The Time Machine (episode)

Episode 27 of the 1980 TV series

Plot
A time traveler named Rock comes and takes Astro along with Black Jack to help a princess (Sapphire) in the past.

Trivia

 * This episode contains elements from the Tezuka movie, Undersea Super Train: Marine Express.
 * When Rock and Black Jack are talking about Science Fiction, Darth Vader from the Star Wars franchise makes an surprise cameo.