The ungainly gadget carried no human passengers. But as it eased its complex cargo to a soft landing on the moon's Ocean of Storms last week, the U.S. spacecraft, Surveyor I, moved man himself closer than ever to a landing on his nearest planetary neighbor. In an exercise of textbook perfection, Surveyor settled down only a few miles from its planned target; its TV camera panned across the lunar landscape and high-quality pictures streamed back to earth. For a program that had languished for years in exasperating delay, expanding expenses and mounting criticism, the very first payoff was perfection.
For the scientists at the Jet Propulsion Laboratory control center in Pasadena, the difficult task of nursing Surveyor to a point 60 miles above the moon's surface was far less harrowing than the final phase of the trip. For in the long moments of the last drop, Surveyor's own computers and radar were issuing the necessary orders. And back on earth, 230,930 miles away, the craft's creators could do no moreno more than pray that their design and pre-launch calculations were all correct.
Cushioning the Jolt. They were, Small vernier rockets near each of the craft's three legs fired to stabilize the spacecraft in a base-down attitude. When the radar sensed that Surveyor was precisely 52 miles above the moon, it fired a powerful, solid-fuel retrorocket that slowed the craft from 5,840 m.p.h. to only 267 m.p.h. in 40 seconds.
At a lunar altitude of 25,000 ft., the retrorocket was jettisoned and the vernier rockets took over the job of further reducing speed, stabilizing and gently guiding Surveyor along the proper trajectory toward its impact point. When it was 13 ft. above the lunar surface and descending at 3.3 m.p.h., the 620-lb. Surveyor shut down its verniers and fell the remaining distance. It struck the moon no harder than a parachutist hits the earth. And even this relatively small jolt was cushioned by hydraulic shock absorbers and crushable aluminum pads under Surveyor's legs and body.
As telemetry confirmed that the landing was proceeding according to plan, scientists and spectators at the JPL control center first stared in apparent disbelief. They were well aware that the Russians had failed at least four times before landing an instrument package intact on the moon and that the first seven of the ten planned Surveyor shots had been designated "engineering flights"a tacit admission that U.S. scientists expected many failures before a successful soft landing was achieved. But when telemetry continued after impactevidence that Surveyor had survived the landingdisbelief gave way to wild cheering. Half an hour later, on radioed command, the craft's television camera began to take its first pictures.