NASA (search) hopes to return astronauts to the moon by 2018, nearly a half-century after men last walked the lunar surface, by using a distinctly retro combination of space shuttle and Apollo rocket parts.

The space agency presented its lunar exploration plan to the White House on Wednesday and on Capitol Hill on Friday. An announcement is set for Monday at NASA headquarters in Washington.

The fact that this successor to the soon-to-be-retired shuttle relies so heavily on old-time equipment, rather than sporting fancy futuristic designs, "makes good technological and management sense," said John Logsdon, director of George Washington University's space policy institute.

"The emphasis is on achieving goals rather than elegance," said Logsdon, who along with other members of the Columbia Accident Investigation Board (search) urged NASA to move beyond the risky, aging shuttles as soon as possible.

"It has several elements to it. One is to say that the people who did Apollo were pretty smart," Logsdon said Friday. Depending on advanced, unproven technology would slow everything down and raise the costs, which will be high anyway, he noted.

The crew exploration vehicle's first manned trip will be to low-Earth orbit, probably no earlier than 2012, leaving up to a two-year gap between the last shuttle flight and the debut of its successor.

In January 2004, just five months after the Columbia accident board's report, President Bush called for the retirement of the space shuttles by 2010 and the creation of the crew exploration vehicle for ferrying astronauts to the international space station and ultimately to the moon and Mars.

His main overriding goal: to land astronauts on the moon by 2020.

In a speech at a California aerospace conference two weeks ago, NASA Administrator Michael Griffin (search) said the new spacecraft will build upon the proven designs and technologies used in the Apollo moon and shuttle programs — "while having far greater capability."

There would be two rockets, one for astronauts and their exploration vehicle and the other for cargo, the propulsion system and the lunar lander.

The idea would be to launch the crew exploration vehicle on the smaller of the new rockets, which would still be taller than the 184-foot shuttle. The crew vehicle would be perched on top like an old-style Apollo capsule.

Once in orbit around the Earth, the capsule would hook up with the lunar lander and moon-propelling rocket parts launched separately on a much bigger rocket closer in height to Apollo's 363-foot Saturn 5, and take off for the moon.

These new rockets would consist of space shuttle booster rockets, engines and fuel tanks, with the payload — human or not — always on top for a safer ride. They also would use some of the same type of Saturn 5 engines that propelled astronauts to the moon.

Using shuttle parts will ease the work force transition between the two programs, Logsdon said, and require no major rebuilding of the Kennedy Space Center (search) launch site.

In his speech, Griffin spoke of a system that will take four astronauts to the surface of the moon — rather than the two-man landing teams of Apollo — and allow them to remain there a full week instead of just a few days. Longer stays and a real outpost would follow.

The crew exploration vehicle would circle the moon, unoccupied, until the crew's return from the lunar surface, via the lander, for the ride back to Earth. During Apollo, one man remained behind in the moon-orbiting command module.

"Going well beyond Apollo, we seek the ability to land and conduct exploration activities anywhere on the moon, including on the far side or in the polar regions," Griffin said.

Astronauts last visited the moon in December 1972.

Mars as a human destination takes a back seat in NASA's plans, which is sure to irritate on-to-Mars advocates. Space officials insist a lunar program involves crucial groundwork for Mars expeditions. But as Logsdon noted, "If you don't have money to go to the moon before 2018, you sure as hell don't have money to go to Mars."

One lingering question, and concern, among lawmakers is how much all this will cost. The rebuilding of the Gulf Coast in the wake of Hurricane Katrina (search) is sure to intrude on all aspects of government spending.

"The fact that it comes at a particularly inopportune moment is unfortunate, but either we are serious about long-term commitments like this or not. Nobody is asking for more money," Logsdon said. "Apollo was done as a warlike mobilization of national resources and there's no reason to do that now."