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Vice President Al Gore called J.P.L. shortly after the landing to congratulate the controllers. President Clinton issued a statement hailing the occasion in more formal tones. "Our return to Mars today," he declared, "marks the beginning of a new era in the nation's space-exploration program."
There was a little hyperbole in the President's remarks, but only a little. In the past several years NASA has been quietly reinventing itself. The slow and swollen agency that grew so fat in the post-Apollo years has been painstakingly downsizing itself to something approaching the agency it was first designed to be when it was founded in the late 1950s: a crew of garage engineers cobbling spacecraft from simple parts and getting the job done both on budget and on deadline.
The results are starting to show. In September the Mars Global Surveyor, already en route to the planet, will settle into orbit and begin a two-year program of photographing and mapping the terrain below. Over the next eight years, up to eight more ships will follow. As these new probes are heading Marsward, others will be dispatched to places as familiar as the moon and as remote as Pluto. "In the next 10 years," says NASA administrator Daniel Goldin, "we'll be flying by, orbiting, landing, roving and bringing back samples from every critical planetary body in the solar system." In the wake of Friday's landing, it's hard not to believe him.
Just getting Pathfinder from Cape Canaveral to Ares Vallis required a remarkable bit of cosmic sharpshooting. Mars is only 4,200 miles across--about half as big as Earth--and the floodplain NASA was aiming for is only 60 miles wide. The barest flutter in the spacecraft's trajectory could have caused Pathfinder to swing far wide of its destination. To prevent the ship from straying too far from its ideal path, the flight plan included five different opportunities for midcourse corrections during which the spacecraft's thrusters could be fired to refine the trajectory. Over the course of the seven months the ship was en route, J.P.L. took advantage of four of those opportunities. When the time came for the fifth one early Friday morning, however, the ship was pointed so true controllers just let it fly on.
"It was a par-five hole from Earth to Mars," said a Pathfinder scientist. "And we shot a four."
Nonetheless, when Pathfinder actually reached the upper limits of Mars' wispy atmosphere, it would still have been possible for NASA to put the ship into the rough. The 1,256-lb. polyhedron-shaped pod was screaming toward the planet at 16,600 m.p.h., a speed that caused it to experience deceleration forces nearly 20 times as great as than Earth's gravity. In order to survive, the spaceship had to approach the planet at an angle of about 14.2[degrees]. "Go in too steep and you could crash and burn," says Pathfinder project scientist Matthew Golombek. "Go in too shallow and you skip back out."