The NRC report added that there appears to be continued enthusiasm for a mission to the moon but not for an asteroid mission, although there is both U.S. and international interest in robotic missions to asteroids.
But the view that a manned flight to a near-Earth object (NEO) is a dubious destination doesn’t settle well in some quarters.
Bring the asteroid to the astronauts
"I agree with the findings in the NRC report that NASA has a long way to go to fulfill the Obama goal of an asteroid mission by 2025," said former astronaut Tom Jones, author of the upcoming book, "Mission: Asteroid."
Jones told SPACE.com that NASA has not taken any major steps, starting with a search for near-Earth asteroid (NEA) targets, necessary to achieve that goal. The agency has so little money that it can’t afford its own asteroid search program, relying instead on a private asteroid-hunting telescope commissioned by the B612 Foundation. NASA's Orion deep-space vehicle and large booster programs won't fly with a crew until after 2020, given current budgets and schedules, he said.
"The best way for NASA to reach both its asteroid goal and to launch humans into translunarspace — beyond the moon — is to use a robot spacecraft to retrieve and return to a safe lunar orbit a small, 500-ton asteroid," Jones said. "Near the Earth-moon L2 point, astronauts and robot probes can explore and dissect this asteroid for science and commercial-scale resources … water being the most valuable."
Bringing the asteroid to the astronauts, Jones said — as described by the Keck Institute for Space Studies team in 2012 — "could jump-start an entire industry between the Earth and the moon, using the energy and raw materials of space to enable everything from robotic probes to the planets, to eventual moon and Mars surface exploration," he said.
Foundation of self-sustainability
"U.S. strategic goals for human space activity need to be long-term. We should have continuous operational reach in near-Earth space, regular access to the surface of the moon, and regular access to Mars," said Mark Sykes, director of the Planetary Science Institute in Tucson, Ariz. He is also the chair of NASA’s Small Bodies Assessment Group.
"All of this requires building space-based infrastructure on a foundation of self-sustainability. Accessing and utilizing resources available on near-Earth objects, particularly water for fuel, life-support and shielding, is the cornerstone and is critical to achieving any of these goals," Sykes told SPACE.com.
Sykes said it would make sense to send a piloted mission to oversee the automated emplacement and startup of a resource recovery facility on a near-Earth object.