Sputnik

Sputnik

Sputnik is the name given to a series of scientific research satellites launched by the Soviet Union during the period from 1957 to 1961. The satellites ranged in size and capability from the 83.6-kilogram (184.3-pound) Sputnik 1, which served only as a limited radio transmitter, to Sputnik 10, which weighed 4,695 kilograms (10,350 pounds). Together the Sputnik flights ushered in the space age and began the exploration of space by orbital satellites and humans. Sputnik 1 is the most famous in the series.

In August 1957 the Soviet Union conducted a successful test flight of a stage-and-a-half liquid-fueled intercontinental ballistic missile called the R-7. Shortly thereafter Soviet scientists were quoted in the news media inside the Soviet Union saying that they were planning for the launch of an Earth satellite using a newly developed missile. Western observers scoffed at the accounts. In the late summer of 1957 Soviet scientists told a planning session of the International Geophysical Year celebrations that a scientific satellite was going to be placed into orbit, and they released to the press the radio frequency that the satellite would use to transmit signals. Again, the statements were widely dismissed inside the United States as Soviet propaganda.

Late in the evening in the United States (Eastern Standard Time) on Friday, October 4, 1957, Radio Moscow announced that a small satellite designated Sputnik 1 had been launched and had successfully achieved orbital flight around Earth. The U.S. Defense Department confirmed the fact shortly after the reports reached the West.

Sputnik 1 was the first artificial satellite to reach orbit. Launched from a secret rocket base in the Ural Mountains in Soviet central Asia, it weighed 83.6 kilograms (184.3 pounds), was 0.58 meter (1.9 feet) wide, and carried four whip-style radio antennas that measured 1.5 to 2.9 meters (4.9 to 9.5 feet) in length. Aboard the tiny satellite were instruments capable of measuring the thickness and temperature of the high upper atmosphere and the composition of the ionosphere , and the satellite was also capable of transmitting radio signals. The Soviet news agency Tass released the final radio frequency of the Sputnik and the timetables of its broadcasts, which were widely disseminated by news media worldwide. Sputnik 1 transmitted for twenty-one days after reaching orbit and remained in orbit for ninety-six days. It burned up in the atmosphere on its 1,400th orbit of Earth.

Sputnik 2 was launched into orbit a month later on November 3, 1957. It was a much larger satellite, weighing 508 kilograms (1,120 pounds), and contained the first living creature to be orbited, a dog named Laika. The dog, its capsule, and the upper part of the rocket that launched it remained attached in space for 103 days before burning up after making 2,370 orbits. However, there was only enough oxygen, food, and water to keep Laika alive for a week. There were no provisions to either save the dog or return its capsule to Earth.

Sputniks 3 through 10 were research craft aimed at obtaining design data for the construction of a human-carrying spacecraft. Sputnik 3 was launched on May 15, 1958, Sputnik 4 on May 15, 1960, Sputnik 5 on August 19, 1960, Sputnik 6 on December 1, 1960, Sputnik 7 on February 4, 1961, Sputnik 8 on February 12, 1961, Sputnik 9 on March 9, 1961, and Sputnik 10 on March 25, 1961. Sputnik 10 was a full test version of the Vostok human-carrying space capsule, which carried the first human into space two weeks later on April 12, 1961. Sputniks 5, 6, 9, and 10 carried dogs. Sputnik 10's canine passenger, Zvezdochka, was successfully recovered. Sputnik designations were briefly given to a series of interplanetary probes but these were renamed as part of the Luna series in 1962 and 1963.

see also Animals (volume 3); International Space Station (volume 1 and volume 3); Satellites, Types of (volume 1); Space Shuttle (volume 3).

Frank Sietzen, Jr.

Internet Resources

"Sputnik and the Dawn of the Space Age." NASA Headquarters. <http://www.hq.nasa.gov/office/pao/History/sputnik/>.