It is not about Yes but when a dangerously large asteroid ends up on a collision course for Earth, and NASA wants to be ready. The double asteroid redirection test (DART) has been in development for several years, and now has a real launch date with the award of a contract to SpaceX. DART will head to space to destroy an asteroid in June 2021 aboard a Falcon 9 rocket.
DART, part of NASA's planetary defense research initiative, is under development at the Applied Physics Laboratory at Johns Hopkins University. One of the most promising proposals to deflect an asteroid is with a kinetic impactor. If you hit the object with something dense and fast, it may be possible to move your trajectory away from an impact. However, there is much we do not know about asteroids, even in recent missions to study them closely. DART aims to learn how asteroids are likely to behave when struck with a kinetic impactor.
The NASA agreement with SpaceX has a much lower price than similar launches. It will cost the agency only $ 61 million, including all support and related services. That's cheap even by the standards of a Falcon 9 launch, which are less expensive than competitive rockets because they are completely reusable. A similar SpaceX launch in late 2020 for the Sentinel-6A satellite will cost NASA $ 97 million, for example.
The mission will use an impactor the size of a refrigerator against an object called Didymos. Technically, Didymos are two objects that orbit each other. Didymos A is approximately 2,600 feet (800 m) in diameter, while Didymos B (sometimes called Didymoon) is only 560 feet (170 m) in diameter. The launch of 2021 gives DART driven impulse ions enough time to meet Didymos A and B as they pbad a few million miles from Earth in October 2022.
A SpaceX Falcon 9 ready for launch.
The impactor will collide with Didymos B at a speed of more than six kilometers per second. That should impart a lot of kinetic energy to the small asteroid, allowing scientists to measure the effect of the impact by observing how its orbit changes.
No one expects Didymoon to fly into deep space, but the best scenario is for his orbit to change. That would indicate that kinetic impactors can deflect an asteroid. However, it is also possible that the asteroid can deform and dissipate much of the kinetic energy, in which case we should focus on other ways of redirecting the asteroids.