NASA chief on mission

— -- By the time Sputnik began circling the Earth, Michael Griffin was already a space buff who understood how a satellite stays in orbit.

"I remember explaining that to my teacher" after Sputnik's launch, he says. He was 8.

Now 58, Griffin directs the world's largest space agency. As the administrator of NASA, he is struggling to ensure the United States can claim unquestioned supremacy in space.

He now regrets calling the space shuttle a mistake in 2005. The real mistake, he says, was the White House's decision in the early 1970s to confine America's human space program to Earth's orbit.

"We've wasted a lot of time," Griffin says. "Do I wish we could send people to Mars right now? The only answer I could give you would be, 'Yes.' But we can't."

The frustration is evident in his voice as Griffin offers his views of why astronauts have explored less of the solar system in the past 38 years than they did in the 12 years after Sputnik.

At the end of the Apollo program that put man on the moon, "we had an enormous amount of capability on hand," he says. "We could have been on Mars by the early 1980s, mid-1980s at the latest."

Instead, the last few Apollo flights were canceled and the spacecraft assembly lines shut. Americans did not protest, which Griffin attributes partly to the same factor that drove America to the moon.

"We created Apollo but, because we viewed it only as a race, we gave ourselves permission to throw it away" after winning, he says. "Overall, I think races hurt us."

He gets testy at the suggestion that Americans might not want to fund the effort to send astronauts back to the moon and on to Mars. His plan, he says, does not require an increase in NASA's budget.

"I would hope that the American people and … any American president (are) way smarter than" those who cut back human spaceflight in the 1970s, he says.

"That's a mistake we made once. Let's not make it again."