Russian `fellow traveller' a series of ten
Soviet Earth-orbiting satellites. Sputnik 1
was the first artificial satellite, launched
4 Oct 1957. It weighed 84 kg/185 lb, with a
58 cm/23 in diameter, and carried only a
simple radio transmitter which allowed
scientists to track it as it orbited Earth.
It burned up in the atmosphere 92 days later.
Sputnik 2, launched 3 Nov 1957, weighed about
500 kg/1,100 lb including the dog Laika, the
first living creature in space.
Unfortunately, there was no way to return the
dog to Earth, and it died in space.