Sarath

Sarath was a planet visited by the First Doctor, Susan Foreman, Ian Chesterton and Barbara Wright. The inhabitants were humans who didn't realise that they had travelled through space before because of a hazy history. The planet was soon to be destroyed by pieces of the Sarath Moon breaking up and crashing to the surface. The humans were forced to build a rocket so that they could escape. (PDA: City at World's End)