An artist's impression of an Ares V rocket, NASA's planned heavy-duty launcher, entering space.
The White House has ordered a complete outside review of NASA's manned space program, including plans to return astronauts to the moon.
Officials want a report from an independent panel by August. White House science adviser John Holdren said Thursday that the new panel will look at the design of new spacecraft to replace the space shuttle and go to the moon, as well as consider possible alternatives to the current design.
Holdren said it will also examine the five-year gap between the shuttle's retirement and the new moon vehicles, with the first new space capsule flying in 2015.
During that time, starting in late 2010, NASA would have to rely on the Russians for space travel. The review will look at extending NASA's use of the multibillion-dollar international space station beyond 2016.
NASA has already spent $6.9 billion on its plan to return to the moon, which then-President George W. Bush unveiled as a response to the 2003 space shuttle Columbia accident.
In a letter to NASA, Holdren wrote that because of the magnitude of the manned space program's ambitions and its expense, "it would be only prudent for the new Administration to review the array of challenges in the program."
"It's a thorough review," NASA acting administrator Chris Scolese told The Associated Press.
"Clearly if we are on the wrong path, we should change," Scolese said at a NASA budget briefing Thursday. "If you are asking me if I think we're on the wrong path, no, I don't."
The current plan involves two types of rockets, called Ares.
The smaller Ares rocket would carry an Orion capsule with astronauts to the moon or the space station.
The larger Ares rocket would be unmanned and carry heavy equipment to space. Key tests of the Ares rockets are scheduled for later this year.
While the review is being done, NASA will continue the Ares and Orion programs.
The space agency is spending about $300 million a month on those plans, but Scolese said it doesn't make sense to put moon spending on hold in the meantime because that would mean an even longer gap between the end of the space shuttle and the first flight of a new spaceship.
Former NASA associate administrator Scott Pace, who was part of the moon mission planning during the Bush administration, said "it's necessary" to look at the moon program a second time.
While they may find some areas that can be improved, in general the design is right, he said.
The review of NASA's signature program was part of President Barack Obama's 2010 budget rollout. NASA's proposed $18.7 billion budget includes an extra space shuttle flight for the end of next year, one that had been cut by the Bush administration.
That new flight will carry a scientific device that would be attached to the space station and search out unusual particles in the universe — antimatter, dark matter and cosmic rays.
The review team will be headed by former Lockheed Martin CEO Norman Augustine. He headed a major examination of NASA's plans in 1990.