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Space capsule


Unmanned Satellites and Space Probes

The first artificial satellite, Sputnik I, was launched by the Soviet Union on October. 4, 1957. Explorer I, the first American satellite, was launched on January 31, 1958. These orbited the earth. It took the launching of space probes that went out into space to get more specific information about planets and other space phenomena.

The United States and the Soviet Union launched about fifty space probes to explore the moon. They were of several types:


The Soviet Luna series were the first to accomplish each objective in the 1960s with the Luna program, including orbiting the moon.

While the American program followed behind the Soviet program, it generally revealed more scientific information with the Ranger and Surveyor programs. The Ranger program took many pictures and Surveyor program involved soft landings with television cameras placed on the moon. The Lunar Orbiter later followed which got pictures from both sides of the moon and pictures of Earth from the moon. These missions were also in preparation for a manned moon landing in the Apollo program.

Interplanetary Probes

.The US Mariner and Magellan programs studied Venus and Mars. The Soviet Venera series also studied Venus. Much was learned about the planets' surfaces and atmospheres. The American Viking program had spacecraft land on Mars. Along with the Soviet Union various European efforts via the European Space Agency and the Japanese launched efforts.

Voyagers 1 and 2, which were launched in 1977, explored Jupiter, Saturn, Uranus, and Neptune to explore all four planets. Passing as close as 3,000 miles or 4,800 kilometers to each planet's surface, the Voyagers discovered new rings, magnetic fields, and took photographs of these planets and their moons. The joint US-ESA probe Cassini, launched in 1997, will explore Saturn, its rings, and some of its moons upon arriving in 2004.



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