Autor Wątek: Artykuły o DART (Double Asteroid Redirection Test)  (Przeczytany 616 razy)

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Artykuły o DART (Double Asteroid Redirection Test)
« dnia: Czerwiec 11, 2020, 19:36 »
NASA awards DART launch contract to SpaceX
by Jeff Foust — April 11, 2019


SpaceX will launch NASA's DART mission, which will fly to the near Earth asteroid Didymos and collide with its small moon as a planetary defense demonstration. Credit: JHUAPL

DENVER — SpaceX will launch a NASA mission to test an asteroid deflection technique at a significantly lower price than past agency contracts won by the company.

NASA said April 11 it awarded SpaceX a contract to launch the Double Asteroid Redirection Test (DART) on a Falcon 9 in June 2021 from Vandenberg Air Force Base in California. The total cost to NASA for the mission, including the launch and related services, is $69 million.

DART is a mission under development at the Johns Hopkins University Applied Physics Laboratory as part of NASA’s planetary defense program. The spacecraft will use an electric propulsion system to travel to the asteroid Didymos. DART will collide with a small moon orbiting Didymos, sometimes nicknamed Didymoon, at a speed of six kilometers per second.

Astronomers will measure the change in the moon’s orbit around Didymos as a result of the impact to measure how well the energy of the impact was transferred to the moon. That will help scientists gauge the effectiveness of the “kinetic impactor” approach proposed as one means of deflecting an asteroid on a collision course with the Earth.

DART originally planned to launch as a rideshare on the commercial launch of a geostationary orbit satellite. The mission switched several months ago to a dedicated launch. NASA did not disclose if DART, which weighs about 500 kilograms, will share the launch vehicle with another spacecraft.

The $69 million launch price is significantly lower than past NASA contracts for Falcon 9 launches. NASA awarded SpaceX a contract for the Sentinel-6A satellite in October 2017 for a November 2020 launch on a Falcon 9 from Vandenberg at a total cost of $97 million. The Surface Water and Ocean Topography (SWOT) satellite will launch on a Falcon 9 in April 2021 under a contract awarded in November 2016 at a value of $112 million.

“SpaceX is proud to continue our successful partnership with NASA in support of this important interplanetary mission,” SpaceX President Gwynne Shotwell said in a company statement. “This award underscores NASA’s confidence in Falcon 9’s capability to perform critical science missions while providing the best launch value in the industry.”

The award of the DART contract to SpaceX comes a week after the company dropped its protest of another NASA launch contract awarded earlier this year to United Launch Alliance for the Lucy mission. SpaceX had claimed, when it filed the protest in February, that it could launch the mission at a significantly lower cost than ULA’s Atlas 5.


Source: https://spacenews.com/nasa-awards-dart-launch-contract-to-spacex/
« Ostatnia zmiana: Listopad 23, 2021, 16:44 wysłana przez Orionid »

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Odp: [SN] NASA awards DART launch contract to SpaceX
« Odpowiedź #1 dnia: Czerwiec 11, 2020, 19:38 »
Future of asteroid deflection mission to be decided soon
January 19, 2017 Stephen Clark [SFN]


Artist’s concept of the European-built AIM spacecraft, along with two proposed deployable CubeSats, observing the collision of NASA’s DART impactor with the moon of asteroid Didymos. Credit: ESA – ScienceOffice.org

Decisions on the future of a joint robotic mission between NASA and the European Space Agency to demonstrate the ability to deflect an asteroid on a collision course with Earth have been put off until later this year after European governments declined to fully fund their part of the project in December.

(...)
Source: https://spaceflightnow.com/2017/01/19/future-of-asteroid-deflection-mission-to-be-decided-soon/

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Odp: [SN] NASA awards DART launch contract to SpaceX
« Odpowiedź #2 dnia: Czerwiec 11, 2020, 19:39 »
Planetary Defense Researchers Simulate Earth-Bound Asteroid Deflection
By LAWRENCE LIVERMORE NATIONAL LABORATORY APRIL 4, 2020


Lawrence Livermore researchers compared results of asteroid deflection simulations to experimental data and found that the strength model has a substantial effect on momentum transferred. Credit: Lawrence Livermore National Laboratory

Planetary defense researchers at Lawrence Livermore National Laboratory (LLNL) continue to validate their ability to accurately simulate how they might deflect an Earth-bound asteroid in a study that was published in the April issue of the American Geophysical Union journal Earth and Space Science.

The study, led by LLNL physicist Tané Remington, also identified sensitivities in the code parameters that can help researchers working to design a modeling plan for the Double Asteroid Redirection Test (DART) mission in 2021, which will be the first-ever kinetic impact deflection demonstration on a near-Earth asteroid.   

Asteroids have the potential to impact Earth and cause damage at the local to global scale. Humankind is capable of deflecting or disrupting a potentially hazardous object. However, due to the limited ability to perform experiments directly on asteroids, understanding how multiple variables might affect a kinetic deflection attempt relies upon large-scale hydrodynamic simulations thoroughly vetted against relevant laboratory‐scale experiments.

“We’re preparing for something that has a very low probability of happening in our lifetimes, but a very high consequence if it were to occur,” Remington said. “Time will be the enemy if we see something headed our way one day. We may have a limited window to deflect it, and we will want to be certain that we know how to avert disaster. That’s what this work is all about.”

This study investigated the accuracy of the codes by comparing simulation results to the data from a 1991 laboratory experiment conducted at Kyoto University, where a hyper-velocity projectile impacted a basalt sphere target.

Remington used an adaptive smoothed-particle hydrodynamics code named Spheral to produce simulation results that closely resemble the experimental findings. The simulations also helped the researchers identify which models and material parameters are most important to accurately simulate impact scenarios with a brittle, rocky asteroid.

They found that selection of the strength model and its parameters had a substantial effect on the predicted crater size and the amount of momentum transferred into the target asteroid. In addition to the strength model, the team found that simulation results also are sensitive to strain models and material parameters. 

These findings highlight the link between having properly validated codes and having the confidence needed to effectively plan a deflection mission. While no asteroids pose an immediate threat to Earth, LLNL researchers are collaborating with the National Nuclear Security Administration and NASA in the development of a modeling plan for the DART mission. These findings will help the team hone its modeling plan for DART.

The DART spacecraft will launch in late July 2021. The target is a binary (two asteroids orbiting each other) near-Earth asteroid named Didymos that is being intensely observed using telescopes on Earth to precisely measure its properties before impact. The DART spacecraft will deliberately crash into the smaller moonlet in the binary asteroid — dubbed Didymoon — in September 2022 at a speed of approximately 6.6 kilometers/second. The collision will change the speed of the moonlet in its orbit around the main body by a fraction of 1 percent, but this will change the orbital period of the moonlet by several minutes — enough to be observed and measured using telescopes on Earth.

“This study suggests that the DART mission will impart a smaller momentum transfer than previously calculated,” said Mike Owen, LLNL physicist, coauthor on the paper and developer of the Spheral code. “If there were an Earth-bound asteroid, underestimating momentum transfer could mean the difference between a successful deflection mission and an impact. It’s critical we get the right answer. Having real world data to compare to is like having the answer in the back of the book.”


Reference: “Numerical Simulations of Laboratory‐Scale, Hypervelocity‐Impact Experiments for Asteroid‐Deflection Code Validation” by T. P. Remington, J. M. Owen, A. M. Nakamura, P. L. Miller and M. Bruck Syal, 20 February 2020, Earth and Space Science.
DOI: 10.1029/2018EA000474

Source: https://scitechdaily.com/planetary-defense-researchers-simulate-earth-bound-asteroid-deflection/

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Odp: Artykuły o DART (Double Asteroid Redirection Test)
« Odpowiedź #3 dnia: Listopad 23, 2021, 16:45 »
NASA ready to launch DART planetary defense demonstration mission
by Jeff Foust — November 23, 2021 [SN]


SpaceX will launch NASA's DART mission, which will fly to the near Earth asteroid Didymos and collide with its small moon as a planetary defense demonstration. Credit: JHUAPL

WASHINGTON — NASA is ready to launch its first mission devoted to planetary defense, a spacecraft that will collide with the moon of a small asteroid to test the ability to deflect it.

Source: https://spacenews.com/nasa-ready-to-launch-dart-planetary-defense-demonstration-mission/

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Odp: Artykuły o DART (Double Asteroid Redirection Test)
« Odpowiedź #3 dnia: Listopad 23, 2021, 16:45 »

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Odp: Artykuły o DART (Double Asteroid Redirection Test)
« Odpowiedź #4 dnia: Listopad 24, 2021, 10:02 »
Falcon 9 launches DART
by Jeff Foust — November 24, 2021 [SN]


A SpaceX Falcon 9 lifts off Nov. 24 from Vandenberg Space Force Base in California carrying NASA's DART planetary defense mission. Credit: NASA/Bill Ingalls

WASHINGTON — A SpaceX Falcon 9 successfully launched a NASA mission that will deliberately collide with a near Earth asteroid to test a technique that could be used to deflect the trajectory of any future asteroid on a collision course with the Earth.

The Falcon 9 lifted off on schedule at 1:21 a.m. Eastern Nov. 24 from Space Launch Complex 4E at Vandenberg Space Force Base in California. The rocket’s upper stage deployed NASA’s Double Asteroid Redirection Test (DART) spacecraft about 55 minutes later, after two burns of that stage.

Source: https://spacenews.com/falcon-9-launches-dart/

Polskie Forum Astronautyczne

Odp: Artykuły o DART (Double Asteroid Redirection Test)
« Odpowiedź #4 dnia: Listopad 24, 2021, 10:02 »