WASHINGTON — Challenging a $670 million cut by the U.S. House of Representatives to the president’s $18.7 billion NASA budget request, members of the U.S. Senate Appropriations Committee last week fully funded the 2010 proposal, part of a larger $64.9 billion spending package for the Commerce and Justice departments and several independent agencies. NASA observers say the space agency’s shuttle replacement program could be delayed by as much as two years if the House version of the bill, approved June 18, is signed into law.

The House bill recommends trimming more than $500 million from the president’s proposed $3.5 billion budget request for NASA’s Constellation program, an effort to replace a space shuttle fleet expected to conduct its final missions next year. Constellation’s Orion crew capsule and Ares 1 rocket are slated for initial operational capability by March 2015, leaving a five-year gap between retirement of the legacy shuttle program and NASA’s follow-on capability.

“If you look at the House Appropriations reductions, it represents about a 20 percent hit to the contractor work force, which means the House has just increased the gap by maybe another two years with that stance,” said Scott Pace, director of the Space Policy Institute at George Washington University and former head of NASA’s Office of Program Analysis and Evaluation under the previous administration. “With President [Barack] Obama’s budget, NASA still had a shot at Ares 1 happening by March of 2015.”

The House bill proposed $1.2 billion for Orion, about $160 million below the administration’s request. It would also trim nearly $400 million from NASA’s $1.41 billion request for Ares 1 and possibly result in the loss of about 4,000 new and existing jobs, or more than 20 percent of the planned Constellation work force, according to sources familiar with NASA’s budget.

“What’s galling is that the House mark is creating a boom-bust problem with Recovery Act funds followed by cuts the next year,” said one former NASA official, referring to $1 billion in 2009 stimulus funds the space agency garnered earlier this year, before the House passed its version of the 2010 NASA appropriations June 18. “NASA can’t execute multi-year programs like this without significant impacts.”

U.S. Rep. Alan Mollohan (D-W.Va.), who chairs the House Appropriations commerce, justice, science subcommittee, recommended a funding reduction of more than $500 million for Constellation until the results of a blue-ribbon panel charged with assessing NASA’s manned spaceflight program are presented to the White House in August. Mollohan has described the reduction as a “timeout” or “pause” until the panel presents a range of options to the administration on the path forward. Mollohan said he fully expects the Obama administration to submit a budget amendment for space exploration programs in September, allowing time for lawmakers to adjust 2010 funding.

U.S. Sen. Barbara Mikulski (D-Md.) said she, too, looks forward to the panel’s findings. But during a June 24 Senate Appropriations commerce, justice, science subcommittee markup of the NASA request, Mikulski rebuffed the House proposal.

“We do not agree with the House strategy that cut $500 million from NASA exploration,” said Mikulski, who chairs the subcommittee. Mikulski thanked the president for appointing the blue-ribbon panel. “We look forward to that report as we move forward with our appropriations.”

The Senate version of the bill fully funds the president’s $3.5 billion request for Constellation and quadruples NASA’s $25 million request for early work on Ares 5, the Moon-bound heavy-lift rocket being designed at NASA’s Marshall Space Flight Center in Huntsville, Ala., the home state of subcommittee ranking member Sen. Richard Shelby (R-Ala.). The Senate Appropriations Committee approved the bill June 25.

The Senate version of the bill does not include language in the House version that would require NASA to commit money for most of its research and development contracts within a single year. Critics of the House provision contend the restriction could negatively impact the space shuttle program. Given recent White House assurances that NASA will fly all eight remaining shuttle missions even if that means going beyond the September 2010 retirement target, NASA may need to roll over 2010 funds into 2011 to complete the last of the shuttle flights.

“Large [research and development] agencies like NASA need flexibility with two year funding,” the former NASA official said.

In a June 16 statement of administration policy, the White House Office of Management and Budget said the House restriction “would increase the cost and complexity of budget execution and would diminish flexibility without improving management.”

The White House budget office also criticized the proposed $670 million reduction included in the House bill and expressed concern about the elimination of $21 million from the request for NASA’s Innovative Partnership Program, which funds the Centennial Challenges prize program, among other public-private partnerships aimed at spurring new technological development.