Earthsearch: (10-Part Serial in Time and Space)

Earthsearch: A Ten-Part Adventure Serial in Time and Space is a science fiction radio series written by James Follett. It consists of ten half-hour episodes. It was first broadcast on BBC Radio 4 between January and March 1981.
Three crew-generations previously, the starship Challenger - a vast ten-mile-long survey vessel – was launched from Earth on an interstellar mission to search the universe for an Earth-type planet to colonise. This has been unsuccessful, and the ship's once enormous crew-count has now been reduced to four. Telson (the ship's Commander), Sharna (Science officer), Darv and Astra are the third-generation crew- the only survivors of the disastrous Great Meteoroid Strike which seriously damaged the ship two decades previously, killing the entire second-generation crew and rendering large areas of the ship "uncontrolled" and inaccessible to its electronic systems.

From infancy, the four third-generation crew members (now in their early twenties) have been raised by robots and by the Angels – mysterious unseen beings who run the ship and who only manifest as disembodied voices. Darv, the most skeptical and enquiring of the crew members, suspects that the Angels are merely computers; but the others consider them as "Guardian Angels" and work entirely under their guidance.