Today, there are thousands of artificial satellites orbiting Earth; so many, in fact, that debris is becoming a significant problem for space activities and there are fears that it might eventually prevent us from doing anything in low Earth orbit. But it was sixty years ago today that the age of the satellite actually began: on 4th October 1957, the very first artificial satellite was launched from what is now the Baikonur Cosmodrome in Kazakhstan. Its name was Sputnik 1.
To celebrate the anniversary, here are seven facts about this 83-kilogram pioneer.
1. When the Soviet Union made the decision to launch a satellite for the International Geophysical Year (July 1957 – December 1958), the original first satellite – named Object D – was intended to weigh more than a ton and carry a large assortment of scientific instruments. When Object D fell behind schedule, however, it was decided instead to fly a much simpler satellite first, rather than run the risk of the United States beating the Soviet Union into space. The resulting satellite was Sputnik 1, whose name means “fellow traveller”.
2. Weighing 83 kilograms, and with a diameter of 58.5cm, Sputnik 1 consisted simply of a metal sphere with four antennas, batteries, equipment for regulating temperature and monitoring internal pressure, and a radio transmitter. While relatively small, it was still much larger than the United States’ intended first satellite, Vanguard, which weighed 1.4kg.
3. Sputnik 1 was launched using an R-7 rocket, which had originally been designed as an intercontinental ballistic missile capable of delivering nuclear warheads to America. A variant on the R-7 is still used today to launch Soyuz spacecraft to the International Space Station.
4. Sputnik 1 did not carry any proper scientific instruments, but scientists were still able to learn from it: the density of the upper atmosphere could be analysed from the behaviour of its radio signals, and the rate at which its orbit decayed.
5. People all over the world were able to observe Sputnik 1 as it crossed the night sky, but they weren’t actually seeing the satellite itself, which was too small to be viewed with the naked eye. What they actually saw was the much larger rocket booster which placed the satellite in orbit, then continued to follow it through space.
6. The fact that the Soviet Union had launched the first satellite came as a great shock to the United States. It even led the US Government to direct more money into scientific education, in the hopes of addressing the country’s apparent inadequacy.
7. Radio contact with Sputnik 1 was lost on 26th October 1957 when its batteries died. The satellite burned up in the atmosphere on 4th January 1958, having completed over 1400 orbits of the Earth.