In a hangar here at the Johnson Space Center, engineer Lori Hanson shows off a model of the agency's pride and joy: the new spaceship NASA is designing to carry astronauts back to the moon.
It will be bigger than the Apollo capsule, she says, "because the mission is very different from Apollo." For the first time, NASA will build a base on the moon, where humans could live for six months at a stretch.
Those who keep tabs on NASA's fortunes worry that the agency's plan to return Americans to the moon in a decade won't amount to more than a cluster of plywood frames in a hangar. As NASA marks its 50th anniversary Wednesday, space experts say NASA is adrift, its future disturbingly murky.
The space shuttle is due to retire in two years. Its successor, beset by budget and technical problems, won't fly until 2015 at the earliest, creating a stretch of at least five years when the United States will have no way to launch humans into orbit.
"It's a rather unfortunate time to be celebrating a 50th anniversary," says space historian Joan Johnson-Freese of the Naval War College. "Right now, we're at best at a plateau, if not — I hate to say this — heading downwards."
The space agency was born Oct. 1, 1958, at the decree of Congress. Less than 11 years later, it landed the first man on the moon, a feat that has yet to be equaled by any other nation.
Since then, NASA has sent robots to every corner of the solar system and built a spaceship, the shuttle, more versatile than any in history. It also lost astronauts — 14 died in two shuttle accidents — and the nation's attention.
"I've seen NASA struggle with how … we get back to an Apollo kind of excitement," says former space-agency official Ray Colladay. "It's a middle-aged bureaucracy now."
President Bush tried in 2004 to reinvigorate NASA, directing the agency to send astronauts back to the moon by 2020 and to start planning to send humans to Mars. Bush also promised an infusion of cash to pay for it all, but the full sum failed to materialize.
Even one of the authors of Bush's moon plan says the president's space legacy is in question.
"The agency is at a crossroads," says Bretton Alexander, a former White House aide now at the X Prize Foundation, a non-profit group that funds technology contests. "The next administration has a big decision to make about which direction (NASA) will go."
Alexander and others cite a host of problems dogging the space agency as it prepares to celebrate its 50th birthday:
• What to do with the space shuttle. At Bush's direction, NASA plans to retire the shuttle in mid-2010, but there's support in Congress to keep the shuttle flying. That could cost $4 billion a year. NASA needs that money to build the new moon vehicle.
The shuttle has had two deadly accidents in 124 flights. NASA chief Michael Griffin told The Orlando Sentinel this month that if the shuttle's life is extended for five more years, there would be a one-in-eight risk of losing astronauts in that period.
• How to get astronauts to the International Space Station, an orbital lab funded largely by the U.S. After the shuttle retires, NASA hopes to use Russian craft to carry U.S. crews to the station. Purchase of the Russian ships requires congressional approval, which has yet to be granted.