Miles' eagerness to go Astro-caving with Uncle Joe and the Cosmic Explorers makes him overlook his preparations.
- Justin Felbinger as Miles Callisto
- Sam Lavagnino as Blodger Blopp
- Fiona Bishop as Loretta Callisto
- Olivia Munn as Phoebe Callisto
- Tom Kenny as Leo Callisto
- Dee Bradley Baker as M.E.R.C.
- Issac Brown as Haruna Kitumba
- Adrian Grenier as Captain Joe