Steve Railsback as Col. Tom Carlsen

Peter Firth as Col. Colin Caine

Frank Finlay as Dr. Hans Fallada

Mathilda May as Space Girl

Patrick Stewart as Dr. Armstrong

Michael Gothard as Dr. Bukovsky

Nicholas Ball as Roger Derebridge

Aubrey Morris as Sir Percy Heseltine

Nancy Paul as Ellen Donaldson

John Hallam as Lamson

John Keegan as Guard

Bill Malin as Second Vampire

Derek Benfield as Physician

Jerome Willis as Pathologist

John Woodnutt as Metallurgist

John Forbes-Robertson as The Minister

Peter Porteous as Prime Minister

Katherine Schofield as Prime Minister's Secretary

Owen Holder as First Scientist

Jamie Roberts as Rawlings

Russell Sommers as Navigation Officer

Patrick Connor as Fatherly Guard

Sidney Kean as Brash Guard

Paul Cooper as Second Guard

Chris Sullivan as Kelly

Burnell Tucker as N.A.S.A. Man

Chris Jagger as First Vampire

Barrie Holland as London Man (uncredited)

John Larroquette as Narrator (uncredited)