either of two low-altitude active communications satellites launched in 1962 and 1963 by the US and used in the transmission of television programmes, telephone messages, etc
Telstar in American English
(ˈtɛlˌstɑr)
US
noun
either of two experimental communications satellites used between July 10, 1962, and May, 1965, to amplify and relay various signals, esp. television, across the oceans