Scott Tracy (voice)

Virgil Tracy (voice)

Alan Tracy (voice)

Gordon Tracy / Brains / Morrison / Bob Gray / Solarnaut Asher / Captain Hanson / Frank / Dave Clayton (voice)

Eddie Houseman / J.B. Lester / Colonel Harris / Fireflash Co-Pilot / Assistant Controller / Bridge Controller (voice)

Chip Morrison / Lady Penelope Creighton-Ward (voice)

Tin-Tin Kyrano (voice)

Solarnaut Camp (voice) (uncredited)