Commander Jack Rankin
Dr. Lisa Benson
Commander Vince Elliott
General Jonathan B. Thompson (as Bud Widham)
Dr. Hans Halvorsen
Lt. Curtis
Capt. Martin
Cordier
Lt. Morris, Rocket Pilot
Technician
Nurse
Michaels (as Richard Highland)
Rocket Pilot (as Carl Bengs)
Doctor
Lt. Scott, Rocket Pilot
Medical Office Staff member (uncredited)
Sergeant (uncredited)
Rocketship Member (uncredited)
Secretary (uncredited)
Technician (uncredited)
Space station crew member (uncredited)
Patient (uncredited)
Alien creature (uncredited)
Nurse (uncredited)
(voice) (uncredited)
Soldier (uncredited)
Space station crew member. (uncredited)
Ferguson (uncredited)
Officer (uncredited)
Barnett (uncredited)