NASA to Smash Satellite into Asteroid in 2020
by Ryan Whitwam
Earth has been hit by large asteroids and comets many times in the past, and it’s a matter of when rather than if it happens again. There weren’t any humans on Earth for the large impacts in the past, some of which led to mass extinctions. That’s something everyone can agree we should try to avoid, but how? The technology to deflect an asteroid impact is currently beyond us, but NASA is preparing to test a potential solution. The Double Asteroid Redirection Test (DART) program has entered the design phase, and could head out to a passing asteroid as soon as 2022.
The design process is being headed by researchers from the Johns Hopkins Applied Physics Laboratory. The goal is to use a refrigerator-sized object to smash into and deflect an asteroid from Earth. Of course, there’s no way such a mission could stop an asteroid that’s poised to smack into the planet in the near future. However, a little nudge early enough might alter an object’s orbit and cause it to miss an impact with Earth.
The target for the DART mission is an asteroid known as Didymos. This is technically two asteroids, called Didymos A and Didymos B (or Didymoon). Didymos A is about 2,600 feet (800m) in diameter, while Didymos B is a mere 560 feet (170m) across. Didymos B orbits A, which makes this an ideal system for testing the effect of a kinetic impact technique.
DART was originally conceived of as a part of the Asteroid Impact and Deflection Assessment (AIDA), operated in cooperation with the European Space Agency. However, the future of Europe’s side, known as the Asteroid Impact Mission (AIM), is in doubt. The European half of the mission would include a lander that sets down on the surface of Didymos B, then waits for DART to show up and collide with it. AIM could collect precise seismic and force data, then beam it back to Earth. NASA is moving ahead with DART, hoping to use ground-based observation to measure the effects of impact.
Time is a factor here. The team must complete design and construction of the probe in time for a 2020 launch. That’s necessary to make the 2022 rendezvous with Didymos, when it passes within about 6.8 million miles of Earth. If the mission is a success, it could form the basis for a future system to deflect asteroid before they hit us. The key, however, will be detecting dangerous objects before they’re too close.
Originally published at www.extremetech.com on July 5, 2017.