In the year 1997 the Robinson family take off to colonize Alpha Centauri. A spy from a foreign country AKA Dr. Smith becomes trapped aboard trying to sabotage the project. The ship is whisked off course and into a meteor storm due to Dr. Smith's extra weight upsetting the navigational computers. Smith desperately tries to save himself by reviving the crew. The result: the Robinson family becomes lost in space.

Professor Robinson attempts to explore a planet that the Robinson's are planning to land on. His para-jet propulsion system fails due to sabotage by Dr. Smith. Major West "lands" the Jupiter II, in spite of the fact that Dr. Smith has also sabotaged the propulsion system of the Jupiter II, and the family and Major West rescue Professor Robinson.