Russian, literally 'fellow-traveller'.

• satellite from mid 16th century:

  In 1611 the German astronomer Johannes Kepler, writing in Latin, gave the name satellites to the moons of Jupiter, which Galileo had recently discovered. An English publication referred to ‘a Satellite of Jupiter’ in 1665. In Latin satelles, of which satellites is the plural, meant ‘an attendant or guard’, a use occasionally found in English from the mid 16th century, usually with overtones of subservience or fawning attentiveness. Until the 1930s the only satellites in space were natural bodies such as planets and moons, but in 1936 the word was first applied to a man-made object (at that point just a theoretical one) put into orbit around the earth. The first artificial satellite to be launched was the Russian Sputnik 1, in 1957, and in 1962 the Telstar satellite relayed the first satellite television signal. Sputnik means ‘fellow traveller’ in Russian, while Telstar got its name because it was built by Bell Telephone Laboratories and used for telecommunications.