NASA is developing a first-ever robotic mission to visit a large near-Earth asteroid, collect a multi-ton boulder from its surface, and redirect it into a stable orbit around the moon. Once it’s there, astronauts will explore it and return with samples in the 2020s.
(NASA's Asteroid Redirect Mission video)
NASA has identified multiple candidate asteroids and continues the search for one that could be redirected to near the moon in the 2020s. Since the announcement of the Asteroid Initiative in 2013, NASA’s Near-Earth Object Observation Program has catalogued more than 1,000 new near-Earth asteroids discovered by various search teams. Of those identified so far, four could be good candidates for ARM. Scientists anticipate many more will be discovered over the next few years, and NASA will study their velocity, orbit, size and spin before deciding on the target asteroid for the ARM mission.
The Asteroid Redirect Mission is one part of NASA’s Asteroid Initiative. The initiative also includes an Asteroid Grand Challenge, designed to accelerate NASA’s efforts to locate potentially hazardous asteroids through non-traditional collaborations and partnerships. The challenge could also help identify viable candidates for ARM.
NASA plans to launch the ARM robotic spacecraft at the end of this decade. The spacecraft will capture a boulder off of a large asteroid using a robotic arm. After an asteroid mass is collected, the spacecraft will redirect it to a stable orbit around the moon called a “Distant Retrograde Orbit.” Astronauts aboard NASA's Orion spacecraft, launched from a Space Launch System (SLS) rocket, will explore the asteroid in the mid-2020s.
Robert Heinlein wrote about capturing an asteroid and changing its orbit in his still excellent 1939 short story Misfit:
Eighty-eight swung some millions of miles further around the sun. The pock-marks on her face grew deeper, and were lined with durite, that strange close-packed laboratory product which (usually) would confine even atomic disintegration. Then Eighty-eight received a series of gentle pats, always on the side headed along her course. In a few weeks' time the rocket blasts had their effect and Eighty-eight was plunging in an orbit toward the sun.
When she reached her station one and three-tenths the distance from the sun of Earth's orbit, she would have to be coaxed by another series of pats into a circular orbit. Thereafter she was to be known as E-M3, Earth-Mars Space Station Spot Three.
(moving an asteroid)