under review”. In either case, a landing in December 2019 or later will provide Koch with a minimum-duration mission of nine months aboard the ISS, the second-longest duration ever achieved by a female spacefarer on a single mission, after Peggy Whitson.


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Odp: [AmericaSpace] On International Women's Day
« Odpowiedź #1 dnia: Marzec 26, 2019, 19:12 »
Spacesuit issue cancels first all-female spacewalk
by Jeff Foust — March 26, 2019

NASA astronaut Anne McClain during a March 22 spacewalk. A decision by McClain to use a smaller spacesuit led NASA to reshuffle assignments for upcoming spacewalks, in the process cancelling what would have been the first all-female EVA. Credit: NASA

WASHINGTON — A spacesuit sizing issue has prompted NASA to reshuffle assignments for a pair of upcoming spacewalks at the International Space Station, cancelling a first-ever all-woman spacewalk and in the process turning what had been an accidental public relations coup for the agency into a headache.

NASA announced March 25 that Anne McClain, who performed a spacewalk with fellow NASA astronaut Nick Hague March 22, won’t participate in another spacewalk scheduled for March 29 with Christina Koch. Hague will instead perform the spacewalk with Koch to replace batteries that are part of the station’s power system.

The agency said it made the change after McClain found that she would be more comfortable wearing a suit with a medium-sized hard upper torso segment, rather than the large size she wore on the earlier spacewalk. Only one suit with a medium-sized torso is ready for use on the station, and station managers decided to have Koch use that suit.

There were no signs in the earlier spacewalk by McClain that the larger suit was a problem. An agency spokesperson said March 25 that McClain trained for the spacewalks on the ground in using medium and large torso segments, and initially thought that the larger suit would work, but concluded after the March 22 spacewalk that the smaller suit would be more comfortable.

Even with extensive training on the ground, getting the right fit for a spacesuit in microgravity can be a challenge. “When they launch on board, we know pretty well what suit size they are but, of course, your body changes slightly in space due to fluid shifts or spine elongation,” said Mary Lawrence, a NASA spacewalk flight director, during a March 19 press conference about the spacewalks.

A relatively routine reshuffling of crew assignments generated extra attention, and scrutiny, because of the historical significance of the planned spacewalk. Had the previous schedule held, a Koch-McClain spacewalk would have been the first in the history of spaceflight featuring only women.

“Anne and Christina will have the opportunity to be the first all-female EVA, which I think will be a proud moment for NASA, if the assignments stay as they planned,” Lawrence said at that briefing. “If they inspire that next generation of space explorers, they’re certainly worthy of that inspiration, and I’m just really proud to be a part of it.”

Agency officials, though, emphasized they did not deliberately team up Koch and McClain for that milestone. “There were a lot of circumstances that got us here,” said Kenny Todd, manager for ISS operations and integration at NASA, during the same briefing. Among those factors were delays in the spacewalk caused by changes in crew assignments and schedules after the aborted Soyuz MS-10 launch last October.

Another factor, he said, was giving spacewalk experience to as many astronauts as possible. “We’ve got a lot of young crew members here. Chances are they’re going to see space again at some point and, as much as we can, we’d like to make them veteran spacewalkers.”

Todd said that the historical significance didn’t immediately dawn on him or others planning the spacewalk. “It just wasn’t something that jumped out at us,” he said.

While NASA didn’t deliberately plan an all-woman spacewalk, it enjoyed the extra attention paid to it. That attention, though, created a backlash in social media when NASA announced the reassignment, with some people accusing the agency of sexism for not having enough medium-sized suits on the station or not being willing to delay the spacewalk until a solution could be found to allow Koch and McClain to perform an EVA together.

NASA later noted that there is a second medium-sized spacesuit torso on the station, but it is not currently configured for a spacewalk. An agency spokesperson said it’s easier to change the spacewalk crew assignments and keep to the current schedule than to reconfigure the spacesuits and delay the EVAs.

Delaying the spacewalk would pose other schedule challenges as well. Todd noted at the earlier briefing that April will be a busy month at the station with three cargo vehicles slated to arrive there. A Russian Progress cargo spacecraft is scheduled to launch to the station April 4, followed by a Northrop Grumman Cygnus spacecraft April 17. A SpaceX Dragon cargo spacecraft will follow in late April.

McClain, while not participating in this EVA, will take part in another spacewalk. NASA announced March 25 that she and Canadian astronaut David Saint-Jacques will perform the third and last in the current series of spacewalks on April 8.


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Odp: [AmericaSpace] On International Women's Day
« Odpowiedź #2 dnia: Październik 19, 2019, 08:02 »
For All Womankind: Koch and Meir Complete Historic All-Female Spacewalk
By Ben Evans, on October 18th, 2019 [AS]

Christina Koch (with red stripes) was making her fourth career Extravehicular Activity (EVA), whilst Jessica Meir became the 14th U.S. woman and the 15th woman in history—when one also counts Russia’s Svetlana Savitskaya—to perform a spacewalk. Photo Credit: NASA

Thirty-five years to the month since Kathy Sullivan carved her name in the annals of history by becoming America’s first female spacewalker, another record was set for the United States and the world earlier today (Friday, 18 October) when Expedition 61 astronauts Christina Koch and Jessica Meir embarked on the world’s first all-woman Extravehicular Activity (EVA). The duo—with Koch making her fourth career EVA, serving as “EV1”, with red stripes on her space suit for identification, and first-timer spacewalker Meir as “EV2”, in a pure white suit—spent seven hours and 17 minutes outside the International Space Station (ISS) replacing a failed Battery Charge/Discharge Unit (BCDU) and tending to a number of get-ahead tasks. In addition to its obvious significance as the first-ever all-female EVA, today’s U.S. EVA-58 saw Koch jump in the rankings to become the world’s fourth most experienced woman spacewalker.

Jessica Meir (left) with Christina Koch during an Extravehicular Mobility Unit (EMU) fit-check earlier this week. Photo Credit: NASA

Although never intended as a gender-focused political stunt, an all-female spacewalk first entered the realms of possibility in March 2019, when NASA revealed its intent to send Expedition 59 astronauts Anne McClain and Christina Koch outside the ISS to help install new batteries onto the station’s P-4 truss. As circumstances transpired, the lack of availability of suitably-sized Extravehicular Mobility Units (EMUs) precluded an all-female EVA at that point in time and the spacewalk was instead done by McClain and her Expedition 59 crewmate Nick Hague. Hopes of sending two women outside at the same time were rekindled a second time on 4 October, when NASA announced that Koch and her newly-arrived Expedition 61 crewmate Jessica Meir would pair up for the fourth of five planned EVAs to remove 12 aging nickel-hydrogen batteries from the P-6 truss and replace them with six upgraded lithium-ion units.

That spacewalk, originally scheduled for 21 October, was postponed earlier this week when the need arose to remove and replace a failed Battery Charge/Discharge Unit (BCDU). Part of the station’s electrical power system, the BCDUs are responsible for regulating the amount of charge to the batteries from the eight Solar Array Wings (SAWs). Two spacewalks, conducted by Expedition 61 astronauts Koch and Drew Morgan, took place on 6 October and 11 October and successfully began the process of removing and replacing the old nickel-hydrogen batteries in the P-6 truss with new lithium-ion units. However, shortly after the completion of the second EVA, the BCDU failed to activate and the remaining three spacewalks were put on hold until it could be replaced. “The station’s overall power supply…remains sufficient for all operations and the failed unit has no impact on the crew’s safety of ongoing laboratory experiments,” NASA explained. “However, the failed power unit does prevent a new lithium-ion battery installed earlier this month from providing additional station power.”

Christina Koch is now the fourth most EVA-experienced woman in the world. Photo Credit: NASA

The failed BCDU has been operational since the P-6 truss was installed onto the station by the STS-97 shuttle crew, way back in December 2000. There are currently several replacement units stored on the exterior of the ISS and the one used for today’s changeout has itself been in space for over 12 years, having been delivered by the STS-118 shuttle crew in August 2007. And by happenstance, one of the STS-118 crew—veteran spacewalker Tracy Caldwell Dyson—was on hand for NASA TV’s coverage of U.S. EVA-58. In her commentary, she played down the significance of the first all-female EVA. “I think the milestone is hopefully this will now be considered normal,” she said, pointing out that women have performed numerous EVAs since 1984. “I think many of us are looking forward to this just being normal.”

Assisted into their suits this morning by Drew Morgan, and with Expedition 61 Commander Luca Parmitano at the controls of the 57.7-foot-long (17.6-meter) Canadarm2 robotic arm, Koch and Meir moved swiftly through their pre-EVA protocols and switched their suits onto battery power at 7:38 a.m. EDT. This officially began U.S. EVA-58. In addition to the BCDU replacement task, Koch and Meir also installed a stanchion onto Europe’s Columbus lab, in readiness for the arrival of the Bartolomeo external payload anchoring platform next spring. Returning to the Quest airlock after seven hours and 17 minutes, theirs was the longest of the eight EVAs—seven in U.S. suits, one in Russian-made suits—performed so far in 2019.

With ten EVAs and over 60 hours spent outside the International Space Station (ISS), Peggy Whitson is the world’s most experienced female spacewalker. Photo Credit: NASA

It also left Koch in fourth place on the world list of most experienced female spacewalkers. She sits behind EVA heavyweights Peggy Whitson, Sunita Williams and Heidemarie Stefanyshyn-Piper with a total of 27 hours and 48 minutes across her four career EVAs to date. Yet even this cadre of EVA veterans stand on the shoulders of other women astronauts—and a cosmonaut—who went before them. The first female spacewalker was the Soviet Union’s Svetlana Savitskaya, who spent three hours and 33 minutes outside the Salyut 7 space station in July 1984, testing a space welding tool. Three months later, in October 1984, shuttle astronaut Kathy Sullivan logged three hours and 29 minutes as America’s first woman spacewalker.

Sadly, although Sullivan came close to making another spacewalk on the Hubble Space Telescope (HST) in April 1990, it was almost a decade before the next woman pushed herself out of the shuttle’s airlock hatch and into space. In May 1992, on the maiden voyage of shuttle Endeavour, Kathy Thornton chalked up an EVA of seven hours and 45 minutes—longer than the spacewalks of Savitskaya and Sullivan, put together—to practice Space Station construction methods. And Thornton went on to log two more EVAs in December 1993 to repair Hubble itself, establishing herself as the most experienced female spacewalker with a cumulative 21 hours and 11 minutes spent outside a spacecraft. It was a record she held unchallenged for more than a decade.

Thirty-five years ago this month, Kathy Sullivan became America’s first woman spacewalker. Today, two of her successors performed the first all-female EVA. Photo Credit: NASA

In March 1996, Linda Godwin became the first U.S. female to clamber outside a space station, whilst shuttle Atlantis was docked to Russia’s Mir orbital outpost. Later in her career, Godwin also spacewalked outside the ISS, becoming the first woman to perform EVAs in support of two discrete space stations.

There have been disappointments in the annals of female EVAs, too, and not just after the lost McClain-Koch spacewalk earlier this year. Way back in November 1996, astronaut Tammy Jernigan was slated to perform two excursions on STS-80—in what would have been the first EVAs ever successfully performed from shuttle Columbia—but a jammed airlock hatch handle prematurely scuppered those plans. Jernigan eventually got her chance in May 1999, when she became the first woman to spacewalk outside the ISS. Others were less lucky. Wendy Lawrence was prevented from flying a long-duration mission to Mir, in part because of difficulties sizing the Russian space suit for her small frame.

Spacewalking by women reached its high-watermark in March 2001, when Susan Helms and crewmate Jim Voss spent a combined eight hours and 55 minutes outside the ISS in what remains the longest single EVA in human history. And as ISS construction and maintenance entered high gear, female shuttle astronauts and female ISS expedition residents participated in assembling the giant orbital laboratory.

Susan Helms’ EVA in March 2001 remains the longest in space history, having lasted eight hours and 55 minutes. Photo Credit: NASA

U.S. astronauts Peggy Whitson and Sunita Williams, across five ISS increments between 2002 and 2017, passed the torch repeatedly between one another to become the most experienced female spacewalker; as of today, Whitson stands as the record-holder, with a combined 60 hours and 21 minutes across ten career EVAs. Williams currently sits in second place, her seven EVAs totaling 50 hours and 40 minutes. In third place is Heidemarie Stefanyshyn-Piper on 33.5 hours across five EVAs, with Christina Koch in fourth place.

But as Tracy Caldwell Dyson—whose three contingency spacewalks in August 2010 logged her nearly 23 hours outside the space station—remarked earlier this week, the milestone of the first all-female EVA will hopefully give way to a growing realization that of the normality of having women performing intricate tasks in the vacuum of space and, someday, on the surface of the Moon or Mars.


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« Odpowiedź #3 dnia: Październik 19, 2019, 21:50 »
NASA astronauts complete repairs on historic spacewalk
by Jeff Foust — October 18, 2019 [SN]

NASA astronauts Christina Koch and Jessica Meir work outside the ISS Oct. 18 on the agency's first all-female spacewalk. Credit: NASA

WASHINGTON — Two NASA astronauts successfully replaced a faulty battery charger during the agency’s first all-female spacewalk Oct. 18, an event that at times appeared to go better in orbit than on the ground.

NASA astronauts Christina Koch and Jessica Meir spent seven hours and 17 minutes outside the International Space Station during a spacewalk, carrying out their primary task of replacing a battery charge/discharge unit (BCDU) on one end of the station’s truss. Controllers confirmed during the spacewalk that a spare BCDU installed in place of the faulty unit was working properly.

NASA announced Oct. 15 that it was rescheduling a series of spacewalks that started Oct. 6 to replace batteries that are part of the station’s power supply after the BCDU unit failed to turn back on after the second in that series of five spacewalks Oct. 11. Koch and Meir, who had been scheduled to perform a spacewalk together Oct. 21 as part of the battery swap process, were instead assigned to this new spacewalk to replace the BCDU.

The remaining battery swap spacewalks have been postponed for up to a few weeks to allow engineers to study why this unit failed, and if it’s related to the failure of another BCDU elsewhere on the station earlier this year.

After replacing the faulty unit, the astronauts performed several other unrelated “get-ahead” tasks. That included installing hardware on the exterior of the station’s European Columbus module that will support an external experiment rank called Bartolomeo that be installed there next year.

The spacewalk was the first for Meir, who is the 15th woman — all but one American — to walk in space. The spacewalk was Koch’s fourth, who now has nearly 28 hours of EVA time.

The spacewalk gained extra attention because it was the first time two women walked in space together. Many hailed that historic milestone while also regretting that it took so long into the Space Age for it to take place.

Koch and Anne McClain had been set to make history with an all-woman spacewalk earlier this year, but NASA was forced to change spacewalk assignments when McClain found she needed a different sized suit than originally planned. That led to public criticism of NASA for not having the right sized suits.

“People are going to respond the way they respond,” NASA Administrator Jim Bridenstine said in a media briefing shortly before the start of the spacewalk when asked about the public reaction to both this spacewalk and the cancelled one from earlier this year. “We are focused on mission success. We want to make sure that, every time we do a spacewalk, we’re doing it with purpose, to accomplish objectives that are in the best interest of the United States of America.”

Prior to the spacewalk, agency officials said they selected Koch and Meir for the spacewalk because they were the best available based on their training and the need to balance workloads for them and the other astronauts on the station. “We have the right people doing the right job at the right time,” Bridenstine said. “We are confident that Christina Koch and Jessica Meir will be able to accomplish this mission.”

NASA, though, also played up the historic aspect of this spacewalk, with Bridenstine calling the two “an inspiration to the world.” At NASA Headquarters, the agency invited several members of Congress, including members of the House Science Committee and the House appropriations subcommittee that funds NASA, to sit in an operations room to watch the opening phases of the spacewalk.

In the middle of the spacewalk, Koch and Meir took a phone call from President Donald Trump at the White House, who congratulated them on the milestone. “What you do is incredible,” he said in comments that also played up NASA plans to return to the moon and, from there, go to Mars.

Trump, though, misstated the achievement, calling it “the first-ever female spacewalk.” Meir corrected him. “We don’t want to take too much credit, because there have been many other female spacewalkers before us,” she said. “This is just the first time that there have been two women outside at the same time.”

Earlier in the day, Ken Bowersox, a former astronaut who is the acting associate administrator for human exploration and operations, raised eyebrows when he suggested women weren’t as suited as men to perform spacewalks. “There are some physical reasons that make it harder, sometimes, for women to do spacewalks,” he said at the media briefing. He argued that, like professional basketball, taller people were better, which tended to favor men.

“Spacewalks are one of those areas where just how your body is built and shaped, it makes a difference in how well you can work the suit,” he said. He added later that a “certain amount of strength” was needed that tended to favor men.

“We also brought women into the crews because of their brains,” he added. “By using their brains, they can overcome a lot of those physical challenges.”

Bridenstine, who earlier emphasized that NASA’s next-generation suits would be designed to fit a much broader range of both women and men to overcome of the male-centric design biases of older suits, stepped in. “I think it’s also important to note that there are physical attributes of women that make them better at spaceflight than men,” he said, such as lower intracranial pressure that has been linked to eyesight problems during long-duration spaceflight.

“There are biological benefits that women have that men do not have to microgravity spaceflight,” he continued. “When we do different missions, it’s going to take all of America to do it.”


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« Odpowiedź #4 dnia: Październik 19, 2019, 22:06 »
Koch, Meir conclude first all-female spacewalk
October 18, 2019 William Harwood [SFN]

Astronaut Jessica Meir during Friday’s spacewalk. Credit: NASA TV/Spaceflight Now

Astronauts Christina Koch and Jessica Meir carried out history’s first all-female spacewalk Friday, floating outside the International Space Station and successfully installing a 230-pound replacement battery charger in the lab’s solar power system. The historic excursion was carried out in a blaze of public interest that rose all the way to the White House.

“I just want to congratulate you, what you do is incredible,” President Trump told the spacewalkers in a surprise call from the White House. He was joined by Vice President Mike Pence, daughter Ivanka and NASA Administrator Jim Bridenstine.

“You’re very brave people, I don’t think I want to do it, I must tell you that,” the president said. “But you are amazing people. … Congratulations, Christina and Jessica, on this historic event.”

“Thank you,” Meir replied from orbit. “We don’t want to take too much credit because there have been many other female spacewalkers before us. This is just the first time there have been two women outside at the same time. … For us, this is really just us doing our job.

“At the same time, we recognize that it is an historic achievement and we do, of course, want to give credit to all those who came before us. There has been a long line of female scientists, explorers, engineers and astronauts, we are following in their footsteps to get us where we are today.”

The spacewalk began at 7:38 a.m. EDT when Koch, making her fourth excursion, and Meir, making her first, switched their spacesuits to battery power inside the Quest airlock, kicking off 221st station spacewalk since assembly began in 1998. It was the first by two women in the 54 years since the first “extra-vehicular activity,” or EVA, by a Russian cosmonaut in 1965, sparking widespread public interest.

Despite the unusual level of scrutiny, Friday’s spacewalk was a strictly-business affair to replace a faulty 232-pound battery charger in the lab’s solar power system. Any two of the space station’s four NASA sponsored astronauts could have done the work — they all received similar training — but Koch and Meir got the nod.

After floating out of the airlock, Koch promptly made her way to the left side of the station’s power truss, anchored her feet on the end of the lab’s robot arm and unbolted a spare battery controller. Meir, meanwhile, made her way outboard to the left-most solar array and prepared the faulty unit for removal from an equipment bay.

The two then teamed back up. Koch handed the controller off to Meir and got off the arm. The astronauts then carefully carried the spare out to the port 6, or P6, solar array segment work site more than 50 yards from the airlock. While such components do not weigh anything in the microgravity environment of low-Earth orbit, they still have the same mass, requiring care when starting and stopping motion.

But the spacewalkers had no problems, easily moving the bulky controller to the work site and installing it in place of the faulty unit. After an initial health check, flight controllers stood by while the system came back on line.

“Christina, Jessica, to give you a report on your work today, we show the battery charge-discharge unit is fully powered up and working,” astronaut Stephanie Wilson radioed from mission control toward the end of the seven-hour 17-minute spacewalk. ”

“That is awesome news, thank you,” Koch replied. Added Meir: “Amazing news, Stephanie. That makes us very happy.”

NASA astronauts Jessica Meir and Christina Koch. Credit: NASA

Soviet cosmonaut Alexey Leonov carried out history’s first spacewalk in 1965. Cosmonaut Svetlana Savitskaya became the first woman to walk in space during an outing with a male cosmonaut in 1984, followed later that year by NASA astronaut Kathy Sullivan, who joined astronaut David Leestma for a shuttle spacewalk.

While NASA managers and even the astronauts tend to view the all-female spacewalk as “just another milestone,” it took on heightened significance in the wake of a spacesuit sizing problem earlier this year that forced the station crew to call off plans for Koch and astronaut Anne McClain to make the first all-female EVA.

The station now is equipped with components for four suits, accommodating all three of NASA’s crew members as well as European Space Agency astronaut Luca Parmitano.

Koch and Meir already were paired up for one of five spacewalks to replace aging solar array batteries. But after two of those excursions, a battery charge-discharge unit, or BCDU, failed knocking a newly-installed battery off line.

While the remaining battery installation spacewalks were put on hold, NASA managers opted to keep the Koch-Meir pairing intact, assigning them instead to the BCDU change out.

“One of these days, working in space like that is going to be routine,” said former astronaut Ken Bowersox, now deputy chief of NASA’s human space program. “We won’t get together to celebrate an occasion when two women, or two men, or a man and a woman, or three or four go outside, it’ll just be routine.

“That’s what we’re doing on ISS, we’re gathering that experience that we need to make spaceflight routine so we can move farther out into our solar system, to go to the moon and on to Mars someday. That’s what excites me the most, to see that progress happening.”

The station’s electricity is provided by four huge solar wings, two on each end of a truss that stretches the length of a football field. Two dozen battery charge controllers, six per solar wing, divert electricity to powerful batteries for recharging when the lab is in sunlight and then deliver that stored power when the station moves through Earth’s shadow.

Replacing the faulty BCDU effectively restored 4 to 5 kilowatts of power to the lab’s electrical system that was lost when the original charger failed after 19 years of normal operation, knocking a newly-installed lithium-ion battery off line.

With the BCDU swap-out complete, Koch and Meir carried the faulty unit back to the airlock for eventual return to Earth aboard a future SpaceX Dragon cargo ship for troubleshooting and, if possible, repair.

They then carried out a few other, more routine tasks, adjusting multi-layer insulation around spare components to make access easier, securing an ethernet cable and installing a fitting on the European Space Agency’s Columbus laboratory module that will be needed when an experiment platform is attached later.

Because batteries lose their ability to recharge over time, NASA is in the process of replacing all 48 of the space station’s older-generation nickel-hydrogen batteries with 24 more powerful lithium-ion power packs, along with circuit-completing “adapter plates” to fill in for batteries that were removed but not replaced. In the upgraded system, each lithium-ion battery is charged and discharged by a single BCDU.

In 2017, spacewalkers replaced the 12 right-side inboard solar array batteries with six lithium-ion units. Last March, the 12 left-side inboard batteries were replaced. NASA currently is working to replace the left-side outboard batteries. The final set of lithium-ion batteries will be installed in the right-side outboard arrays next year

Three of six lithium-ion batteries were installed on the left outboard array during spacewalks Oct. 6 and 11 by Koch and Morgan. Shortly thereafter, engineers discovered one of the three BCDUs in that circuit had failed, sidelining one of the new batteries.

The failure is troubling because an identical charger failed last March after a new battery was installed for the left inboard array. NASA engineers want to make sure a generic problem of some sort is not present before proceeding with additional battery installations.