Even though the planned Asteroid Redirect Mission remains controversial, NASA is proceeding apace with undertaking it. The space agency announced Thursday that it had awarded a number of companies small concept contracts worth a total of $4.9 million aimed toward asteroid capture and prospecting. It has also identified a possible target asteroid, 2011 MD.
NASA chose to fund 18 proposals to a number of companies and organizations, including the Planetary Society, Planetary Resources, Deep Space Industries, Boeing, and Lockheed Martin. The six month studies range from secondary payloads that might be launched on the ARM mission to tools like drills and grasping arms that could be used during and after an asteroid capture.
In the meantime the hunt for a target asteroid proceeds apace. NASA's Spitzer Space Telescope recently examined 2011 MD,. A near Earth object that is six meters in size and has a low density, the same as water. This suggests to NASA scientists that the object is really a collection of boulders held together by gravity. It could also be a single smaller rock surrounded by a cloud of particles. In either case the ARM mission could capture it and move it to lunar orbit.
NASA also plans to decide by the end of 2014 whether it wants to have the ARM mission capture a single small asteroid or retrieve a boulder from the surface of a larger asteroid. In either case it intends to send the ARM mission, a robot propelled by a solar electric rocket, in 2019 to rendezvous with the rock, grab it, and then move it to lunar orbit. Later, perhaps as early as 2021, NASA plans to send an Orion spacecraft launched by a heavy lift Space Launch System to the captured asteroid with a crew of astronauts.
The ARM has come under a great deal of criticism from various quarters, most recently in a report by the National Research Council. NASA intends the ARM to be an intermediate mission to take place before a human voyage to Mars. The NRC report strongly hinted that either a return to the moon or a visit to an asteroid “in its native orbit” would be better precursor missions to a Mars voyage.