Science: Onward from Venus

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Even as the Apollo 14 astronauts went through final preparations last week for their mission to the moon, word of a remarkable Soviet achievement raised further doubts about U.S. emphasis on costly and risky manned space flights. In Moscow, Russian scientists belatedly revealed that the unmanned space probe Venera 7, which reached Venus on Dec. 15, had survived its descent through the murky Venusian atmosphere and continued to function after landing. Its radio transmissions carried the first scientific data to be transmitted to earth from the surface of another planet.

Venera 7 remained alive for 23 minutes on the hostile surface of Venus, confirming what data from earlier U.S. and Soviet probes had suggested: that the temperature stayed about 900° F. and that atmospheric pressure was around 90 times as high as terrestrial sea-level pressure. Then Venera fell silent, its instruments presumably cooked by the intense heat. That the craft survived as long as it did was a testimonial to the increasing sophistication of the Soviet space program. Venera 7 was the 17th Soviet mission to Venus.* Although the last three probes were on target, deployed parachutes and transmitted data after entering the planet's atmosphere, none reached the surface in operating condition; they were either crushed or overheated while floating down through the dense, broiling atmosphere.

Faint Signals. Russian scientists had redesigned the Venera spacecraft to withstand pressures of 150 earth atmospheres and temperatures in excess of 1000° F. They also redesigned their parachute (probably made of steel mesh) to enable Venera to descend more rapidly to the surface. To allow for the higher landing velocity, they incorporated a shock-absorbing landing gear.

Why had the Soviets delayed so long in reporting the triumph? Western experts speculated that they were being cautious in analyzing Venera's faint signals. The Russians were embarrassed, after the flight of Venera 4, when U.S. scientists correctly disputed their claims that the craft's radio had operated until it reached the surface.

This time there was no dispute. Acting NASA Administrator George Low praised Venera's mission as "a significant achievement." And Dr. Charles Sheldon, the Library of Congress expert on the Soviet space program, predicted that the Russians would now launch a modified version of Venera, perhaps as early as April, in an effort to make a soft landing on Mars. That could put the Russians four years ahead of the U.S., which now has no plans for an unmanned landing on Mars before 1975.

* Only four U.S. unmanned shots, all of them flybys, have been sent to Venus.