A bomb dooms the first space satellite, manned by a selfless crew, a stowaway reporter (Lois Maxwell) and a mad scientist (Donald Wolfit).

Kieron Moore
as Cmdr. Michael Haydon

Lois Maxwell
as Kim Hamilton

Donald Wolfit
as Prof. Merrity

Bryan Forbes
as Jimmy Wheeler

Jimmy Hanley
as Larry Noble

Barry Keegan
as Lefty

Walter Hudd
as Professor Blandford

Donald Gray
as Captain Ross

Thea Gregory
as Barbara Noble

Shirley Lawrence
as Ellen