Changing Man's View

Not since Galileo pointed his primitive telescope at the stars some three centuries ago has man's view of the universe been so singularly changed. In its faultless flight to the moon, the purple-winged spacecraft Ranger VII kept its mechanical eyes open, its agile electronic brain functioning all through its final dive. The sharp, clear pictures it sent home to earth were more than atonement for three years of Ranger failures; they opened a path into the future as they marked the most significant achievement of the age of space.

Valuable as it was for its own discoveries, the flight of Ranger VII gave a tremendous boost to the entire U.S. space program. Gigantic rockets are already being built for manned exploration of the moon, but before a man dares to blast off, astronomers must learn the nature of the l And their biggest telescopes cannot tell them whether to expect fluffy dust or jagged rocks, smooth plains or pockmarked lava. Hampered by the turbulence of the earth's atmosphere, they can see nothing that is smaller than one mile across. Ranger VII's cameras, during their last few moments before impact on the moon, did at least 1,000 times better than that. They clearly photographed objects only 3 ft. across.

Building a Technology. To explore the moon at close hand with unmanned spacecraft is an incredibly ambitious project, far more difficult than sending a man on a few passive orbits around the earth. A Ranger spacecraft is all but alive; it maneuvers, it has eyes to watch the sun and the earth, it makes elaborate radio reports. It listens for orders, memorizes them, and carries them out at the proper time. And it must do all this in hostile space, where nothing behaves as it does on earth, where the slightest error may cause disaster.

Building such machines meant that the Jet Propulsion Laboratory in Pasadena had to build an entirely new and difficult technology. But last week's performance of Ranger VII was an intricate exercise in perfection. The Atlas booster took off from Cape Kennedy as routinely as a commuter leaving for the railroad station. After the Atlas dropped off, the Agena second stage put Ranger VII in a parking orbit, and twenty-two minutes later, the Agena fired again, giving the spacecraft the correct speed and direction to take it to a rendezvous with the moon.

Ranger was preparing itself for its long voyage. Its computer brain came to life and began issuing orders. It spread its purple wings so their silicon cells could make electricity out of sunlight. Its dish antenna unfolded; its tiny eyes (sensors) commanded tiny gas jets to turn the spacecraft so that they could bear on the sun and the earth. Its radios chattered furiously, sending reports that all was going well.

When Ranger was well settled on its course, J.P.L.'s computers figured that it would curve around the moon and hit a spot that cannot be seen from the earth. Any pictures it might take would be not much use for future astronauts, who will want to land on the visible side. A radio command was sent from J.P.L.'s Goldstone station in the Mojave Desert telling the spacecraft how to correct its course.

Maneuver. Holding the information in its electronic brain, Ranger VII went through elaborate contortions. It rolled and pitched, pointing its rocket motor almost directly ahead. Its dish antenna swung sideways out of the path of the motor's exhaust, and the motor fired for 50 seconds. Then the spacecraft returned to its original cruising attitude. After watching the new course for a while, Goldstone reported confidently that the impact point would be near the northern end of the moon's Sea of Clouds, a smooth-looking area where astronauts might land. No other maneuver would be needed.

Ill-fated Ranger VI had looked just as good as it plunged down toward the moon, but when the time came for its brain to turn on its six TV cameras, nothing happened. The spacecraft crashed on the moon as blindly as a meteorite.

This time, elaborate precautions had been taken to guard against repetitive disaster. Still, there were countless chances for trouble; space is full of demons, not all of which have been identified. At Pasadena and in tracking stations around the earth, J.P.L. men and their associates waited tensely. They knew that the spacecraft's electronic brain had been instructed to turn on its cameras at 18 minutes and 1,300 miles from the moon.

That moment came, and right on schedule loudspeakers filled the Pasadena control room with a high-pitched, quavering sound. The voice of Ranger VII was reporting that the cameras were being warmed up. A few minutes later, Project Chief Harris Schurmeier reported that the cameras were in operation. "We are receiving pictures," he said. "The signal is loud and clear." Never before had man-made eyes seen the moon so closely.

Scanned Pictures. Ranger VII carried six cameras, their lenses pointed at slightly different angles through a single hole in the side of the spacecraft. Two of them were wide-angle, to catch a broad view; the others were narrow-angle to include more detail. All of them focused their images on the faces of TV tubes about 1 in. in diameter. Whenever a camera shutter snapped, the tube held the picture on its face long enough for scanning by a hair-thin electron beam. This process produced a varying electric current that was transmitted to earth to be turned back into a replica of the picture.

The wide-angle cameras sent pictures every 2.56 sec., while the narrow-angle cameras, with their smaller images that took less time to scan, transmitted every .2 sec. The entire picture-taking apparatus, which included two radio transmitters, was made by Radio Corp. of America and weighed 382 Ibs.

All six cameras began working when Ranger was still so far from the moon that they could not show more detail than large telescopes on earth. But the distance shortened fast. The quavering sound continued in the control room on the ground, and a loudspeaker reported at intervals that all cameras were working, that the pictures promised to be good. The disembodied voice on the loudspeaker gave an informal countdown. "Video strength continues high," it said at 6:24 a.m., P.D.T. "All six cameras continue to operate. One minute to impact." With Ranger speeding toward the moon at 5,000 m.p.h., this meant that it was taking pictures about 80 miles above the surface.

Impact. It was triumph enough, but the quavering sound continued. So did the voice on the loudspeaker. "All cameras are functioning. Twenty seconds to impact. We are receiving pictures. Ten seconds to impact." At 6:25:49, the quavering signal abruptly stopped. Ranger had vanished in a puff of moon dust, sending pictures faithfully to the very end. With careful understatement, Dr. William H. Pickering, director of J.P.L., told newsmen: "We had our troubles, but it looks now as if this were a textbook operation."

How good are the 4,316 pictures? And what do they tell about the moon? J.P.L.'s scientists refused to hurry their analysis at the risk of hurting the quality of a single picture. For safety's sake, the long series of snapshots that. came into J.P.L.'s Goldstone antennas in the form of TV signals were recorded in three separate ways. First, the signals were put directly on magnetic tape that could be played back if necessary. They also energized TV picture tubes, where they looked like tiny dots of light moving in lines across the face of the tube.

This is how ordinary TV pictures are built up, but the moon shots were scanned more slowly; photographic film was needed to blend them into a pic ture. While each picture was being drawn on the tube, a kinescope camera watched, keeping its shutter open just long enough to catch one entire shot. At intervals, the engineers snapped the face of the tube with a Polaroid camera and got an instant print that gave quick assurance that all was going well.

Too valuable for any kind of hasty action, the kinescope films taken directly from the tubes were put in a refrigerator for safe storage. Then the magnetic tape was fed to an apparatus that produced pictures of slightly lower quality. It was some of these tape-recorded scenes that were shown immediately to scientists and a few hours later released to the public.

Zoom. First to get a look at the pictures was a committee of scientists headed by Astronomer Gerard P. Kuiper of the University of Arizona, a man who has spent much of his life peering at the moon through the world's best telescopes. "What has been achieved today is truly remarkable," he announced. "We have made progress in resolution not by a factor of 10, or 100, which would have been already remarkable, but by a factor of 1,000. The moon, which a good telescope can bring to a distance of 500 miles, has been brought in the Ranger experiment to a distance of half a mile."

Then Kuiper exhibited a series of ten lunar photographs. The first showed a section of the Sea of Clouds about 78 miles square. It was taken when Ranger was still 470 miles away, and Kuiper said that it showed just about as much detail as the best photographs obtainable with the biggest telescopes on earth. Picture by picture, as the spacecraft sped toward the moon, the scene expanded. Craters seemed to blossom on lunar plains that had looked perfectly smooth; in the next pictures even smaller craters appeared.

A cluster of pits showed up with edges that did not look as jagged as those of most lunar craters. As Ranger dropped lower, the clustered craters grew, and one of them showed black dots inside its rim. Nothing of the sort, said Kuiper, had ever before been seen on the moon. His guess was that the pits were made when a giant meteorite hit the moon and dug the conspicuous crater Copernicus, which is surrounded by "rays" that are believed to be splashed-out material. Astronomers used to think that this material was some sort of dust, but Kuiper now believes it contained a large number of enormous rocks. When they fell back to the moon, the rocks dug craters of their own. The black dots in one of the craters seen by Ranger are probably shadows cast by the jagged 300-ft. rock that made it and still stands inside its rim.

Three-Foot Craters. The last pictures snapped as the spacecraft sped toward the surface showed smaller and smaller craters, some of them sharp-edged pits blasted by the explosive effect of high-velocity meteors, some of them soft-edged secondary craters dug by low-speed debris from bigger impacts. The very last shot was taken when Ranger was about 1,000 ft. above the surface, and before impact the scanning beam had time to transmit only a part of it--an area 60 ft. by 100 ft. There, sharp and clear, were tiny craters no more than 3 ft. across. Careful study, said Dr. Kuiper, would almost surely show objects half as big.

The scientists were questioned eagerly about what the pictures told about the moon, but they emphasized that they had not yet seen the first-grade pictures and had taken time for only casual study of the second-grade prints. Only a few things are obvious to the expert but hasty eye. The moon's "seas" do not seem to be covered with deep, fluffy dust, as many lunar experts have argued. If they were, the little 3-ft. craters would not have steep edges. There may be a layer of soft material an inch or so thick, but Dr. Eugene Shoemaker of the U.S. Geological Survey, a former believer in deep moon dust, said that he would not hesitate to step on the moon's surface. He was not sure, however, how much weight the moon's material would support.

One important Ranger observation was the great number of small secondary craters that litter some parts of the moon. They seem to have fairly steep slopes that might topple any spacecraft that attempts to land on them. Dr. Kuiper thinks that regions splashed with rocks tossed out of big craters should be studiously avoided, but other parts of the lunar plains are probably smooth enough for landing. An encouraging sign is the comparative scarcity of small primary craters blasted by meteor impacts.

Surveyor & Orbiter. What will buoyant J.P.L. try next? Two more photographic Rangers are in preparation, and they will probably search for smooth lunar plains unscored by splashed-out rocks, and otherwise suitable for landings. Later, J.P.L.'s unmanned Surveyor spacecraft will soft-land on the moon, collect lunar material, analyze it on the spot and radio to earth reports of its chemical and physical character. For large-scale moon-mapping, J.P.L.'s Orbiter will whirl closely around the moon, transmitting thousands of pictures of its surface. With J.P.L.'s unmanned space, technology now in full flower, such feats should not be too difficult.

"There has been much speculation about the laboratory's future," said a newsman to Pickering. "What do you think of it?" "I think it's improved," he answered, and he spoke not only for his own laboratory but for all of the expensive and energetic activity that is speeding U.S. space explorers toward the reluctant moon.

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