STEVE INSKEEP, Host:
To some lawmakers, President Obama's new plan for NASA sounds like a road to nowhere. His proposed budget would kill a major NASA rocket program aimed at returning astronauts to the moon. The NASA chief is on Capitol Hill this week, trying to explain where NASA is headed. NPR's Nell Greenfieldboyce reports.
NELL GREENFIELDBOYCE: Charlie Bolden is a former astronaut and the head of NASA. Yesterday, he sat alone at a table under a crystal chandelier in a Senate hearing room, listening to lawmakers express some major concerns about NASA's future. One of the big ones: what is the ultimate destination for tomorrow's astronauts.
Senator Bill Nelson is a Democrat from Florida who once flew on the space shuttle. He suggested that NASA heed some wise words from a famous American philosopher, Yogi Berra.
BILL NELSON: You've got to be very careful if you don't know where you're going, because you might not get there.
GREENFIELDBOYCE: He said NASA's proposed budget devotes a lot of money to research and developed new technologies, but without a specific goal.
NELSON: The U.S., this senator fears, is going to be on the sidelines while other countries continue to make incremental progress toward destinations like the moon.
GREENFIELDBOYCE: This concern was echoed by Republican Senator David Vitter from Louisiana. He noted that NASA's greatest achievements came back when it was challenged by President Kennedy to land a man on the moon and return him safely by the end of the decade.
DAVID VITTER: President Kennedy didn't say we're going to spend several billion dollars and do some really neat R and D.
GREENFIELDBOYCE: In response, NASA Administrator Bolden said that there is an ultimate goal - and that's Mars. Trouble is, he says there's lots of new technology needed before anyone could realistically contemplate a manned Mars mission.
CHARLIE BOLDEN: If you gave me an infinite pot of money, I could not get a human to Mars within the next 10 years - because there are just some things that we don't know.
GREENFIELDBOYCE: He said the new budget would keep astronauts going to space by providing funds to extend the life of the International Space Station. It would also support efforts by private firms to develop space taxis to take astronauts up. And NASA may end up visiting the moon, or maybe an asteroid, before aiming for Mars.
But Bolden said for years NASA's moon rocket program had been under-funded, so its vision of returning astronauts to the lunar surface by 2020 just wasn't feasible.
BOLDEN: Somebody once told me a vision without resources is a hallucination. If you look at where we were prior to the 2011 budget, we were living a hallucination.
GREENFIELDBOYCE: To that, Senator Vitter has this comeback?
VITTER: If a vision without resources is a hallucination, resources without vision is a waste of time and money.
GREENFIELDBOYCE: He vowed to fight the current administration's proposals with, quote, "every ounce of energy I have." And said he felt there was bipartisan support in Congress for that effort.
Nell Greenfieldboyce, NPR News.