WASHINGTON — NASA Administrator Charles Bolden told a congressional panel that a captured asteroid is a worthy destination for human explorers, despite the insistence from the chairman of the U.S. House Science, Space and Technology Committee that the lunar surface is a better choice.

In an April 24 hearing of the House Science space subcommittee about NASA’s 2014 budget request, Rep. Lamar Smith (R-Texas) — the full committee’s chairman — repeatedly asked Bolden which would better prepare the agency to visit Mars: a mission to the lunar surface, which Smith supports strongly, or bringing a small asteroid back to lunar space for astronauts launched aboard the Space Launch System (SLS) and Orion Multi-Purpose Crew Vehicle to visit. 

“I don’t think either would be better,” Bolden told Smith. “They both are good. … The one that is executable in today’s budget environment is an asteroid.”

Smith continued to press Bolden about a lunar return.

“There’s a lot more to do there than what we’ve done so far,” Smith said, referring to the limited lunar rock caching done by Apollo astronauts in the 1970s. “If various experts said, ‘The Moon [is better],’ would you heed their advice?”

“We get expert advice all the time,” Bolden replied. “It is impossible to heed the advice of all experts.”

As part of its 2014 budget request for NASA, the White House is proposing the space agency locate a small asteroid, one about 10 meters in diameter, and bring it back to lunar space where it could be visited by astronauts by 2025. NASA estimates the mission will cost about $1 billion and has requested $105 million in 2014 for early concept work. After Bolden defended the White House’s proposal, the subcommittee took a recess. 

When lawmakers returned for the second half of the NASA budget hearing, Bolden said a brief private chat with Smith had not altered his thinking about asteroid retrieval.

“The chairman told me to think about it again and come out and say, ‘Forget about the asteroid mission.’ I’m not ready to do that yet,” Bolden said. “There is a decided advantage in an asteroid retrieval mission on the road to Mars.”

For one, Bolden said, landing on the Moon would require NASA to spend an estimated $8 billion to $10 billion on a landing craft. Bolden said that is the estimated price of the Altair lunar lander Northrop Grumman was designing under the Constellation program. The White House canceled Constellation in 2010 saying it was unaffordable.

Meanwhile, a Republican lawmaker whose district includes the Marshall Space Flight Center — which is managing the SLS project — threw his support behind the asteroid-capture mission.

“I think that’s a good direction to go,” said Rep. Mo Brooks (R-Ala.). “I think it recognizes the risk to our country and our world. … I think it’s another reason why we need the Space Launch System to have the capability of doing whatever needs to be done, so I see it as a hand-in-glove effort.”

Dan Leone is the NASA reporter for SpaceNews, where he also covers other civilian-run U.S. government space programs and a growing number of entrepreneurial space companies. He joined SpaceNews in 2011.Dan earned a bachelor's degree in public communications...