While on a field trip to MASA, Commander Cone gives Mikey and Bunsen a tour of MASA and accidentally launches them into space.
- Jeremy Rowley as Bunsen
- Ben Giroux as Mikey Munroe
- Kari Wahlgren as Amanda Killman, Sophie Sanders
- Jerry Trainor as Commander Cone
- Cheri Oteri as Miss Flap
- Jeff Bennett as General Lance Justice
- The episode's title is a pun on astronauts.
- This is the third half-hour episode of the series.
- MASA is Muckledunk's low rent and off-brand version of NASA.
- In this case, MASA stands for Muckledunk Aeronautics Space Administration.
- There is an episode of Timon & Pumbaa that used the same title.
- "Astro-Nots" was released on Nick.com a day before its broadcast.
- When General Lance gave a book to Bunsen about the MASA Alien Shield Program, the picture on it is a reference to the 1978 arcade game Space Invaders.