Jeff Morrow as Dr. Leslie Gaskell

Barbara Lawrence as Vera Hunter

George O'Hanlon as Dr. Arnold Culver

John Emery as Dr. Hubbell Eliot

Morris Ankrum as Dr. Albert Stern

Kenneth Alton as McCrary - The Pickup Driver

Jose Gonzales-Gonzales as Manuel Ramirez

Robert Forrest as KGTK-TV Newscaster

Baxter Ward as Second Newscaster

John Halloran as Lab Central Security Guard

Marjorie Stapp as Nurse

John Parrish as Gen. Perry

Don Eitner as Air Force Meteorology Sergeant

Ron Kennedy as Air Force Control Tower Sergeant

Gordon Mills as Sergeant

Rosa Turich as Manuel's Wife

Robert Shayne as Air Force General

Richard Harrison as Pilot