Cliff Robertson

as Col. Edwin A. 'Buzz' Aldrin Jr.

Shirley Knight

as Joan Aldrin

Charles Cioffi

as Dr. Sam Mayhill

Ralph Bellamy

as Col. Edwin E. Aldrin

Stefanie Powers

as Marianne

Kraig Metzinger

as Andy Aldrin

Tony Marks

as Mike Aldrin

Stephen Pearlman

as Dr. Hotfield