Gregory Peck
Charles Keith
David Janssen
Ted Dougherty
James Franciscus
Clayton Stone
Mariette Hartley
Betty Lloyd
Scott Brady
Public Affairs Officer
Frank Marth
Air Force Systems Director
Craig Huebing
Flight Director
John Carter
Flight Surgeon
Vincent Van Lynn
Aerospace Journalist
George Gaynes
Mission Director
Tom Stewart
Houston Cap Com
Duke Hobbie
Air Force Titan Specialist
Walter Brooke
Network Commentator
Dennis Robertson
Launch Director
Kenner G. Kemp
Guest in Observation Room (uncredited)