Astronomy:Double Asteroid Redirection Test
DART mission in space
|Mission type||Planetary defense mission|
|Operator||NASA / APL|
|Manufacturer||Applied Physics Laboratory|
|Launch mass||500 kg (1,100 lb)|
|Dimensions||12.5 m × 2.4 m (41.0 ft × 7.9 ft)|
|Power||3.5 kW |
|Start of mission|
|Launch date||24 November 2021 |
|Rocket||Falcon 9 |
|Launch site||Vandenberg Air Force Base , SLC-4E|
|(65803) Didymos  impactor|
|Impact date||October 2022|
|Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO)|
Double Asteroid Redirection Test (DART) is a planned space probe that will visit the double asteroid Didymos and demonstrate the kinetic effects of crashing an impactor spacecraft into an asteroid moon for planetary defense purposes. The mission is intended to test whether a spacecraft impact could successfully deflect an asteroid on a collision course with Earth.
A demonstration of an asteroid deflection is a key test that NASA and other agencies wish to perform before the actual need of planetary defense is present. DART is a joint project between NASA and the Johns Hopkins Applied Physics Laboratory (APL), and it is being developed under the auspices of NASA's Planetary Defense Coordination Office.
In August 2018, NASA approved the project to start the final design and assembly phase.
Originally, the European Space Agency (ESA) and NASA had independent plans for missions to test asteroid deflection strategies, and by 2015 they struck a collaboration called AIDA involving two separate spacecraft launches that work in synergy. Under the proposal, the European spacecraft, AIM, would have launched in December 2020, and DART in July 2021. AIM would have orbited the larger asteroid to study its composition and that of its moon. DART would then impact the asteroid's moon in October 2022, during a close approach to Earth. AIM would have studied the asteroid's strength, surface physical properties, and its internal structure, as well as measure the effect on the asteroid moon's orbit around the larger asteroid.
On 11 April 2019, NASA announced that a SpaceX Falcon 9 would be used to launch DART. It was originally planned for DART to be a secondary payload on a commercial launch to keep costs low, however a mission update presentation in November 2018 noted that the mission has a dedicated launch vehicle.
Scientists estimate 25,000 large asteroids are in the Solar System, though to date, surveys have detected about 8000, therefore NASA officials think it is imperative to develop an effective plan should a near-Earth object threaten Earth.
DART is an impactor that hosts no scientific payload other than a Sun sensor, a star tracker, and a 20 cm aperture camera (Didymos Reconnaissance and Asteroid Camera for Optical navigation - DRACO) to support autonomous navigation to impact the small asteroid's moon at its center. It is estimated that the impact of the 500 kg (1,100 lb) DART at 6.6 km/s (4.1 mi/s)  will produce a velocity change on the order of 0.4 mm/s, which leads to a small change in trajectory of the asteroid system, but over time, it leads to a large shift of path. Overall, DART is expected to alter the speed of Dimorphos (Didymos B) orbit by about half a millimeter per second, resulting in an orbital period change of perhaps 10 minutes. Over a span of millions of kilometers, the cumulative trajectory change would turn a collision with a genuinely Earth-bound asteroid or comet into a safe outcome. The actual velocity change and orbital shift will be measured a few years later by a small spacecraft called Hera that would do a detailed reconnaissance and assessment. Hera was approved in November 2019.
DART spacecraft will use the NEXT ion thruster, a type of solar electric propulsion. It will be powered by 22 m2 solar arrays to generate the ~3.5 kW needed to power the NASA Evolutionary Xenon Thruster–Commercial (NEXT-C) engine. The spacecraft's solar arrays use a Roll Out Solar Array (ROSA) design, and this was tested on the International Space Station in June 2017 as part of Expedition 52, delivered to the station by the CRS-11 commercial cargo mission.
The DART impactor is proposed to make flyby observations of other near-Earth asteroids such as 2001 CB21 and 3361 Orpheus during its trajectory to 65803 Didymos. It will obtain some images in the visible spectrum.
The Italian Space Agency (ASI) will contribute a secondary spacecraft called LICIACube (Light Italian CubeSat for Imaging of Asteroids), a small 6-unit CubeSat that will piggyback with DART and will separate shortly before impact to acquire images of the impact and ejecta as it drifts past the asteroid. LICIACube will communicate directly with Earth, sending back images of the ejecta after the Dimorphos (Didymos B) flyby.
In a collaborating project, the European Space Agency is developing Hera, a spacecraft that will be launched to Didymos in 2024  — after DART's impact — to do a detailed reconnaissance and assessment. Hera would carry two CubeSats, APEX and Juventas.
|Host spacecraft||Secondary spacecraft||Remarks|
The mission's target is 65803 Didymos, a binary asteroid system in which one asteroid is orbited by a smaller one. The primary asteroid (Didymos A) is about 780 m (2,560 ft) in diameter; its small satellite Dimorphos (Didymos B) is about 160 m (520 ft) in diameter in an orbit about 1 km from the primary. DART will target the smaller asteroid, Dimorphos. Didymos is not an Earth-crossing asteroid, and there is no possibility that the deflection experiment could create an impact hazard.
- Asteroid impact avoidance
- B612 Foundation
- Don Quijote (spacecraft)
- Planetary defense against asteroids and comets
- The Spaceguard Foundation
- Adams, Elena; Oshaughnessy, Daniel; Reinhart, Matthew; John, Jeremy; Congdon, Elizabeth; Gallagher, Daniel; Abel, Elisabeth; Atchison, Justin et al. (2019). "Double Asteroid Redirection Test: The Earth Strikes Back". 2019 IEEE Aerospace Conference. pp. 1–11. doi:10.1109/AERO.2019.8742007. ISBN 978-1-5386-6854-2.
- "DART Launch Moves to Secondary Window". NASA. 17 February 2021. https://www.nasa.gov/feature/dart-launch-moves-to-secondary-window. This article incorporates text from this source, which is in the public domain.
- C19-009 (2019-04-12). "NASA Awards Launch Services Contract for Asteroid Redirect Test Mission". NASA. https://www.nasa.gov/press-release/nasa-awards-launch-services-contract-for-asteroid-redirect-test-mission. This article incorporates text from this source, which is in the public domain.
- Andone, Dakin (July 25, 2017). "NASA unveils plan to test asteroid defense technique". CNN. http://edition.cnn.com/2017/07/01/us/nasa-asteroid-defense-trnd/index.html.
- AIDA DART. Home page at APL.
- Asteroid Impact & Deflection Assessment (AIDA) study .
- DART at Applied Physics Laboratory Johns Hopkins University
- Planetary Defense: Double Asteroid Redirection Test (DART) Mission NASA 2017 This article incorporates text from this source, which is in the public domain.
- NASA plans to test asteroid deflection technique designed to prevent Earth impact G. Brown 4 July 2017
- Asteroid-deflection mission passes key development milestone 7 September 2018
- Northon, Karen (2019-04-11). "NASA Awards Launch Services Contract for Asteroid Redirect Test". NASA. http://www.nasa.gov/press-release/nasa-awards-launch-services-contract-for-asteroid-redirect-test-mission. This article incorporates text from this source, which is in the public domain.
- NASA is planning an asteroid deflection test mission in case the unthinkable happens Science Alert 5 July 2017
- DART: Home page at APL DART Spacecraft APL 2017
- "Impactor Spacecraft". NASA. 2021. https://dart.jhuapl.edu/Mission/Impactor-Spacecraft.php. This article incorporates text from this source, which is in the public domain.
- Cheng, A.F.; Michel, P.; Reed, C.; Galvez, A.; Carnelli, I. (2012). "DART: Double Asteroid Redirection Test". European Planetary Science Congress 2012. EPSC Abstracts. http://meetingorganizer.copernicus.org/EPSC2012/EPSC2012-935-1.pdf.
- Michel, P.; Cheng, A.; Carnelli, I.; A. Rivkin, C.; Galvez, A.; Ulamec, S.; Reed, C. (February 2015). "AIDA: Asteroid Impact and Deflection Assessment Mission Under Study at ESA and NASA". Observatoire de la Côte d'Azur 1829: 6008. Bibcode: 2015LPICo1829.6008M. https://www-n.oca.eu/michel/AIDA_Papers/Abstract_AstroRecon2015_PMichel.pdf. Retrieved 2015-03-29.
- Course corrector Adam Hadhazy Aerospace America October 2017
- NASA Pushes Through With Asteroid Deflection Mission That Could One Day Save Earth The Inquisitr 5 July 2017
- Asteroids have been hitting the Earth for billions of years. In 2022, we hit back. Andy Rivkin, The Johns Hopkins University Applied Physics Laboratory September 27, 2018
- Hera mission is approved as ESA receives biggest ever budget Kerry Hebden Room Space Journal 29 November 2019
- Kantsiper, Brian (2017). "The Double Asteroid Redirection Test (DART) mission electric propulsion trade". 2017 IEEE Aerospace Conference. pp. 1–7. doi:10.1109/AERO.2017.7943736. ISBN 978-1-5090-1613-6.
- Talbert, Tricia (2017-06-30). "Double Asteroid Redirection Test (DART) Mission". NASA. https://www.nasa.gov/planetarydefense/dart. This article incorporates text from this source, which is in the public domain.
- Cheng, Andrew F. (2018). "AIDA DART asteroid deflection test: Planetary defense and science objectives". Planetary and Space Science 157: 104–115. doi:10.1016/j.pss.2018.02.015. Bibcode: 2018P&SS..157..104C. https://www.astro.umd.edu/~dcr/reprints/cheng_pss157,104.pdf.
- Adams, Elena. "DART – Double Asteroid Redirection Test Status NASA's mission". Lunar and Planetary Institute. https://www.lpi.usra.edu/sbag/meetings/jan2019/presentations/Wednesday-PM/Adams.pdf.
- Cheng, A.F.; Michel, P.; Jutzi, M.; Rivkin, A.S.; Stickle, A.; Barnouin, O.; Ernst, C.; Atchison, J. et al. (2016). "Asteroid Impact & Deflection Assessment mission: Kinetic impactor". Planetary and Space Science 121: 27–35. doi:10.1016/j.pss.2015.12.004. Bibcode: 2016P&SS..121...27C.
- Kretschmar, Peter; Küppers, Michael (20 December 2018). "The CubeSat Revolution". ESA. https://www.cosmos.esa.int/documents/13611/1603502/20181220_cubesats.pdf#page=34.
- Adams, Elena; Oshaughnessy, Daniel; Reinhart, Matthew; John, Jeremy; Congdon, Elizabeth; Gallagher, Daniel; Abel, Elisabeth; Atchison, Justin et al. (2019). "Double Asteroid Redirection Test: The Earth Strikes Back". 2019 IEEE Aerospace Conference. pp. 1–11. doi:10.1109/AERO.2019.8742007. ISBN 978-1-5386-6854-2. ""In addition, DART is carrying a 6U CubeSat provided by Agenzia Spaziale Italiana (ASI). The CubeSat will provide imagery documentation of the impact, as well as in situ observation of the impact site and resultant ejecta plume""
- Fahnestock, E.; Yu, Y.; Cheng, A. F. (2018). "DART Impact Ejecta Simulation and Visualization for Fly-Along CubeSat Operational Planning". AGU Fall Meeting Abstracts 2018: P51A–07. Bibcode: 2018AGUFM.P51A..07F.
- Cheng, Andy (15 November 2018). "DART Mission Update". ESA. https://www.cosmos.esa.int/documents/1786001/1845930/4.+DART+Overview+%28A.+Cheng%29.pdf/da9935f1-74b7-9316-e9af-0fb2cc63197c.
- Bergin, Chris (January 7, 2019). "Hera adds objectives to planetary defense test mission". NASASpaceflight.com. https://www.nasaspaceflight.com/2019/01/hera-objectives-planetary-defense-mission/.
- Asteroids have been hitting the Earth for billions of years. In 2022, we hit back. Andy Rivkin The Johns Hopkins University Applied Physics Laboratory September 27, 2018
- A Low-Frequency Radar to Fathom Asteroids from Juventas Cubesat on HERA. Alain Herique, Dirk Plettemeier, Wlodek Kofman, Yves Rogez, Christopher Buck, and Hannah Goldberg; EPSC Abstracts, Vol. 13, EPSC-DPS2019-807-2, 2019. EPSC-DPS Joint Meeting 2019
- Exploration of the binary asteroid 65803 Didymos by the Hera mission. EPSC Abstracts, Vol. 13, EPSC-DPS2019-583-1; EPSC-DPS Joint Meeting 2019, 15-20 September 2019
- "CubeSats joining Hera mission to asteroid system". Space Daily. January 8, 2019. http://www.spacedaily.com/reports/CubeSats_joining_Hera_mission_to_asteroid_system_999.html.
- Michel, Patrick; Kueppers, Michael; Sierks, Holger; Carnelli, Ian (26 April 2017). "European component of the AIDA mission to a binary asteroid: Characterization and interpretation of the impact of the DART mission". Advances in Space Research 62 (8): 2261–2272. 18 December 2017. doi:10.1016/j.asr.2017.12.020. https://hal-insu.archives-ouvertes.fr/insu-01667223/file/Michel_20938.pdf.
Original source: https://en.wikipedia.org/wiki/ Double Asteroid Redirection Test. Read more