WASHINGTON — The $577 million shortfall dealt to NASA’s Exploration Systems Mission Directorate by the no-frills 2007 spending plan just enacted has ratcheted up the pressure on a robotic lunar lander project that has been in and out of the U.S. space agency’s budget cross hairs for more than a year.

NASA Administrator Mike Griffin, unveiling his agency’s latest budget request Feb. 5, announced that Moon-bound robotic missions beyond the Lunar Reconnaissance Orbiter (LRO) that is slated for launch in 2008 might have to be curtailed to pay for crew and cargo launch services to the international space station. NASA has budgeted $1.2 billion of the $2.1 billion it expects to have to spend on crew and cargo services through 2012. While Griffin has challenged his managers to make up the $900 million shortfall without canceling the robotics program, he said that might not be possible. That money covers the Soyuz, Progress, Commercial Orbital Transportation Services, Automated Transfer Vehicle and possible Crew Exploration Vehicle cargo missions.

“So, if we are simply not able to find the money elsewhere within the context of a fixed top-line [budget], I have made the point that the next most expendable thing we have available is lunar robotics, and that would be the only bill payer that I can find in the context of our present suite of programs,” Griffin said.

When President George W. Bush unveiled the Vision for Space Exploration in January 2004 he called for sending a series of robotic missions to the Moon starting in 2008 to help prepare the way for humans.

NASA responded by assigning its Greenbelt, Md.-based Goddard Space Flight Center responsibility for LRO, a $700 million mission to map the Moon in unprecedented detail. NASA has since added to the mission an $80 million lunar impactor proposed by its Mountain View, Calif.-based Ames Research Center to take advantage of the extra room aboard the Atlas 5 rocket that will be used for the mission.

NASA also had been planning for the better part of two years to follow LRO with a 2011 robotic lander mission le d by its Huntsville, Ala.-based Marshall Space Flight Center.

When NASA announced in September 2005 that the lander would be built for Marshall by the Laurel, Md.-based Johns Hopkins Applied Physics Laboratory (APL), the project was billed as a $500 million to $700 million undertaking. Though internal estimates at one point doubled, Griffin last summer set that target at $400 million to $500 million.

Now, however, the lander mission stands to be postponed until at least 2013 and possibly canceled altogether. The U.S. space agency, meanwhile, is looking at a number of alternatives to the Marshall-led project, including: a small, low-cost mission proposed by Ames and Goddard; a less science-driven lander that would have more in common with the eventual human lander; and, as Griffin mentioned during the budget briefing, collaboration with other nations.

NASA officials were not ready the week of Feb. 12 to talk about what the future holds in store for the Marshall-led lander project.

Doug Cooke, NASA’s deputy associate administrator for exploration, said the agency was “still in a hold mode” until it had a chance to re-examine the implications of the current budget situation for 2007 and beyond. By mid-March, NASA is expected to send an updated operating plan to Congress detailing the choices it has made.

Meanwhile, Applied Physics Laboratory officials are waiting to see what becomes of their project, one of only two civil space missions the lab has in the pipeline.

Walt Faulconer, APL’s civil space business area executive, said during a Feb. 12 interview that the laboratory has been told by NASA it should expect to remain in a pre-development phase on the lander for at least another year or two.

“We’ve been told the best case is wait a year before really getting started on it. The worst case is it’s canceled all together,” Faulconer said.

Faulconer said APL has been in what he called an “extended pre-phase A” since February 2006 when NASA decided it wanted to complete a more detailed lunar exploration plan before making a bigger commitment to the robotic lander project.

When NASA finally presented the results of its so-called lunar architecture at the Second Space Exploration Conference in Houston in early December, a series of four landers were still in the mix. But Tony Lavoie, the NASA official who led the Lunar Architecture Team, warned at the time that the lander plans could be undone by budget constraints.

Two weeks later, the incoming Democratic Congress announced it planned to hold most government agencies, including NASA, to their 2006 spending levels in 2007 rather than waste time trying to complete a pile of unfinished spending bills.

Up until Congress announced its plans to pass a bare bones continuing resolution, Brian Morse, APL’s lunar lander project manager, said he had been feeling more confident the lander would soon get the green light to move forward into development.

“I will say that in early December I felt pretty good about it,” Morse said. “Until the realities of the [continuing resolution] and the effect that it had on ’07 hit, that’s when I started getting nervous again.”

Morse said he has only two people on the project full time, including himself. About 20 APL engineers in total have been brought in and out of the project as their expertise was needed, he said.

He said he thinks APL and its Marshall teammates have made good use of its extended pre-development funding to date, producing detailed examinations of the various options for the lander and what it would take to get the mission done. Staying productive, however, could be more of a challenge.

“If we are in a really extended study phase from now forward we are going to have to do some planning to make sure that is productive,” Morse said.