Lost in Space is a science fiction TV series created and produced by Irwin Allen, filmed by 20th Century Fox Television, and broadcast on CBS. The show ran for three seasons, with 83 episodes airing between September 15, 1965, and March 6, 1968. The first TV season was filmed in black and white, but the remainder were filmed in color. In 1998, a Lost in Space movie, based on the TV series, was released.

Though the original TV series concept centered on the Robinson family, many later story lines focused primarily on Dr. Zachary Smith, played by Jonathan Harris. Originally written as an utterly evil but extremely competent would-be saboteur, Smith gradually becomes the troublesome, self-centered, incompetent foil who provides the comic relief for the show and causes most of the episodic conflict and misadventures. Smith was not in the un-aired pilot and neither was the robot. A meteor storm in the un-aired pilot put them off course. In the first aired episode, Smith's sabotage and unintended presence caused them to go off course so that they encountered the meteors. In the un-aired version, they were going at such a relatively slow speed that they wondered if they were on Mars, while in the first aired episode, just seconds of hyper-drive and they were lost, unknown light years from Earth.