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First space satellite
The Sputnik program is the commonly known name
of a group of various robotic spacecraft missions launched by the
Soviet Union. The first of these, Sputnik 1, launched the first
human-made object to orbit the Earth. That launch took place on
October 4, 1957 as part of the International Geophysical Year and
demonstrated the viability of using artificial satellites to
explore the upper atmosphere.
The Russian word sputnik literally means
"co-traveler", "traveling companion" or "satellite", and the
satellite's R-7 launch vehicle was designed initially to carry
nuclear warheads.
satellite was 58 cm (about 23 in) in diameter
and weighed approximately 83.6 kg (about 183 lb). Each of its 1440
elliptical orbits around the Earth took about 96 minutes.
Monitoring of the satellite was done by many amateur radio
operators and the Jodrell Bank Observatory. Sputnik's R-7 booster
had previously proven itself more than one month earlier as the
world's first ICBM in the successful long-range test flight of
August 21 (with the accomplishment published in Aviation Week).
Sputnik 1 was not visible from the Earth but the casing of the R-7
booster, traveling behind it, was visible.
Sputnik 2 was launched on November 3, 1957, and
it carried the first living passenger into orbit, a female dog
named Laika. The mission planners did not provide for the safe
atmospheric re-entry of the spacecraft or its living passenger,
making Laika the first orbital spaceflight casualty.
The first attempt to launch Sputnik 3, on April
27, 1958, failed, but the second on May 15 succeeded, and it
carried a large array of instruments for geophysical research. Its
tape recorder failed, however, making it unable to measure the Van
Allen radiation belts.
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