NASA’s proposed mission to capture an asteroid is being scaled back, though the space agency promises the initiative can still be a proving ground for new technology we’ll need to eventually reach Mars and beyond.
Officials have announced that the initial Asteroid Redirect Mission (ARM) to redirect an entire asteroid back to the moon and place it into stable orbit will instead focus on robotically capturing a large boulder from an asteroid and placing it into orbit. Kind of the same idea, just on a smaller scale. The plan is for a robotic spacecraft to pluck a boulder from an asteroid and carry it back to the moon, where future astronauts will eventually study it during a spacewalk.
Though it seems a bit random to spend so much time and energy on snagging an asteroid, NASA Associate Administrator Robert Lightfoot said the technology developed for the initiative could prove critical for future space exploration. One such tech, advanced Solar Electric Propulsion (SEP), converts sunlight to electrical power through solar arrays and could be the most efficient way to move large cargo through space:
"The Asteroid Redirect Mission will provide an initial demonstration of several spaceflight capabilities we will need to send astronauts deeper into space, and eventually, to Mars," Lightfoot said. "The option to retrieve a boulder from an asteroid will have a direct impact on planning for future human missions to deep space and begin a new era of spaceflight."
NASA plans to finalize the specific asteroid for the mission no earlier than 2019, then take another year before launching the robotic spacecraft. NASA has identified three valid candidates for the mission so far: Itokawa, Bennu and 2008 EV5. The agency expects to identify one or two additional candidates each year leading up to the mission, and they’ll spend the next few years studying their orbits and composition before making a final selection.