NASA’S First Asteroid Deflection Mission Enters Next Design Phase
The first-ever mission to demonstrate an asteroid deflection technique for planetary defense -- the Double Asteroid Redirection Test (DART) -- is moving from concept development to preliminary design phase, following NASA’s approval on June 23.
While current law directs the development of the DART mission, DART is not identified as a specific budget item in the Administration’s Fiscal Year 2018 budget.
The target for DART is an asteroid that will have a distant approach to Earth in October 2022, and then again in 2024. The asteroid is called Didymos -- Greek for “twin” -- because it’s an asteroid binary system that consists of two bodies: Didymos A, about one-half mile (780 meters) in size, and a smaller asteroid orbiting it called Didymos B, about 530 feet (160 meters) in size. DART would impact only the smaller of the two bodies, Didymos B.
The Didymos system has been closely studied since 2003. The primary body is a rocky S-type object, with composition similar to that of many asteroids. The composition of its small companion, Didymos B, is unknown, but the size is typical of asteroids that could potentially create regional effects should they impact Earth.
After launch, DART would fly to Didymos, and use an on-board autonomous targeting system to aim itself at Didymos B. Then the refrigerator-sized spacecraft would strike the smaller body at a speed about nine times faster than a bullet, approximately 3.7 miles per second (6 kilometers per second). Earth-based observatories would be able to see the impact and the resulting change in the orbit of Didymos B around Didymos A, allowing scientists to better determine the capabilities of kinetic impact as an asteroid mitigation strategy. The kinetic impact technique works by changing the speed of a threatening asteroid by a small fraction of its total velocity, but by doing it well before the predicted impact so that this small nudge will add up over time to a big shift of the asteroid’s path away from Earth.
DART is being designed and would be built and managed by The Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. The project would be overseen by the Planetary Missions Program Office at Marshall Space Flight Center in Huntsville, Alabama. DART also is supported by teams from the Goddard Space Flight Center, Greenbelt, Maryland; Johnson Space Center, Houston, Texas; and the Jet Propulsion Laboratory, Pasadena, California.
Source:
NASA Planetary Defense Coordination Office
NASA DART Mission