The first artificial Earth satellite is one of the greatest achievements of twentieth-century science. Nevertheless, paradoxically, this great scientific and technological achievement was greatly facilitated by the Cold War between the two superpowers: the United States and the Soviet Union. The launch of the first artificial Earth satellite was also necessary for the growing need to obtain reliable information about the upper atmosphere, the possibility of transmitting a radio signal from orbit, etc.
In the early 1950s, both the United States and the USSR actively developed rockets for the space program. In particular, in May 1954, the chief designer of the space program of the Soviet Union Sergey Korolev met with the Minister of Defense of the USSR Dmitry Ustinov and reported that the first artificial Earth satellite could be launched into orbit. A similar statement was made on July 29, 1955 by the President of the United States, Dwight Eisenhower, while he indicated the dates between 1957 and 1958.
In early August 1955, the Politburo of the CPSU Central Committee approved the creation of the first Earth satellite. This project was led by Korolev, as well as Vasily Ryabikov, who oversaw the test launches of the R-7 rocket. For launch, the simplest first Earth satellite with two beacons on board was developed.
Satellite No. 1 was a 585 mm sphere covered with a heat shield consisting of aluminum, magnesium and titanium. It was equipped with four long antennas that were capable of transmitting simple audio signals to the Earth's surface in two frequencies. The first artificial Earth satellite was also equipped with three silver-zinc batteries, which could work for two weeks. The temperature control system was a radiator with a fan, a sealed circuit, a forced heat exchange system designed to maintain a stable internal temperature. This system used bimetal thermal relays as a sensing element. Whenever the temperature rose above 36 ° C, the fan was turned on, and nitrogen circulated through the heat transfer system from the hemispheres. When the temperature dropped below 20 ° C, the fan turned off.
Sputnik-1 was launched on October 4, 1957. 295.4 seconds after launch, the first artificial Earth satellite was launched into orbit. It was just the third successful flight of the R-7 rocket, which was created for an intercontinental flight with a thermonuclear hydrogen bomb. The satellite developed the first space velocity calculated by Newton. It was 7780 m / s. He completed a complete revolution in 96.2 minutes. Despite the fact that it was developed in just two weeks, the mission lasted 22 days until the batteries were empty. Radio amateurs from around the world followed the sound signals transmitted by the satellite. It could be observed - like a star of the first magnitude - even with the naked eye. The satellite descended from orbit and burned out in the atmosphere on January 4, 1958.
The American public and the media were so surprised by the technological breakthrough of the USSR that a wave of paranoia swept through the United States. The political and public reaction to the publication of the TASS message was unexpected for the USSR. Thus, replacing the thermonuclear hydrogen bomb with a small satellite, the Soviet Union won a significant political and social victory.
The satellite crisis has led to the creation of Advanced Research Projects Agency and NASA in the United States, as well as a significant increase in government spending on education and research.
The United States was able to launch its first artificial satellite Explorer-1 on January 31, 1958. It was a cylindrical spacecraft with a diameter of 15 cm and a length of 203 cm with a mass of 14 kg. He transmitted data on the measurement of cosmic rays and on the level of radiation for 112 days. These data led to the discovery of the Van Allen belt.
Since 1957, about 7,000 satellites have been launched into Earth’s orbit, most of which are already out of order and present a real obstacle to further space exploration.