NASA Administrator Mike Griffin returned to the House Science Committee Nov. 3 to answer a litany of questions lawmakers first asked back in June about the U.S. space agency’s new direction. At the hearing, Griffin also publicly acknowledged what many in the space community have known for months -‑ that the space shuttle program needs about $5 billion more than previously budgeted for the five years remaining until its planned retirement.

During Griffin’s last appearance before the committee, he assured lawmakers that he would be ready by September to discuss the agency’s plan for returning to the Moon, including the new spacecraft and launch vehicles it will need to get the job done. He also said he would be ready to describe in some greater detail NASA’s plan for completing the international space station and retiring the space shuttle orbiters.

Since that June appearance, NASA has rolled out its space exploration architecture, declared that it wants to build a six-person capsule capable of trips to the space station and the Moon, and decided to use space shuttle components as the foundation for its proposed Crew Launch Vehicle and Heavy Lift Vehicle. NASA also has said it intends to fly 18 more shuttle missions to the space station, a number sufficient to honor its major commitments to its international partners by launching Europe’s Columbus science laboratory and the Japanese Experiment Module.

Griffin received an abundance of goodwill and well wishes from lawmakers during his June appearance — his first as NASA administrator.

“You have started very well. You’ve been bold, you’ve been making decisions and have set up a process for making decisions that cannot be made now,” Rep. Dana Rohrabacher, the California Republican in line to become House Science Committee chairman come 2007, said back in June.

Much of that goodwill appears to remain. Although lawmakers were at times pointed in their questions about the feasibility of NASA’s plans for completing the station and expressed skepticism about the affordability of the exploration plan the agency has since laid out, the committee’s top Republicans and Democrats told Griffin he still has their confidence.

“After about six months on the job I want to assure you, you are still our hero,” House Science Committee Chairman Sherwood Boehlert (R-N.Y.) said at the outset of the Nov. 3 hearing. “You have retained your candor and you have been remarkably successful at fulfilling the commitments you have made.”

However, Boehlert pulled no punches in his assessment of NASA’s budget situation.

“While NASA may have relatively smooth sailing right now we ignore the clouds on the horizon at our own peril,” Boehlert said. “There is simply not enough money in NASA’s budget to undertake all the tasks it is undertaking and maintain the current schedule.”

Boehlert said he did not see how NASA could fulfill its commitment to complete the international space station, keep the Crew Exploration Vehicle (CEV) development on track for a 2012 debut, and maintain a robust science and aeronautics program with the relatively flat NASA budgets forecast for the years ahead.

“Before NASA promises it can accelerate construction of the CEV, complete construction of the [international space station] and have worthwhile science and aeronautics programs, it ought to be able to demonstrate where the money will come from and right now it cannot,” Boehlert said.

Rep. Bart Gordon (D-Tenn.), the committee’s ranking Democrat, said he fully concurred both with Boehlert’s praise of Griffin and the chairman’s depiction of NASA’s budgetary challenges in the years ahead.

Griffin sought to assure lawmakers that NASA has budgeted adequately for the CEV. NASA is seeking $1.9 billion for the CEV for 2006, $785 million more than it had been seeking when it sent Congress its budget request in February.

Griffin also testified that he intends to spend upwards of a “half a billion dollars” in the coming years to “subsidize” development of commercial systems capable of delivering cargo and potentially people to the space station cheaper than NASA could using the CEV.

When Griffin said that keeping CEV development on track would be a top priority, Gordon said the commitment should serve as a warning to other NASA programs that their budgets will suffer if CEV needs more money than expected.

NASA’s biggest budget problem by far, at least in the near term, is the space shuttle program.

Over the next five years, according to recent internal estimates, NASA needs as much as $5.6 billion more than currently budgeted to accomplish the 19 shuttle flights it intends to make before retiring the orbiter fleet in 2010. Most of that shortfall is the result of a five-year budget plan that forecast a $4.8 billion decline in shuttle spending between 2006 and 2010.

Griffin, testifying that NASA is working hard to find savings within the shuttle program, would be no more specific about the space shuttle budget shortfall than to say it is between $3 billion and $5 billion.

The shuttle is not NASA’s only budget problem.

Hurricane Katrina damaged NASA’s Stennis Space Center in Mississippi and the Michoud Assembly Facility outside New Orleans, setting back preparations for the next space shuttle mission.

NASA’s cost estimate for recovering from Hurricane Katrina is $760 million. The White House supplemental request includes only $325 million for NASA and leaves it unclear whether a second hurricane relief supplemental, due in May, will request the balance of what NASA needs.

The agency also faces $1 billion in cost growth on the James Webb Space Telescope. As a result, NASA has decided to slip the launch date two years to 2013 rather than scale back the telescope’s scientific capabilities.

NASA already has made some cuts to address these budget problems.

Spending on space station research is being cut in half heading into 2006.

The Project Prometheus nuclear power and propulsion program, once a major initiative, has been reduced to a low-level research effort. Its 2005 budget of $430 million shrinks to $100 million in 2006, all but $10 million of which will be used to pay closeout costs on canceled contracts.

Griffin caught some flak for the life sciences cuts, particularly from committee Reps. Mark Udall (D-Colo.) and Michael Honda (D-Calif.). Griffin said the life sciences cuts are necessary in light of NASA’s new direction.

On the topic of sending a shuttle to service the Hubble Space Telescope — a program important to many lawmakers including Udall and his Boulder-area constituents — Griffin had greater assurances to offer.

Griffin has said consistently since his confirmation in April that a final decision on servicing Hubble will be made after NASA’s second post-Columbia shuttle mission. But he left lawmakers with little doubt about the agency’s intentions.

“Frankly, it is my highest priority for the shuttle program,” Griffin said.

Brian Berger is editor in chief of SpaceNews.com and the SpaceNews magazine. He joined SpaceNews.com in 1998, spending his first decade with the publication covering NASA. His reporting on the 2003 Space Shuttle Columbia accident was...