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Early Landings
Venera 3 the Soviet space probe
crash-landed on Venus, becoming the first spacecraft
to arrive at the planet's surface in 1966 of March
1. Its sister craft Venera 2 had failed from overheating
shortly before completing its flyby mission.
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The descent capsule of Venera 4 entered
the atmosphere of Venus on October 18, 1967.
The first probe to return direct measurements
from another planet, the capsule deliberated
temperature, pressure, density and performed
11 automatic chemical experiments to examine
the atmosphere. It showed 95% carbon dioxide,
and in combination with radio supernatural
data from the Mariner 5 probe, it showed that
surface pressures were far greater than expected
(75 to 100 atmospheres). |
These results were confirmed
and refined by the Venera 5 and Venera 6 missions
on May 16 and 17 of 1969. However none of these
missions had reached the surface whereas still
transmitting. Venera 4's battery ran out while
gradually floating through the massive atmosphere,
and Venera 5 and 6 were crushed by high pressure
18 km (60,000 ft) above the surface.
The first successful landing on Venus was by Venera
7 on December 15, 1970. It relayed surface temperatures
of 455 °C to 475 °C (855 °F to 885
°F). Venera 8 landed on July 22, 1972. Besides
pressure and temperature profiles, a photometer
showed that the clouds of Venus formed a layer,
ending over 22 miles above the surface. A gamma
ray spectrometer analyzed the chemical composition
of the crust.
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