If the shuttle Discovery launches on time July 13 it will mark the 90th day of Mike Griffin's tenure as NASA administrator, a fitting culmination for three months of change so profound and so rapid that people in government and industry are still struggling to keep up.

Nearly three months into his tenure the 55-year-old aerospace veteran has wasted no time making his mark on the U.S. space agency, as he and his team addressed a wide range of vexing problems. He set a firm 2010 deadline for retiring the space shuttle and accelerated the effort to field its replacement. He also set in motion an accelerated effort to come up with an overall plan for turning U.S. President George W. Bush's call to return to the Moon by 2020 into a reality.

Many of the hardest decisions lie ahead, but as the 90-day point approaches, NASA's lunar exploration plans--including the type of Crew Exploration Vehicle, the launchers and other hardware it will need to get back to the Moon and stay--are coming into focus. Likewise, Griffin has made clear where the U.S. space agency is headed on a number of issues that have dogged NASA for the past year or more, from repair of the Hubble Space Telescope to how the international space station fits into NASA's space exploration plans.

The return to flight of the Space Shuttle Discovery--more than two and a half years after the shuttle Columbia was destroyed during re-entry--is considered by the White House and Griffin to be the critical first step on a journey that is intended to lead the U.S. human spaceflight program out of the low Earth-orbit rut it has been stuck in since the Apollo program ended 30 years ago this month.

Griffin's overriding goal, according to those who know him well, is to ensure that the United States is well on its way back to the Moon--this time to stay--by the end of his tenure at NASA.

Griffin has said he does not intend to stay on as NASA administrator past the end of Bush's second four-year term. So when Griffin was sworn in April 14, both his mission and timetable were clear: 45 months to get NASA moving in the right direction and with enough momentum that there will be no turning back.

"Mike Griffin knows that of all the resources available to public-sector leaders, the one you can never recover is time," said Jim Muncy, a former congressional aide and president of PoliSpace, an Alexandria, Va.-consulting company. "If you ask any of his key people, they know how many months they have left to transform that agency."

Courtney Stadd, a private consultant who served as a paid advisor to Griffin until late June, said Griffin is part of a generation of aerospace leaders who came of age as the Apollo program was winding down and are determined not to blow this chance to stake a permanent claim in space.

"If he is not successful in getting momentum behind the next-generation transportation system, if he is not successful getting bipartisan support behind a credible architecture that can take us to Moon and Mars, then it won't survive multiple presidential administrations or changes in the leadership of Congress," Stadd said. "We all went into this realizing this is our one last shot in the arena."

Griffin is earning plaudits for his full-speed-ahead approach. Rep. Ralph Hall, a Texas Republican with a strong interest in the livelihoods of Houston's Johnson Space Center employees, told Griffin during a NASA hearing late last month: "I'm glad to see you with your hand on the throttle."

But some admit to feeling a bit motion sick from the rapid pace of change Griffin.

"For those of us who like him, the concern would be that he has bitten off too much too soon," said a Washington-based aerospace industry official. "Our industry is very slow to change. It takes them a while to get used to things and this has hit them like a shock wave. There are industry people reeling from all the change."

A Whirlwind Start

Griffin was sworn in as NASA Administrator just two days after a remarkably swift Senate confirmation notable for the bipartisan display of support for his nomination. But even before Griffin took the oath of office, he already had set in motion a number of big changes, telling the senators presiding over his confirmation hearing that the space shuttle would be retired before the end of 2010 regardless of whether the international space station is fully assembled by then, that he intended to speed up the development of the Crew Exploration Vehicle to avoid a lengthy interruption in the ability of the United States to launch astronauts into orbit, and that he would revisit his predecessor's decision to cancel a long-planned shuttle mission to service the Hubble Space Telescope.

The following week, during his first press conference as NASA administrator, Griffin said he was unhappy with the slow pace of a strategic planning activity, started by his predecessor Sean O'Keefe, to map out a viable path to the Moon and Mars. He said he intended to replace the 13 so-called Strategic Roadmap Committees with a small, handpicked team to speed up the planning process, and eight days later, he did just that, putting fellow Orbital Sciences Corp. alumnus Doug Stanley in charge of a 60-day effort to sort through the dozens of exploration architectures that had been proposed over the years and pick one. Stanley and other NASA officials began briefing congressional staffers and aerospace industry representatives the week of July 4 on the results of the so-called Exploration Systems Architecture Study, which calls for building an Apollo-like astronaut capsule and conducting up to six lunar sorties a year using rocket hardware derived from the space shuttle.

Longtime Griffin associates said they were not surprised by his rapid start.

"Those of us who talked to Mike before he was formally nominated know that he was very impatient with the pace of exploration planning," said John Logsdon, director of the Space Policy Institute at George Washington University here. "He had a good idea for several months before his nomination that he was in the running for the job, and so clearly was thinking about what he would do if that happened. So his quick start is not a surprise."

Stadd, who served in senior posts under NASA's two previous administrators, said Griffin is "probably the best prepared" of any administrator in the agency's nearly 50-year history for the challenges the job entails.

Griffin has earned six advanced degrees, including a master's of business administration and a doctorate in aerospace engineering, and has been a Pentagon technologist, corporate executive, a national lab director and even a NASA associate administrator.

"He has been a student of the agency for decades," Stadd said. "In some cases he has been incubating these positions for a long time."

Impatient but Politically Astute

Griffin readily admits he is not known for his patience.

"A former boss, whom I liked a lot, once said that 'Mike not only has no patience, you would have to add patience to Mike to get up to zero,'" Griffin told a Washington audience early in his tenure. "I think it was a true statement."

Federal employment rules require new agency heads to wait 120 days before involuntarily reassigning top deputies, who usually fall into a class of senior government employees who typically have traded job security for the opportunity to earn higher pay. Those same rules require agency heads to give employees 60-days notice when they will be reassigned to different jobs, like it or not.

On June 13--exactly 60 days into his tenure--Griffin began notifying dozens of NASA senior executives that they were being reassigned.

The heads of NASA's four primary mission directorates have since announced that they are leaving, have left already, or are considering taking another job within the agency come August.

Rep. Dana Rohrabacher (R-Calif.), a senior member of the House Science Committee and vocal space exploration advocate, recently likened Griffin to the fictional character Conan the Barbarian for moving so quickly in sacking senior managers.

Lori Garver, a Washington-based space consultant and former senior NASA official, said the personnel shake up is no surprise given what she called Griffin's desire "to make significant and irreversible progress on the vision."

"Getting your team together is one of the most important things you can do and he's wasted no time," she said.

If Griffin has shown an urgency to get moving on personnel, programmatic and policy decisions, one area where Griffin has not rushed is the space shuttle's return to flight. Griffin dove head first into NASA's preparations to fly the shuttle for the first time since the February 2003 Columbia accident, frequently winging down to Kennedy Space Center to participate in technical reviews.

In late April, Griffin announced that return to flight would be postponed at least six weeks to mid-July to allow more time for debris analysis and to install another heater on Discovery's external tank. (Debris shedding from that tank is blamed for causing the Columbia accident.)

Griffin also is credited with patiently sowing the seeds for long-term political support for the exploration vision, reaching out to lawmakers in both major political parties.

"He's listening to everybody," one Washington aerospace consultant said.

Stadd described Griffin as "a realist who understands that it is only through bipartisan buy-in that this program has any chance of surviving in future years."

"He will deal with and cooperate with any stakeholder whose interest is the long-term success of the civil space program," Stadd said.

Lawmakers in both major U.S. political parties appear to appreciate Griffin's characteristic candor, even if they do not always like what he has to say.

Rep. Tom Feeney, a Florida Republican whose congressional district includes Kennedy Space Center, expressed his confidence in Griffin during a recent House Science Committee hearing.

"You have reorganized both personnel and mission; you have made some very critical, decisive judgments that are going to be criticized by a lot of us," Feeney said. "But you've done so with the sort of confidence and level of expertise and background that give me confidence that we're doing what we need to be doing."

Logsdon, who has known every NASA administrator in the agency's 47-year-history, said if there is one thing that has surprised him about Griffin's tenure to date, it is how well various stakeholders around Washington have responded to Griffin's no-nonsense demeanor.

"I am surprised by the across-the-board extremely positive reaction--even from some who stand to get lower priority--to his qualifications. Almost everyone associated with the U.S. space effort knows Mike and respects him for his technical depth and integrity," Logsdon said.

Many challenges still await Griffin, and not all of his decisions will enjoy widespread support. In the months ahead, NASA faces tough choices on the space shuttle flight manifest, space station research, aeronautics funding and a $1 billion overrun on the James Webb Space Telescope that threatens to swamp other astronomy projects if not addressed.

"He will have to deal with the organized opposition of those segments of the aerospace community--[for example] space science not linked to exploration [and] aeronautics--who have powerful allies in Congress," Logsdon said. "And he will soon start making choices on launch vehicles, the [Crew Exploration Vehicle] contractor and other major programs. He cannot please everyone with those choices."