The History of Satellites - Sputnik I

Sputnik Model
Staffan Vilcans/Flickr/CC BY-SA 2.0

History was made on October 4, 1957 when the Soviet Union successfully launched Sputnik I. The world's first artificial satellite was about the size of a basketball and weighed only 183 pounds. It took about 98 minutes for Sputnik I to orbit the Earth on its elliptical path. The launch ushered in new political, military, technological and scientific developments and marked the beginning of the space race between the U.S.and the U.S.S.R.

The International Geophysical Year

In 1952, the International Council of Scientific Unions decided to establish the International Geophysical Year. It wasn't actually a year but rather more like 18 months, set from July 1, ​1957 to December 31, 1958. Scientists knew that cycles of solar activity would be at a high point at this time. The Council adopted a resolution in October 1954 calling for artificial satellites to be launched during the IGY to map the earth's surface.

The U.S. Contribution 

The White House announced plans to launch an earth-orbiting satellite for the IGY in July 1955. The government solicited proposals from various research agencies to undertake development of this satellite. NSC 5520, the Draft Statement of Policy on U.S. Scientific Satellite Program, recommended both the creation of a scientific satellite program as well as the development of satellites for reconnaissance purposes.

The National Security Council approved the IGY satellite on May 26, 1955 based on NSC 5520. This event was announced to the public on July 28 during an oral briefing at the White House. The government's statement emphasized that the satellite program was intended to be the U.S. contribution to the IGY and that the scientific data was to benefit scientists of all nations.

The Naval Research Laboratory's Vanguard proposal for a satellite was chosen in September 1955 to represent the U.S.during the IGY. 

Then Came Sputnik I 

The Sputnik launch changed everything. As a technical achievement, it caught the world's attention and the American public off guard. Its size was more impressive than Vanguard's intended 3.5-pound payload. The public reacted with fear that the Soviets' ability to launch such a satellite would translate to the ability to launch ballistic missiles that could carry nuclear weapons from Europe to the U.S.

Then the Soviets struck again: Sputnik II was launched on November 3, carrying a much heavier payload and a dog named Laika.

The U.S. Response

The U.S. Defense Department responded to the political and public furor over the Sputnik satellites by approving funding for another U.S. satellite project. As a simultaneous alternative to Vanguard, Wernher von Braun and his Army Redstone Arsenal team began work on a satellite that would become known as Explorer.

The tide of the space race changed on January 31,  1958 when the U.S. successfully launched Satellite 1958 Alpha, familiarly known as Explorer I. This satellite carried a small scientific payload that eventually discovered magnetic radiation belts around the Earth.

These belts were named after principal investigator James Van Allen. The Explorer program continued as a successful ongoing series of lightweight, scientifically-useful spacecraft. 

The Creation of NASA

The Sputnik launch also led to the creation of NASA, the National Aeronautics and Space Administration. Congress passed the National Aeronautics and Space Act, commonly called the "Space Act,” in July 1958, and the Space Act created NASA effective October 1, 1958. It joined NACA, the National Advisory Committee for Aeronautics, with other government agencies.

NASA went on to do pioneering work in space applications, such as communications satellites, in the 1960s. The Echo, Telstar, Relay and Syncom satellites were built by NASA or by the private sector based on significant NASA advances.

In the 1970s, NASA's Landsat program literally changed the way we look at our planet.

The first three Landsat satellites were launched in 1972, 1975 and 1978. They transmitted complex data streams back to earth that could be converted into colored pictures.

Landsat data has been used in a variety of practical commercial applications since then, including crop management and fault line detection. It tracks many kinds of weather, such as droughts, forest fires and ice floes. NASA has also been involved in a variety of other earth science efforts as well, such as the Earth Observation System of spacecraft and data processing that has yielded important scientific results in tropical deforestation, global warming and climate change.