NASA Administrator Sean O'Keefe is Dick Cheney's man, used in the past by the vice president to tackle difficult problems. But handling the fallout from yesterday's space shuttle disaster could be the toughest job the NASA chief ever faces.

"When I saw him today, I said, 'You're going to earn your spurs now, because this is going to be a time when the agency is going to have to have a really good leader,' " Sen. Bill Nelson, the Florida Democrat who flew on the space shuttle in 1986, said yesterday.

Like Cheney, O'Keefe has a reputation of being a hard-nosed manager. "He made some really tough decisions on the budget" when he was the Pentagon's top financial officer under then-Defense Secretary Cheney, recalled retired Rear. Adm. David Oliver.

When the Navy was in turmoil over the 1991 Tailhook sexual harassment scandal, Cheney moved O'Keefe to be the secretary of the Navy, with a mandate to clean up that mess. Again, said Oliver, "he made tough decisions, including firing some people and got the Navy out of it."

Then last year, he inherited a space agency wracked by cost overruns and management disarray and restored order. But unlike Cheney, who is seen as a rather distant, even cold boss, O'Keefe is known for making human connections, regularly attending space launches to rub elbows with NASA brass and even for being a partier.

One person who worked for O'Keefe when he was Navy secretary recalls flying to O'Keefe's hometown, New Orleans, and promptly going to an old Irish bar with him. "It was like 'Cheers' -- everyone knew him," this former Navy official recalled. "Sean and his brother were singing Irish tunes, not well, but loudly." They closed the place down, and a few hours later, O'Keefe delivered a breakfast speech, "none the worse for wear."

A 1977 graduate of New Orleans' Loyola University, O'Keefe began his professional Washington life as many do, working on Capitol Hill. He spent most of the 1980s on the staff of the Senate Appropriations Committee. It was Alaska Republican Sen. Ted Stevens, a longtime member of that panel, who proposed that O'Keefe become the Pentagon's comptroller, recalled Dave Gribbin, who was Cheney's assistant secretary for congressional affairs.

"I don't think Cheney knew Sean very well when Sean came into the Defense Department" as comptroller in 1989, recalled Gribbin. "But once Cheney met him, he made a real impression."

O'Keefe also left in style. On his last day at the Pentagon, he hired a bagpiper to play "Anchors Aweigh" and other tunes, and to stride before him as he left the building, recalled the former Navy official. O'Keefe made a point of taking a detour from his normal route and marching, along with a growing entourage, through the office of the secretary of the Air Force, always a fierce competitor for Pentagon funds.

O'Keefe spent the Clinton years running national security studies at Syracuse University's Maxwell School of Citizenship and Public Affairs. That stint spoke to O'Keefe's other side, as a student of how government works. "He not only knows the numbers, but also understands the politics and the process," said Gribbin. "You don't get a lot of those people."

That dual talent should serve him well as NASA deals with the causes of the crash and seeks to answer questions about the space program's future, Gribbin said. "He really understands how governments work, but he also will remember that in the end, this is about people," he said.

When the second Bush administration began, O'Keefe returned to Washington as deputy director of the Office of Management and Budget. In December 2001, he became administrator of NASA, succeeding Daniel S. Goldin. Goldin had run the agency for nearly a decade. During his tenure, he increased the number and reduced the size of unmanned spacecraft exploring the solar system, presided over the repair of the Hubble Space Telescope and launched what became the international space station project. But by the time he left, the agency was in turmoil, and the space station project was running $4.8 billion over budget.

O'Keefe brought to the space agency a twin mission: First, to get its budget under control and, especially, to rein in costs on the international space station. "Let's get the house in order," he said at his confirmation hearing. Second, some in the Bush administration thought NASA had become too disconnected from the Pentagon -- at the time when the U.S. military was becoming dependent on space for communications, navigation and surveillance. Most of today's precision-guided bombs, for example, depend on signals from global positioning satellites to hit their targets.

When the administration thought about space, it was usually in military terms: Running for president in 2000, George W. Bush talked little about space programs but much about how he wanted to give the nation the ability to knock down enemy missiles in space.

O'Keefe also reassured NASA personnel that he endorsed the agency's zero-defects ethic. In a memo issued last April that is posted on the NASA headquarters Web site, he stated, "The Agency's safety legacy is paramount. Keep up the good work, but always remember that mission success starts and ends with safety for everything we do."

While "safety first" was the watchword of NASA's space launches, critics complained that Bush administration belt-tightening and shifting priorities were denying Columbia and the three other aging shuttles necessary upgrades and improvements. At issue was whether it made sense to sink billions more into upgrading and improving the space shuttles when administration planners hoped to phase out the fleet within the next decade to make way for a new generation of spacecraft, or to possibly contract out future missions to private companies.

Government spending on NASA human flight has remained relatively flat for years -- a little more than $6 billion annually -- and some lawmakers complained that O'Keefe and the administration were shortchanging shuttle maintenance and upkeep.

O'Keefe testified last February that NASA had "canceled or deferred" a number of shuttle upgrades, while he tightened the reins on spending for the space station. Nelson and other members of the Senate Commerce, Science and Transportation Committee complained that the administration was shortchanging the shuttle program: "We're starving NASA's shuttle budget -- and thus greatly increasing the chances of catastrophic loss."

Last November, O'Keefe and the administration acknowledged that a problem existed with the funding for shuttle maintenance and added money to the budget. Nelson said yesterday that there is no indication that the disintegration of Columbia and its crew was linked to maintenance problems. "But the point is, if you don't tend to safety, sooner or later it's going to catch up to you, because space flight is risky business," he said.

Congressional aides praised O'Keefe for restoring morale and sound management practices to NASA and predicted that Congress would work closely with him throughout the investigation of the disaster and deliberations over the agency's budgetary needs.

"He's really tried to say that we're not going to have any credibility until we put this financial mess behind us, which is something folks on the Hill agree with," said a Senate Democratic aide. "He's somebody who is really sincere about this."

NASA Administrator Sean O'Keefe, a former secretary of the Navy, has a reputation for making tough decisions but doing so with a humane touch.