Det här låter som Earthsearch av James Follett, första sändningen på BBC Radio 4 1981 / 1982, men kanske upprepas senare.
Det finns en liten grupp ungdomar på rymdskepp, deras liv drivs av datorer:
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. [...] the ruthless, manipulative control of the Challenger's megalomaniacal control computers, Angel One and Angel Two.
Och det finns en enorm struktur som de behöver för att lösa ett pussel för att komma in i:
The only sign of life is a huge ten-mile-high tower on the equator, with a tiny village nearby. [...] The crew examine the tower, finding that there is a door set into one side which cannot be opened. Peeron says that many of his predecessors have made attempts over the centuries – for example, by hitting the door with battering rams – but it will not budge. It is said that it is held shut by a "lock of knowledge". Darv eventually works out how to open the ingeniously simple lock, which requires a low grade of technology which would only be available to people who have already worked out basic principles of science and engineering.
(Citat från Wikipedia-artikeln.)