NASA's departing boss, Sean O'Keefe, said Friday he does not regret canceling the last shuttle mission to the Hubble Space Telescope — or anything else during his three years on the job.
He also said NASA is stronger, reports CBS News Correspondent Peter King, thanks to the long range goal of returning to the Moon and going on to Mars.
"There's a lot on the plate, a lot of neat things to do, and yet there's a very good strategy laid out, and a very clear game plan," O'Keefe said.
O'Keefe's decision nearly a year ago prohibiting astronauts from repairing the Hubble, on post-Columbia safety grounds, was by far his most controversial and was challenged by a prestigious scientific panel just last week.
"The decision that I made I intend to stand by," O'Keefe said at a news conference. He said a pair of design reviews for a potential robotic mission to prolong Hubble's life, scheduled for March and August, "will tell us a lot more about this rather than guessing."
Unless astronauts or robots get to Hubble within a few years to install fresh batteries, gyroscopes and other equipment, its breathtaking observations of the cosmos will cease.
"I don't know that there's a whole lot that I would have done differently," O'Keefe said. "I don't spend any amount of time, I've got to tell you flat out, really thinking about woulda, coulda, shoulda's and looking backward. Every minute you spend looking backward is time wasted from not looking forward."
O'Keefe met with reporters and then formally addressed NASA employees for the first time since resigning Monday. On Thursday, he was selected as the new chancellor of Louisiana State University. He will remain at NASA until his successor is chosen.
He said it was appropriate for his yet-to-be-selected successor to preside over the space shuttle's return to flight in late spring, since that is the first step in President Bush's plan to send astronauts back to the moon and on to Mars.
"This was about exploration and about yielding to the desire we all have, I think, to understand and to explore and understand better what we don't know," O'Keefe said.
In a speech televised at NASA centers nationwide, O'Keefe assured employees that his decision to leave NASA was with mixed emotions and based on family considerations. The father of three teenagers, the oldest of whom will go off to college next fall, will more than triple his $158,000 annual government salary at LSU.
He recalled the "wonderful high moments" of landing two rovers on Mars and helping to develop the president's space exploration plan.
He also reflected on the heartbreak of last year's Columbia accident and told employees that "if history is any guide," there will be more triumph ahead — and probably tragedy, too.
And he revealed one of the lessons he learned as head of NASA:
"Never, never, never, follow an astronaut on the stage, OK? It's the equivalent of being the dog act after the main event," O'Keefe said.