Edmond O'Brien
General Carter
Donald Pleasence
Dr. Michaels
Arthur O'Connell
Col. Donald Reid
William Redfield
Capt. Bill Owens
Barry Coe
Communications Aide
Brendan Fitzgerald
Wireless Operator
Brendon Boone
Military Policeman (uncredited)
James Doohan
Dr. Sawyer (Hypothermia technician) (uncredited)
Kenneth MacDonald
Henry - Heart Monitoring (uncredited)
Christopher Riordan
Young Scientist (uncredited)