Peter Dyneley
Jeff Tracy (voice)
Shane Rimmer
Scott Tracy (voice)
Jeremy Wilkin
Virgil Tracy / Power / DJ Tom (voice)
Matt Zimmerman
Alan Tracy (voice)
David Graham
John Tracy / Brains / Loman / Sentinel Base Computer (voice)
Ray Barrett
Rick O'Shea (voice)
Sylvia Anderson
Professor Mitchell (voice)
Christine Finn
Tin-Tin Kyrano / Grandma Tracy (voice)
Charles Tingwell
International Space Control (voice) (uncredited)