STEVE INSKEEP, host:
Well, the shuttle Atlantis is scheduled to land tomorrow morning. This final mission is the latest milestone for American manned spaceflight.
MARY LOUISE KELLY, host:
Mercury capsules got Americans into space half a century ago.
INSKEEP: The Gemini program added to their accomplishments.
KELLY: The Apollo program took Americans to the moon.
INSKEEP: And the shuttle aspired to make orbiting the Earth ordinary.
KELLY: Now NASA leaders say they're getting ready to build a new vehicle to send astronauts exploring deep into space.
INSKEEP: But as NPR's Nell Greenfieldboyce reports, some experts doubt this vision of NASA's future will get off the ground.
NELL GREENFIELDBOYCE: To understand the big question mark looming over NASA's future, let's go back to 2004, the year after the space shuttle Columbia disaster. President George W. Bush declared that NASA would finish building the International Space Station and then retire its aging shuttles.
President GEORGE W. BUSH: It is time for America to take the next steps. Today I announce a new plan to explore space and extend a human presence across our solar system.
GREENFIELDBOYCE: NASA would build a new capsule and a pair of rockets. First, a rocket to take astronauts up to low Earth orbit, where the station is, and then a bigger rocket, to return to the moon by 2020.
The new program was called Constellation. For years that was the post-shuttle plan. But after President Obama took office, he ordered a review. A panel of experts said despite the billions already spent, Constellation had been under-funded, was behind schedule, and couldn't reach its goals without a lot more money.
Last year, President Obama said let's kill it.
President BARACK OBAMA: The bottom line is, nobody is more committed to manned space flight, to human exploration of space, than I am. But we've got to do it in a smart way.
GREENFIELDBOYCE: He said a smarter plan was to forget about a rocket for routine flights to the station. NASA should turn that work over to commercial companies. They'd develop space taxis. NASA would just buy rides. This would let the agency focus on designing a big new rocket for deep space missions, though it wouldn't be the rocket planned under Constellation, and it wouldn't first aim for the moon. An asteroid was the new goal.
The loss of Constellation was a shock to many NASA workers. Shuttle launch director Mike Leinbach recently expressed those feelings to his team at Kennedy Space Center in Florida. The launch controllers had just completed a practice countdown for the final mission and Leinbach spoke over their communications link.
Mr. MIKE LEINBACH (Shuttle Launch Director, NASA): Throughout the history of the manned space flight program, we've always had another program to transition into - from Mercury to Gemini to Apollo, Apollo-Soyuz test program, to Skylab, and then the shuttle - we've always had something to transition into. And we had that, and it got cancelled and now we don't have anything, and I'm embarrassed that we don't.
GREENFIELDBOYCE: He said, as a senior NASA manager he'd like to apologize.
Mr. LEINBACH: You know, the end of the shuttle program is a tough thing to swallow, and we're all victims of poor policy out of Washington, D.C., both at the national(ph) level and the executive branch of the government.
GREENFIELDBOYCE: These blunt words got applause. The audio got posted on websites. Not surprisingly, leaders in Washington don't share those views.
Former astronaut Charles Bolden is the head of NASA.
Mr. CHARLES BOLDEN (NASA): Mike is an incredibly talented person and I think he is to be touted for the job that he has done as the launch director down there. I would disagree with him in terms of there is no program going forward.
GREENFIELDBOYCE: Bolden says the future is robust.
Mr. BOLDEN: We will begin to fly commercial spacecraft taking cargo to the International Space Station as early as hopefully the first quarter of 2012, next year.
GREENFIELDBOYCE: And until those commercial providers can carry people as well as cargo, astronauts will ride on Russia's rockets.
Mr. BOLDEN: American astronauts will continue to be going to the International Space Station. We just named a new crew about two weeks ago, and we will continue to name crews until 2020.
GREENFIELDBOYCE: Plus, he says, NASA is designing the big new rocket - the one that will carry a crew capsule out beyond the station, to go exploring.
Mr. BOLDEN: It'll be a system that the nation will be proud of, that will enable us to get humans beyond low Earth orbit and eventually on to Mars.
GREENFIELDBOYCE: Congress recently told NASA to build that system by 2016, and to use existing industry contracts as much as possible. Senator Bill Nelson of Florida flew on the space shuttle. He thinks that building the big new rocket is what NASA needs to do, no matter where it's going next.
Senator BILL NELSON (Democrat, Florida): Maybe it's going to be an asteroid, as the president suggested, for 2025. It's possible we may go back to the moon. There may be other destinations. All of these are going to develop as we develop technology. But the first thing we have to have is a big rocket that can get all of these different components and refueling up into Earth orbit.
GREENFIELDBOYCE: But given that NASA just canceled its first post-shuttle rocket program, this latest one is being greeted with skepticism.
Mr. JEFF GREASON (XCOR Aerospace): I think the most likely outcome is that the big rocket will be canceled, and the only uncertainty is will it be canceled shortly before or shortly after it starts flying.
GREENFIELDBOYCE: That's Jeff Greason. He's an executive with a rocket company called XCOR Aerospace. He served on the committee that reviewed NASA's options for the president. He says, look, NASA's rocket plan is too expensive in an era of shrinking budgets. He thinks the space program needs to rethink what the goals of exploration are and how to realistically accomplish them.
Mr. GREASON: The ultimate purpose of space, in my mind, is to open a frontier for humanity. That resonates. And many people, even going back to the Apollo era, supported the space program because they thought that's what it was about.
GREENFIELDBOYCE: What do you think it's about now?
Mr. GREASON: I don't think it's about anything right now.
GREENFIELDBOYCE: He says decision-makers should consider the lessons of the soon-to-be-retired shuttle.
Mr. GREASON: It was a very impressive machine. And the people who built it, you know, should be proud of it. But I also think that in some ways it warns us of the trap that we can get into when we get carried away by the desire to build something, as a nation, without stopping to ask the question of what's the purpose of it.
GREENFIELDBOYCE: He says maybe NASA doesn't need to build its own rocket for exploring deep space. It could find ways of using commercially available rockets, just like it's doing closer to home, for getting to the space station. Private companies are seizing the opportunities that NASA has opened up. Commercial capsules could be taking people to the station in just a few years.
Astronaut Chris Ferguson is the commander of the final shuttle mission. He says once the shuttle lands for the last time...
Mr. CHRIS FERGUSON (Astronaut): The next person that flies a U.S. rocket to low Earth orbit probably will not have a NASA badge on, will probably have a badge that has Boeing or SpaceX or Sierra Nevada. Which is kind of an interesting concept, if you think about it.
GREENFIELDBOYCE: And it's a concept that's supposed to free up NASA for exciting new missions. But after 30 years of flying the shuttle, it's not clear what those should be.
Nell Greenfieldboyce, NPR News.