There's building speculation in Washington that President Bush will soon announce a long-term space exploration program that could send Americans back to the moon to build a base as a first step to Mars.

A lunar base, some experts say, could have a price tag of $50 billion to $150 billion depending on how many people and what equipment are used. "That's a good guess, and it comes off studies NASA has done over the past few years," American University space expert Howard McCurdy said in an interview last month.

But Dennis Wingo of Huntsville, part owner of two companies developing space hardware, called that estimate "wildly inflated.'' He said it would cost only about $10 billion over five years to build a moon base.

"You don't have to rebuild the Saturn V to do this,'' Wingo said. "We've got a perfectly good rocket built by Boeing out in Decatur that can do this work.'' Boeing builds its heavy-lift Delta IV rocket at its plant in Decatur.

Others peg the costs even lower, about $6 billion to set up, with a $1.4 billion a year operations cost, according to Huntsville space consultant Gordon Woodcock.

The launch vehicle and launch operations are already in place, said Wingo, who has spent more than 20 years in the space and defense business.

Several Delta IV flights, along with space shuttle servicing missions, could be used to build an advanced rocket and assemble a lunar base in orbit around the Earth.

"That's what (Wernher) von Braun wanted to do with the Saturn I or the Saturn IB they designed (at Marshall Space Flight Center)," Wingo said. "Earth orbit assembly made sense 40 years ago, and it makes sense today.''

Built in Earth orbit

The concept of Earth orbit construction dates to the late 1950s, when von Braun and his rocket team planned to launch a man to the moon. The idea was to launch several rockets and build a large lunar spaceship in orbit around the Earth.

Rockets were not powerful enough, and still aren't, to take all the needed materials for a lengthy lunar mission on one launch. To von Braun, the logical way was to assemble what was needed around the Earth. But the plan was scrapped because many felt it was too dangerous and too costly.

Eventually, the Saturn V rocket was approved, and the Earth orbit rendezvous plan was changed to a lunar orbit rendezvous where the lunar lander and Apollo Command Module link up.

Wingo noted that space shuttle astronauts have built or serviced things while in orbit, including the Hubble Space Telescope and the International Space Station.

Also, more advanced technologies could be used to supply the lunar base. Wingo said a space tug, which would be an unmanned supply ship, could be used to take supplies to the moon before a lunar landing took place. The tugs could be used as a sort of "orbital skylift" to the moon. By placing them on certain trajectories, the tugs could be recaptured, serviced and fitted with more supplies, creating a supply line to the moon.

Woodcock, the space consultant, envisions an Earth-Moon midpoint refueling station that could be placed where the Earth's and lunar gravity cancel each other out. Dubbed a "gateway" base, the stopover would allow crews to refuel, refurbish and tend to an Apollo 13-like emergency during a lunar voyage. Woodcock said the habitable facility reduces the mission risk by providing a refuge near the moon. It could also be used for rescue operations to the lunar surface, he said.

Look who's talking

The Feb. 1 Columbia accident spurred the Bush White House to take a hard look at America's overall space policy, NASA Administrator Sean O'Keefe said during a meeting with his advisory panel in Washington last week.

"There has been debate on this subject and that's what (Congress) and the public wanted," O'Keefe said. O'Keefe wouldn't release any details of the Bush space plan, but he said repeatedly that 2004 "would be a seminal year for NASA" and "to expect very significant changes."

But NASA is only part of an overall space policy, O'Keefe said. The discussions at the White House, which have involved the president's staff and Vice President Dick Cheney, include the Department of Defense, Department of Commerce and the Department of Transportation - all which have independent space interests.

The Pentagon has about $20 billion of its $400 billion budget allocated to space operations and research. NASA's budget is $15 billion. Commerce and Transportation set policy for space business.

John Glenn, former senator and the first American to orbit the Earth, wondered whether the Bush space policy might diminish NASA's role in America's space program. He told O'Keefe last week that a wide-ranging policy could have bad implications for NASA and might slow plans to complete the space station and build an Orbital Space Plane or crew rescue vehicle.

"I thought you were in charge of such decisions," Glenn told O'Keefe at a NASA Advisory Council meeting.

O'Keefe said the space policy would bolster NASA's standing, not diminish it.

Why not?

The biggest question Bush must grapple with is not whether but why America should go back to the moon. O'Keefe said the "why question" has to be answered before any plans are made.

Glenn said a trip to the moon for political or "sightseeing" reasons had been done already and shouldn't be attempted again unless part of a larger plan.

"Should we go to the moon just to build an expensive base and do nothing? No, there's no payoff for the investment in that," Glenn said in an interview last week. "Should we use the moon as a stepping stone, or a place to learn how to go to Mars? Yes, and if that's the plan I'm all for it."

Glenn said most science research could be done on the space station and that it should be completed. "Or we could replace a shuttle, which I'm in support of. We can't continue to support the station and other projects with three shuttles that are getting older by the minute," he said.

Safety considerations could scuttle use of a shuttle. NASA is already backing off plans to service the Hubble Space Telescope in 2007 because post-Columbia shuttle missions will have to be in an orbit where a docking with the space station is possible.

"We haven't given up on Hubble, but safety is the key driver here," NASA's Deputy Administrator Fred Gregory said last week. "Now, there is a limit on shuttle flights. ... We might not be able to get to certain orbits."

NASA would likely have to make extensive improvements to the shuttle if it were to be used for other construction plans. The White House vision should encompass the next 20-30 years, and other vehicles might be in the offing, though.

In the end, a plan to return to the moon might be driven by money and not science. Studies of the moon conducted on samples brought back by the Apollo landings, moon probes and recently Chandra X-Ray telescope images show the moon has valuable elements locked away in its craters and valleys.

Metals may be in meteor impact areas on the moon, Wingo said, and they could be used to develop hydrogen fuel cells for use back on the energy-hungry Earth.

Wingo compares a lunar scientific mission to the Lewis and Clark expedition of America's uncharted territories in the early 19th century. "They opened up the frontier through exploration, but the government didn't build the (subsequent) railroads or the mining interests. Private industry did that," he said.