Over the first two seasons of Lost in Space and the first episode of season three, the Robinsons stood on four different planets: the Earth, Priplanus, the Automated Planet, and the Sector 6:30 Planet. Viewers see their launch from Earth (“The Reluctant Stowaway”), their crash landing on Priplanus (“Island in the Sky”), their take off from there (“Blast Off into Space”), their arrival and departure from the Automated Planet (“The Ghost Planet”), their landing on the Sector 6:30 Planet (“The Forbidden World”), and their departure from there (“Condemned of Space”). All of this is very cut and dried; there is no room for confusion—every step of their journey is seen on the television screen.
With the rest of season three, however, continuity becomes a major issue. Now there is continuity and continuity. Most fans have probably noticed any number of continuity issues in the series. These might be real, with one episode ending with almost enough fuel for take-off, and the next beginning with the Robinsons having nowhere near enough deutronium. Other continuity issues might be called implied; for example, in an earlier episode the Robinsons are in trouble because some key piece of equipment has broken down and they have no spare part, but in the season two episode “The Space Vikings” we are introduced to the Robot’s replicator add-on and ask why the crew didn’t just use that to manufacture the spare part they needed earlier.
A completely different problem in continuity arises from not portraying or even referring to landings and take-offs that are logically required by the settings of the different episodes. Accepting the original broadcast dates as giving the definitive order of the Robinsons’ adventures, we see them arrive on a good number of the planets they visit, but only leave a handful of them. This begins to present problems mid-way through season three (we have reason to believe that earlier episodes in this season were broadcast out of production order, in itself not uncommon, with the specific goal of providing continuity).
In the 70th episode broadcast, “Deadliest of the Species,” the Jupiter arrives on an unnamed planet, on which they remain for the next four episodes for want of any evidence to the contrary; they are never shown actually taking off from this planet, though.
Episode 75, “Target: Earth,” begins with the Robinsons in outer space. At the end of the episode, their intention to depart is clear, but not shown. This episode is then followed by two which take place on a planet (presumably the same planet in both episodes, “Princess of Space” and “The Time Merchant”), but Jupiter 2 is not seen to arrive on the planet nor to depart from it. The next three episodes broadcast (“The Promised Planet,” “Fugitives in Space,” and “Space Beauty”) follow the same pattern, with no connecting take-offs and landings.
“The Flaming Planet” (episode 81) begins in outer space and ends on the planet of the Sobrams. The Jupiter 2 does not actually land, but several crew members go down to the planet in the space pod. In the final two episodes shown, “The Great Vegetable Rebellion” and “Junkyard of Space,” the Robinsons start in outer space, land, but never take off.
So how much do these lapses in continuity affect the overall perception of the show? Not much, by a long chalk. Continuity in any form was not a strong point of the series to begin with, so at most it is just a bit disconcerting to the Type A’s among us who watch the episodes in order. But I have to ask (tongue in cheek, obviously) why Irwin Allen never thought of reusing a few seconds of landing or take-off footage from an earlier episode just as an establishing shot? Other producers reused footage, props, and story lines over and over again; why not Allen?