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Sputniks into Orbit

Tyneside, UK
2024 Jun 15
Saturday, Day 167

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Sputnik - First into Orbit

Scientists and engineers talk about Sputnik in their own words recorded at the time of the event and soon after.

Soviet Scientists Describe the First Sputnik

Sputnik 1 was spherical in shape. It was 0.579 metres in diameter and weighed 83.60 kilogrammes. Its hermetically sealed body was made of aluminium alloys, and its surface was polished and specially treated.

All its apparatus and power sources were located inside the body. Before being launched it was filled with a gaseous nitrogen.

Photo of Sputnik exhibition modelOn the outside surface, aerials were attached - four rods 2.39 metres to 2.90 metres) long. While the sputnik was being taken out to its orbit, these aerials were folded back against the body of the rocket, but after the first two steps had fallen away the aerials turned out on their hinges, assuming the position shown in the famous photo.

While travelling in its orbit, the sputnik is subjected from time to time to sharply changing heat influences - heating by the Sun's rays while on the "day" side of the Earth and cooling when flying in the Earth's shadow.

Then there is the effect of the atmosphere's heat and so on. A certain amount of heat is generated, too, when the apparatus on the sputnik is working.

As far as heat is concerned the sputnik is an independent heavenly body, exchanging radiant heat with the surrounding space. To ensure for a considerable period the normal temperature needed for the functioning of the apparatus on the satellite was, therefore, a fundamentally new and difficult problem.

The needed temperature on Sputnik I was ensured by regulating the heat resistance between the envelope and the equipment, through the forced circulation of the nitrogen in the satellite.

Two radio transmitters were installed in the sputnik, constantly emitting signals on frequencies of 20.007 and 40.002 megacycles (15 and 7.5 metre wavelengths respectively).

Date Time (UTC) Event
1957 Jan 5 In order to beat the USA into orbit, Korolyov suggests launching two small satellites during 1957, ahead of the one he originally proposed
1957 Feb 15 Soviet government agrees to Korolyov accelerated satellite programme
1957 Oct 4 19:28 World first artificial satellite Sputnik' launched from the Baikonur Cosmodrome by Sputnik (R-7) rocket into 215 x 939 kilometre orbit at 65.1 degrees inclination
1957 Oct 25 Radio transmissions from Sputnik (PS-1) cease when its electrical batteries are exhausted
1958 Jan 4 Sputnik (PS-1) enters the Earth atmosphere as a result of natural decay of the orbit through air drag, and is destroyed by frictional heating
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