Episode 55 we look at The Starlost ( okay we never heard of it either ).

This 1973 show stars Keir Dullea ( 2001's Dave Bowman ( this show is not full of stars )).

Foreseeing the destruction of the Earth, humanity builds a multi-generational starship called Earthship Ark, 50 miles (80 km) wide and 200 miles (320 km) long. The ship contains dozens of biospheres, each kilometres across and housing people of different cultures.