This is an excellent idea to go to a larger Earth threating asteroid, but much less expensive to do a robotic sample return first then a manned mission to do a selected sample return from various locations and possibly include a drilling to get some samples from deeper inside the asteroid.
NASA’s Garver Floats Idea of Capturing Larger Asteroid
One way to expand public and congressional support for NASA’s proposed Asteroid Redirect Mission would be to target a larger asteroid than previously proposed, NASA Deputy Administrator Lori Garver said July 26.
Speaking at the Space Frontier Foundation’s NewSpace conference in San Jose, Calif., Garver said growing public, congressional and private sector interest in identifying asteroids that pose a threat to human populations could provide the impetus for NASA to send astronauts to land on and carve off a piece of a large asteroid near Earth. Garver declined to comment on the size of the proposed asteroid destination.
“If we are saying this mission is going to help us protect the planet, maybe we should consider going to a larger asteroid so we can drive specifically the observations for larger asteroids that are actually threats to us,” Garver said. “By taking a piece of that asteroid and moving it, we might be able to get answers to some of the questions of folks who believe this [mission as currently envisioned] is not as meaningful as we believe it is.”
NASA outlined a proposal in April to capture an asteroid 7 to 10 meters in diameter and move it to lunar space to provide a destination for the Orion Multi-Purpose Crew Exploration Vehicle it is building to carry astronauts into deep space starting in 2021.