Back to the moon.

Byline: The Register-Guard

NASA has a Goldilocks problem: The plan announced by the space agency Monday to send astronauts to the moon in 2020, and establish a permanent lunar base by 2024, is too big, and it's too small.

It's too big because sending regularly scheduled manned spacecraft to the moon and supporting long-term residents at a lunar base would be expensive. NASA intends to retire its space shuttle fleet by 2010, and also envisions a smaller role for the United States in the International Space Station. With these expenses behind it, NASA claims the moon base program can fit within the agency's current annual budget of $17 billion. Yet NASA hasn't put a price tag on the moon mission, and it seems likely that most or all other space exploration programs would be squeezed out.

It's too small because NASA mostly would be replicating a success it achieved nearly four decades ago. The agency would use launchers similar to those that took American astronauts to the moon six times from 1969 through 1972. Despite its reliance on off-the-shelf technology, the second manned moon program would take about twice as long to reach its goal as the first - not exactly a giant leap for mankind.

The cost of the lunar program guarantees opposition in Congress, while its limited ambition would encounter resistance from influential members of the aerospace community, who see the moon as a detour on the way to Mars. The fourth planet is much harder to reach but is potentially a far more rewarding destination, offering most of the raw materials needed to sustain a long-term human presence.

The fact that astronauts have visited the moon already is not the only aspect of NASA's announcement that induces a sensation of deja vu. The first President Bush declared in 1989 that the United States should build a manned lunar base. The current President Bush proposed a trip to Mars two years ago, perhaps with the moon as a stopping point. Commitments to manned space exploration have proved easy to make, but difficult to sustain.

NASA needs to offer a compelling reason to return to the moon - proving that it can be done is not enough. Otherwise, the lunar base will suffer in competition for funding and for a place in people's imaginations. Both money and imagination are essential fuel for a decades-long undertaking in space.