On July 10, 1962, the satellite Telstar 1, the first telecommunications satellite, was launched.
Telstar 1 was the result of an international collaboration that for the first time also included private companies. In fact, this satellite was built by Bell Telephone Laboratories – in short, Bell Labs – which was then a research and development laboratory of AT&T, which for decades brought many technological innovations important in the present world.
The satellite Telstar 1 had an approximately spherical shape with a diameter of almost 88 cm (34.5 inches) and a weight of about 77 kg (170 pounds). The size was limited because the satellite needed to fit on the Thor-Delta rocket that would launch it. Telstar 1 was covered by 3,600 solar cells, also invented by Bell Telephone Laboratories in 1954, which produced a power of 14 watts.
The satellite Telstar 1 was equipped with an innovative transponder capable of relaying a black and white television channel on either side of the Atlantic Ocean. It could also relay six hundred telephone calls.
The orbit of the satellite Telstar 1 was elliptical and not geostationary, unlike most modern satellites which generally have a circular and geostationary orbit. Each orbit was completed in 2 hours and 37 minutes and this meant that Telstar 1 could only relay signals for 20 minutes for each orbit when it passed over the Atlantic Ocean. The antennas on the ground had to follow the movements of Telstar 1 for must capture the signals and had to be much larger than the ones used today because of a signal power much lower than in the following generations of satellites.
Unfortunately, at the time both the U.S.A. and the USSR were making high-altitude nuclear tests, and explosions released large amounts of radiation also in the area where the satellite Telstar 1 passed through. Consequently, in December 1962 there was the first failure but in that case, the satellite functions were restored. In February 1963 there was a second failure and this time it wasn’t possible to make Telstar 1 work again using other circuits.
Despite the limitations of the satellite Telstar 1 and its short life, the ability to relay television and telephone signals across the Atlantic was too important. Therefore, in the following years, other more and more sophisticated communications satellites were placed in orbit.
Today we take for granted the possibility to watch live television broadcasts from anywhere in the world but this is possible thanks to a series of technological advancements that started fifty years ago with the satellite Telstar 1.
