Scheduled to begin in 2020, the purpose of the ARM is to test new technologies and techniques that would be needed for later manned deep space missions while learning more about asteroids and how to defend the Earth against them. This involves sending a robotic spacecraft to collect a boulder from a near-Earth asteroid, then return it to lunar orbit, where a later manned mission will rendezvous to retrieve samples.

The ARM will begin with an unmanned Asteroid Redirect Vehicle being sent to a target asteroid, which has yet to be selected. The collector spacecraft will travel to the asteroid on a multi-year trajectory using Solar Electric Propulsion (SEP). This uses solar panels to power ion thrusters that provide a very low, constant thrust for years on end by charging xenon atoms and accelerating them. The system is currently being used on the Dawn mission and NASA hopes that it could one day be used to preposition supply craft for a Mars mission.