Ms. Frizzle's class is learning about the Solar System and Arnold's unpleasant cousin Janet, who constantly raves about herself, has joined them.

However, on the way back to school, Ms. Frizzle pushes a button that makes the bus transform into a rocket and blast off into outer space.

Janet looks through the Friz's things and finds Ms. Frizzle's lesson book, which documents the information she is supposed to tell the kids during the field trip (complete with "Arnold, are you listening?"

Janet then flips through the book and finds the instructions for the autopilot, so they can fly back to the asteroid belt and rescue Ms. Frizzle.

Michele Landsberg of Entertainment Weekly gave a very positive review of the book, saying that, "The fun is irresistible and the information substantial [...]".

The episode is infamous for its third act in which it unintentionally teaches that one could survive without a helmet in the vacuum of space if brought back into an oxygen-filled environment quickly enough.

Also, instead of remaining in the asteroid belt, Ms. Frizzle uses her jet pack to fly off to another planet and provides the kids with clues as to her location via the radio on the bus.

Arnold (in protest against her desire for proof) demonstrates to Janet what would happen to her if she remains on Pluto by removing his space helmet.

Despite the producer segment indicating otherwise, it is not implausible that Arnold could survive exposure to the thin atmosphere of Pluto after removing his helmet for long enough to be rescued.

The common cold is a viral infectious disease and one particularly could not catch it in the virtually airless atmosphere of Pluto as Arnold does in the episode.