Guided by a catalog of planets found aboard an alien spaceship, the Robinsons have located a marginally habitable planet nearby where they can put down for major repairs that can only be undertaken under gravity.

Unwilling to land before investigating conditions on the planet, John decides to make the descent using parajets, arm-mounted rockets that will take him safely down to the planet's surface for exploration. When he is nearing the planet, John's parajets begin to malfunction and all communication with the Jupiter 2 is lost. Smith seizes the opportunity to employ The Robot to force Don and Maureen to abandon John and return the ship to Earth immediately. Seemingly complying with Smith's order, Don suddenly throws the ship into a violent manoeuvre that allows him to restrain Smith long enough to force him to order the Robot to leave the control deck. After placing Dr. Smith in suspended animation, Don and Maureen take the ship down to the planet.

The Jupiter 2 crashes on the planet due to an earlier act of sabotage by Dr. Smith of the ship's rockets. The Robot is sent out to analyze the environment before anyone is allowed to leave the ship to look for John. Although only marginally habitable, the planet will sustain life. The Robinsons soon assemble the chariot and begin to search for John.

As they search, they come across a small ape-like creature. Penny impetuously asks if she may keep it, but her mother angrily refuses, preoccupied with finding her husband. When she realizes the devastating effects of her words, though, she relents, and Penny names the creature Debbie. Back at the ship, the Robot frees Dr. Smith from suspended animation, having been programmed to monitor his well-being at hourly intervals. The search party eventually find John trapped in a chasm, tormented by electrical discharges that have rendered him almost completely helpless and destroyed his radio.

Upon reaching the Jupiter 2, they are shocked to find Dr. Smith revived; they seem to expect a confrontation, but Dr. Smith is strangely conciliatory and apologetic. Soon after, Dr. Smith issues new orders to the Robot. It is to eliminate all members of the party except Major West, who will be needed to pilot the ship. The Robot is to use every opportunity to find the individual Robinsons alone and kill them with no witnesses so that their deaths may be attributed to adverse reactions to unknown elements in the planet's atmosphere.

Against his father's orders Will goes to the chariot that night to make repairs. While Will is at work, the Robot follows him to carry out Dr. Smith's order. Ignoring Will's orders to stop, it continues to approach him while discharging powerful electrical bolts from its claws.

Some notes on scientific accuracyEdit

In the first episode of Lost in Space, we are told that the Jupiter 2 will take five and a half years to reach our sun's nearest stellar neighbors in the Alpha Centauri system. The Robinsons are to be placed into a state of suspended animation for the duration of this lengthy voyage. Now, just two episodes later, without any more time spent in suspended animation, the Jupiter 2 has reached a habitable Earthlike planet orbiting another star. Since the Alpha Centauri system (which actually consists of three stars- Alpha Centauri A and B, and Proxima Centauri) is the closest other star system to Earth, the Robinson's planet must be even further away. How did they get there so quickly? The Jupiter 2 is said to have traveled in hyperspace beyond the speed of light. In narration, professor Robinson tells us that travel in hyperspace could have propelled the ship anywhere in our galaxy. In reality, physicists studying Einstein's general theory of relativity have identified exotic methods of faster than light travel, including wormholes and space warps. However, such methods would require truely immense quantities of energy, and it's hard to see how the Jupiter could have acquired such an ability by accident through damage to its navigation system. It's like supposing that smashing the GPS system in your car would suddenly cause it to develop the ability to make a suborbital flight to Europe.

The other main item for comment in this episode are the parajets, small wrist mounted rockets that supposedly brake John Robinson from orbital speed and allowed him to fly over a planetary surface. Special effects being what they were at the time, we don't actually get to see this. When John is near the surface we just hear his voice on the radio. It's a good thing, because it's really hard to imagine someone flying with rockets mounted on their wrists. I don't even much need to remark on the lack of room for the needed fuel for this device. Real jetpacks developed in the '60's could only fly a few minutes due to fuel limitations and they had big fuel tanks on the wearers back. John also had no heat shield to protect himself from the heating due to atmospheric friction when entering a planetary atmosphere. As wild as it sounds, NASA actually did develop an orbital bailout scheme that would have allowed a real astronaut to do something like what John Robinson did in this episode. It was called MOOSE (Manned Orbital Operations Safety Equipment) and was small enough to fit into a suitcase. It consisted of a rocket motor to de-orbit the astronaut and an inflatable shelter to be filled with polyurethane foam. The shelter served as a heat shield during atmospheric reentry and as a cushion on landing. A parachute, radio transmitter, and survival kit completed the device. Of course, it wouldn't have provided something that John Robinson needed: a way to return to the Jupiter 2 in orbit. The parajets were supposed to do that too. Yeah, sure... and there are hillbillies, circus masters, and department store clerks out in space too. Another grounds for comment are Don West's and the others conduct around Debbie the bloop. Approaching and picking up a wild animal, even here on Earth, would be a foolhardy thing to do. Approaching an unknown alien wild animal on another planet and picking it up is beyond stupidity. This would be a great way to discover how alien wild animals protect themselves from predators.

Background InformationEdit

  • This episode begins a multi-episode arc with the Robinsons, for now, stranded on this new planet.
  • This is the first time the chariot is used. Don makes specific reference to assembling the vehicle, which is implied to be a one-person job, though Will assists.
  • Besides his talents as a screenwriter, Norman Lessing was also an expert chess player and was acknowledged as same by the United States Chess Federation; thus, having characters here playing chess is not surprising.
  • The writer co-credits were probably due to a rewrite of Shimon Wincelberg's orignal work to accommodate the inclusion of Dr. Smith.  Wincelberg is listed as a writer on many early scripts  and worked with Irwin Allen on the original premise of the show when it had neither Smith or the Robot.  As the first episodes include much of the original pilot's footage, chances are Allen paid other writers to add scenes that would enable him to use the footage in an episode that was consistent with the revised format.
  • Smith refers to the "green hills of earth", the title of a short story by Robert Heinlein.
  • This marks the only time in the series that the Robinsons' EVA 'Parajets' were used. The third season's space pod makes the Parajets obsolete. As the Pod was not added to the props until the third season, it was not available for use by Professor Robinson in this episode. In-universe, the clear dangers demonstrated by the parajets' use provide a sound reason for them not being used again. However, if this equipment was available, and was advanced enough to allow a human to not only do an EVA but land safely on a planet, why weren't they used by John in "The Reluctant Stowaway" when he did his EVA or utilized to rescue him when his line broke?
  • For the last time, the freezing tubes of the Jupiter 2 are used. And they are used for two unusual reasons: to incarcerate Smith (briefly) and to protect Don during the crash landing.
  • Also this marks the last time Smith is called by his title of Colonel by any character, soon he would be just Doctor.
  • Don places himself in a freezing tube as protection during the crash instead of joining the others. This was done so the shot showing the crash landing from the Flight Deck POV in "No Place to Hide" could be used here.
  • Strange science - arm thrusters and an unprotected astronaut surviving a brush with a planet's atmosphere. John managed to get the parajets working - and far enough from the surface to survive a landing - when they were supposedly out of fuel in the first place.
  • The idea of an astronaut jumping from high altitude to land safety on a planet's surface had been explored by NASA under Project Excelsior. Instead of parajets the astronaut was to use a drogue parachute, the type used by drag racers to stop themselves. And in March 2012 adventurer Felix Baumgartner jumped from a height of 13.5 miles and landed safely; he plans a future jump from 23 miles up.
  • Professor Robinson says, he doesn't get the parajets to working until 100 feet above the ground, at assuming 32ft/s/s for a planet equal to the "earth's mass" Don's going to need less rope and more glad bags to get Professor Robinson out of that hole. That said, what John experiences is similar to a HALO parachute jump (high altitude, low opening) - except HALO jumpers don't parachute in from orbit.
  • The strange bush that saps the Chariot's power is referred to as an 'Electric Sagebush' in the the title theme that plays over its scene. How come we never ever see the Electric Sagebrush ever again? Is it the only one? (odd). The way the scene is edited renders it unclear as to whether it's a bush or an attacking creature.
  • When Professor Robinson is using the rope to climb out of the gulley, you can see that the Silver coating on his spacesuit costume has worn off in the seat of his pants.
  • If Will can fake Smith’s voice, why doesn’t he order Robot to take orders from everyone? Or better yet, from everyone EXCEPT Smith?
  • Why does John talk so loud when giving the Robot orders? He’s mechanical, not deaf!
  • Why does the Robot pull Colonel Smith out of the freezing tube? Technically he’s in perfect health and uninjured. So isn’t he perfectly “safe” in there?
  • Later in the series, viewers discovered that the name of the planet is Priplanus. It is constantly misspelled such as: Preplanis, Preplanes, Priplanis, Preplanis, Preplanas, and many other misspellings.
  • It is the Gemini XII miniature that is shown crash landing on the planet. In some shots you can see the larger front window, and the flatter lower section. Two wires are used to suspend the model as it flies over Red Rock Canyon.
  • There is what appears to be two pieces of note paper inside the Robot's collar. They can be seen throughout the entire episode.
  • Just after Don puts Dr Smith in the freezing tube we see two external shots of the space ship rocking and rolling significantly but Don and Maureen inside the spaceship remain upright. When the spaceship is rolling and then re-aligning itself after Don yells "Maureen, the stabilizers!" you can see the stars right through the edges of the vessel. It appears transparent and totally animated. This is because the miniature was suspended vertically on two guide wires, but the footage is shot using a blue screen. Because of the angle of the lighting, a shadow is caused when the miniature was tilted to one side. This causes the image of the miniature to blend in to the blue screen star field.
  • When Don is about to leave the air lock of the ship to join everyone in the Chariot to search for John, it looks like he has placed a small note paper on the inner hatch window. Later when the Robot returns to free Dr Smith from the freezing tube, the paper has disappeared.
  • There is a noticeable dent in the front of the chariot, just below and in the middle of the front window. It can be seen just as the vehicle pulls up and later finds the Bloop and John. [Don’s only been driving for 5 minutes and he’s already had his first smash!]
  • Dr Smith is able to touch the Robot’s claw without any effect, only seconds after the automaton discharges his electrical bolts to demonstrate that its electrical defences are active.
  • When the Robinsons return to the Jupiter 2, Maureen says to the girls, "Let’s get dinner started" and instead of entering the Jupiter 2, she and the girls walk off to the right of the ship. What are they going to do? Collect firewood? The same thing happens to Will after he argues unsuccessfully with his father to fix the Chariot. [maybe that’s where the lunch wagon is…]
  • The bloop, a.k.a. Debbie, joins the show; she is obviously a chimpanzee wearing fake ears. Considering she's the first friendly alien encountered by the Robinsons, Penny and her mother take great liberty in assuming Debbie is available for adoption as a pet.

Next episode: There Were Giants in the Earth

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