Brian Cooper may be the slowest driver in the solar system. Floored, his vehicle reaches a sustained velocity of a tenth of a mile per hour. That's fine with Cooper, who fears getting stuck in the bottom of a crater. On Mars you can't call a tow truck.
On a recent morning, Cooper's vehicle, the rover named Opportunity, stood parked on the downward slope of a crater the size of a football field. On his computer here at NASA's Jet Propulsion Laboratory, Cooper could see what the rover saw through its stereoscopic cameras. Toward the bottom of the crater, where the surface leveled out, the rocky ground gave way to softer soil. Trouble.
Cooper wanted to tell the rover to take this opportunity to turn the heck around and get out of the crater. But scientists wanted the rover to keep going down, deeper into the planet's geological past. They won the argument.
"I'm just one little voice of caution. Our job is to make sure the rover is safe to drive another day," Cooper said. "We never go fun-truckin'."
He's an engineer, and engineers know better than anyone the limits of their contraptions. He does a great imitation of Scotty from "Star Trek":
"It can't take it ennymore, Cap'n!"
The triumphs of two rambling rovers on Mars, as well as the success of the Cassini spacecraft that recently reached Saturn, prove that NASA still knows how to perform magic in space. But it is simultaneously a traumatized agency, struggling to maintain the dream of the Apollo era. The space shuttle fleet remains grounded as a result of the Columbia disaster. The International Space Station orbits the Earth aimlessly, an expensive contraption that remains unfinished, with two lonely astronauts laboring to keep it from falling apart.
Earlier this year, President Bush endorsed a bold plan to return astronauts to the moon and eventually send them to Mars. This "Vision for Space Exploration" would allow NASA to retire the aging shuttles and eventually put the space station out to pasture. Space buffs are excited by the prospect of getting beyond Low Earth Orbit again. But Congress hasn't rushed forward with money for a moonshot or a Mars mission. The last such ambitious onward-to-Mars proposal, the Space Exploration Initiative of the first President Bush, went nowhere when Congress saw the price tag. Even this President Bush, days after unveiling the plan in January, declined to say a word about it in his State of the Union Address. It was as though sending men to Mars was a momentary brainstorm, one of those ideas that seems great at midnight and is quickly forgotten the next morning.
There has been one dazzling feat of human spaceflight in recent months, but it was a private venture, a piloted rocket-plane that bored a hole in the sky, touched the edge of space more than 300,000 feet up and safely returned to Earth.
The government, meanwhile, hasn't yet figured out how to keep one of its signature triumphs, the Hubble Space Telescope, from falling back to Earth in a fireball. NASA doesn't want to endanger a crew of astronauts for the sake of an aging instrument that will eventually be replaced by more powerful telescopes. There is talk of a robotic mission to save the Hubble, but the whole issue has been a public relations disaster for the agency, emanating the whiff of a can't-do attitude. These were the people who could always do the impossible. They were the ones who inspired a great American cliche: If we can put a man on the moon, why can't we . . .
Even here at JPL, past disasters keep everyone from feeling overconfident. People know that spaceflight remains a difficult, experimental, chancy line of work.
"The shadow of failure is around the corner all the time," says Charles Elachi, JPL's director.
Robotic spaceflight and space-based astronomy, using a new generation of telescopes, may be the likeliest source of NASA glory for the next decade or so. But space science has never been the central purpose of NASA. NASA has always been powered by the dream that humans, and not just their robotic proxies, will directly explore the universe.