Fred F. Sears Director Hugh Marlowe Dr. Russell A. Marvin Actor Joan Taylor Carol Marvin Actor Donald Curtis Maj. Huglin Actor Morris Ankrum Brig. Gen. Hanley Actor Thomas Henry Vice Adm. Enright Actor John Zaremba Prof. Kanter Actor Grandon Rhodes Gen. Edmunds Actor Larry J. Blake Motorcycle cop Actor Harry Lauter Cutting, Generator technician Actor Charles Evans Dr. Alberts Actor Clark Howat Sgt. Nash Actor Alan Reynolds Major Kimberly Actor Donald E. Keyhoe Writer Curt Siodmak Writer George Worthing Yates Writer Bernard Gordon Writer Sam Katzman Executive Producer Charles H. Schneer Producer Mischa Bakaleinikoff Original Music Fred Jackman Jr. Cinematographer Danny B. Landres Film Editing Paul Palmentola Production Design Sidney Clifford Set Decoration