U.S. President George W. Bush could not have made a better choice for NASA’s next administrator. Michael D. Griffin’s bulletproof credentials as an engineer, program manager and senior-level executive — not to mention his well-known passion for space exploration — make him the ideal choice to lead NASA as it prepares to extend humanity’s reach beyond the stubborn grip of low Earth orbit.

Dr. Griffin also brings considerable political skills to the job. And while these tend to be overshadowed by the rest of his resume, they may turn out to be his most valuable asset, because the tenacity of low Earth orbit’s grip has as much to do with politics as physics. Dr. Griffin’s reputation for candor, and for being willing to take on entrenched interests, has won him admirers in the space community, but he knows that these are not always the foremost qualities that one needs to tiptoe through the political minefield he is about to enter.

Indeed, much of what Dr. Griffin must do to jump start the president’s Moon-Mars initiative involves realigning and redirecting NASA’s resources and infrastructure. These actions are going to cause heartburn, and if they are not taken with the utmost care, finesse and discretion, the goodwill and support that Dr. Griffin enjoys today will quickly evaporate.

The internal and congressional opposition already engendered by NASA’s initial realignment plans provide just a hint of the challenge Dr. Griffin likely will face. He will have to tread carefully, because he will not succeed if he loses the confidence and trust of NASA’s workforce or Congress.

The experience of former NASA Administrator Daniel Goldin stands out as a stark warning in this regard. Unlike Dr. Griffin, Mr. Goldin was a relatively unknown quantity when he was selected to serve as NASA administrator, but he quickly established himself as an aggressive hard charger who was intent on “breaking a few rice-bowls” to get the troubled space station program on track and streamline the agency.

But Mr. Goldin’s blunt-force approach succeeded only in alienating his employees, industry and Congress. Part of his problem was that unrealistic goals were foisted upon him by the White House, but instead of pushing back or demanding more resources he resorted to making promises — especially on the space station program — that neither he nor anyone else could possibly keep.

As a result, Mr. Goldin’s relations with NASA’s workforce and with Capitol Hill soured beyond repair, undermining his ability to lead. An incident in 1993 in which members of the House Science Committee required Mr. Goldin and other senior NASA officials to stand up and swear to tell the truth illustrates the mistrust that settled in not long after he became administrator and endured throughout his tenure.

In such a poisonous atmosphere it is nearly impossible to institute modest reforms, let alone the realignment that will be necessary to get President Bush’s Moon-Mars initiative off the ground.

But Dr. Griffin didn’t get where he is today by being ham-handed, and judging from the rave reviews from lawmakers that greeted the news of his nomination, he will start out with some political capital to work with.

Also working in Dr. Griffin’s favor are his unquestioned engineering prowess and dedication to technical integrity. While he has been accused of arrogance, he never says anything that cannot be backed up with cold, hard facts. Nor will he try to do too much with too little, or make promises whose fulfillment would require rewriting the laws of physics.

And unlike the last NASA administrator, Sean O’Keefe, who ruffled some congressional feathers with an often dismissive attitude, Dr. Griffin will show lawmakers the respect that is necessary to win their support. To understand how important that is, consider that most of the current members of Congress will still be in office long after the Bush administration departs in 2009. Remember too that in 2009, the return of astronauts to the Moon will still be a decade away.

Dr. Griffin’s first major political test will come during his Senate confirmation hearing in April, where he is bound to face pointed questions about his plans for the space shuttle. The president’s exploration vision calls for retiring the fleet in 2010 after 28 more flights, but it is no secret that Dr. Griffin would like to reduce that number. That will make shuttle advocates like Sen. Kay Bailey Hutchison (R-Texas), who figure to play a prominent role in the hearing, at least nervous and wary.

But Dr. Griffin has been in the hot seat before, having served as NASA’s point man for former President George H.W. Bush’s ill-fated Space Exploration Initiative in the early 1990s. He knows what to expect, and will come prepared.

All of this is not to say that the current Bush administration, by selecting Dr. Griffin to run NASA, has assured that its own version of the Space Exploration Initiative will take flight. But it is fair to say that the White House’s choice has maximized its chances.