15 episode serial where Jack Armstrong, the All-American Boy, battles the evil Dr. Grood, who has placed a death ray aboard his spaceship orbiting Earth.
| Actor | Role |
|---|---|
 John HartJack Armstrong | Jack Armstrong |
 Rosemary La PlancheBetty Fairfield | Betty Fairfield |
 Claire JamesPrincess Alura [Chs. 3-6, 9-11, 15] | Princess Alura [Chs. 3-6, 9-11, 15] |
 Joe Brown Jr.Billy Fairfield (as Joe Brown) | Billy Fairfield (as Joe Brown) |
 Pierre WatkinUncle Jim Fairfield | Uncle Jim Fairfield |
 Wheeler OakmanProf. Hobart Zorn | Prof. Hobart Zorn |
 Jack IngramHenchman Blair | Henchman Blair |
 Eddie ParkerHenchman Slade | Henchman Slade |
 Hugh ProsserVic Hardy | Vic Hardy |