Advocates of space exploration want an American astronaut to take one more small step on the Moon, and the first steps on Mars. But in a spending bill approved last week, House lawmakers told them to take a hike.

To help meet caps negotiated with the White House, the House slashed $577 million from the budget request for a program to replace the NASA Space Shuttle. If those cuts are upheld by the Senate, the space agency could be forced to push back the planned 2014 launch of the new craft, called the Orion. Flights to the moon and Mars would be rolled back, too.

The move has sent aerospace industry lobbyists and citizen activists scrambling to make up ground in the Senate. But with Senators poised to adopt the fiscal 2007 spending plan largely untouched, aides and lobbyists pushing for more money aren’t holding their breath.

The bill “isn’t going to change in the Senate,” one Democratic aide said. “Nobody is happy, but this is what we inherited from the Republican Congress.”

Added J.P. Stevens, vice president of space systems for the Aerospace Industries Association of America: “It’s not looking good.”

The situation reflects how dramatically the fortunes of a cause can shift when it loses a powerful Congressional champion. For years, the National Aeronautics and Space Administration, and space exploration in particular, rolled over Congressional budget hawks with the iron-clad support of then-House Majority Leader Tom DeLay (R-Texas), a self-described “space nut.”

During the controversial redistricting plan that he engineered, DeLay maneuvered the Johnson Space Center into his own district and quickly went to work delivering it federal dollars.

He saved the very program targeted by the latest cuts — a White House initiative for manned flights to the moon and Mars dubbed the “Vision for Space Exploration” — in the closing days of 2004 by threatening to scuttle an omnibus spending bill unless it was fully funded.

And he oversaw a restructuring of the House Appropriations Committee in 2005, which critics charged was simply an elaborate plan to goose the NASA budget. Later that spring, he even coached a grass-roots group called Citizens for Space Exploration on how to lobby their representatives for more agency money. “When you get in there with the members, give them all the facts, but don’t hide your passion,” he told the group, according to an account in the Houston Chronicle.

DeLay’s replacement, Rep. Nick Lampson (D-Texas), voted to uphold the cuts by supporting the 2007 spending package last week. Lampson, in a statement, called the cuts a result of Republican gamesmanship with the federal budget at the end of the 109th Congress. The Johnson Space Center “fuels valuable research and the economy of Southeast Texas, and I will work tirelessly with colleagues on both sides of the aisle to increase NASA funding and ensure that JSC remains the flagship for human space exploration,” he said. “I am proud that the entire Houston delegation has pledged to work together to ensure that future missions are not imperiled by Congressional politics.”

Instead of the $16.8 billion the president requested for NASA, the House bill delivers $16.2 billion, about the same as its 2006 allotment. And it kills a $1 billion supplemental package some Senators had been pushing for.

Space advocates said the move will further extend the period between the 2010 retirement of the space shuttle and the Orion’s planned 2014 launch when Americans will be reliant on Russian crafts to reach the International Space Station. And, some contend, the delay could spell big trouble for the future of the American space program.

“This will have devastating and permanent consequences,” said Rep. Tom Feeney (R-Fla.), whose district is home to the Kennedy Space Center. “We learned when the first shuttle disaster occurred that if you’re out of the human space flight business for more than a few years, you lose a whole generation of scientists who know how to do this. One year may cost you 10 or 20. So in the Senate, it’s now or never.”

Aerospace industry lobbyists are forging ahead with a last-ditch effort to convince Senators this week that the cuts should be restored. The two companies with the most at stake: Lockheed Martin, which has already secured a $3.9 billion contract to produce the Orion, and Boeing, which is vying to develop the Ares I, the rocket meant to carry the new craft into space.

“This could jeopardize the timely development of both Orion and Ares,” said Lockheed spokeswoman Joan Underwood. Boeing and NASA declined to comment.

The project is getting support from Sens. Bill Nelson (D-Fla.) and Kay Bailey Hutchison (R-Texas), whose states each claim major space centers. The pair wrote to the Appropriations leaders last week asking them to meet Bush’s request of $16.8 billion for NASA.

Backers of the program will get a better idea of what they are up against today, when President Bush’s 2008 budget proposal is delivered to Congress. Depending on what the White House calls for, a Nelson aide said the Senator may push for a new supplemental spending measure.

A spokeswoman for Sen. Barbara Mikulski (D-Md.), another advocate for NASA funding, said she has been “fighting for increased funding for NASA’s bottom line for more than a year.”

“Unfortunately, the terms of the CR did not allow for an increase,” she said. “Within these tight constraints, however, Sen. Mikulski was still able to increase Exploration by $460 million, which should be considered a small victory given the situation the 110th Congress inherited.”

Besides Lockheed and Boeing, dozens of smaller contractors with a piece of the space program also stand to get pinched. They are organized under the banner of the Coalition for Space Exploration, which is heading up a lobbying campaign for a bigger share of federal money.

They are supplementing their inside-the-Beltway push with a national public relations effort to raise support for the space program. The coalition has launched a Web site, SpaceAdvocate.com, that allows registrants to e-mail their Representatives. The group also is deploying members of its Board of Advisers — which includes former astronaut Buzz Aldrin, film director James Cameron and CNN correspondent Miles O’Brien — to spread the gospel.

Meanwhile, Citizens for Space Exploration — a group affiliated with that coalition that is made up of small business owners, elected officials, and others from space industry hubs across the South — will return to town this spring for their annual fly-in less certain of their clout.

“We’ve lost a strong leader,” said group member David Braun. “There are certain advantages to having the Majority Leader with a space center in his district.”