Walter Cunningham (Himself - Astronaut), Buzz Aldrin (Himself - Astronaut), Jonathan Young (Himself), William Henry (Himself - Author), Giorgio A. Tsoukalos (Himself), Rick Stroud (Himself - Author), John Brandenburg (Himself - Plasma Physicist), Paul Davies (Himself - Astrobiologist), Michael Salla (Himself), David Childress (Himself)