Jupiter 2 was a starship designed and constructed by the United Global Space Force. The ship was engineered to transport a single family - the Robinson Family - in cryosleep to the planet Alpha Prime in the star system Alpha Centauri (though this is not stated in the movie). Their mission would be to travel at slower-than-light speed to Alpha Prime, and once they reached their destination they were to begin construction of a second Hypergate in orbit around their destination planet. Their mission was timed as such that by the time they had reached Alpha Prime, the first Hypergate orbiting Earth would be completed and the two gates would then be connected via hyperspace so as to allow the human species to journey to another planet capable of sustaining life and escape the dying Earth.
The Jupiter consisted of an outer launch capsule, the Jupiter 1, and an interstellar starship, the Jupiter 2, equipped with a hydroponics bay, medical bay, and an experimental hyperdrive. The hyperdrive was meant to be used only when the construction of the Hypergates had been completed, otherwise the ship's escape vector would be random. The Jupiter 1 would first lift off via conventional propulsion into orbit from atop a launch tower and, once above the Earth, it would break apart explosively. The Jupiter 2 starship would then ignite its engines and begin its ten year mission to Alpha Prime.
However, the mission was jeopardized when a lone rogue spy for the Global Sedition Force sneaked aboard ship. Dr. Zachary Smith was hired to sabotage the whole operation and thereby prevent the Robinson Family from reaching their destination. He reprogrammed the Robinson's construction robot to destroy all operating systems aboard ship, ensuring they would never reach their destination. However, Dr. Smith was betrayed by the Sedition and ended up being knocked out via an electric pulse before the launch of the Jupiter. When in space, the robot awakened and began carrying out Smith's new program, causing damage using its pulse lasers and creating havoc. Smith awakened the Robinsons, and Will was able to shut down the Robot before it could cause any further damage. However, the resulting damage to the ship's navigation system caused it to veer off course severely. The Jupiter 2 was drawn toward the sun, threatening the family, their pilot, and the stowaway. Before the ship could plummet into the sun and be destroyed, Major West persuaded Professor Robinson to use the ship's experimental hyperdrive to propel the ship through the sun itself and away from danger. Robinson hesitated, but ultimately made the call to activate the hyperdrive and escape certain death. Unfortunately, due to a lack of destination gate, the hyperdrive's exit vector was random and the Jupiter 2 leaped into uncharted space.
Despite its size and mass, the Jupiter 2 was capable of landing and taking off from planets using a levitation field and its rockets, and had several landing legs that could support its weight upon landing. It carried a Space Pod and Chariot, though upon landing at their first alien world they were both deemed a total loss. The ship was armed with a torpedo launcher capable of launching flak burst torpedoes which could be configured to create shapes out of their shrapnel, as when Major West created the shape of the Jupiter mission crest in the sky to allow the Robinsons to find their way back to the ship. Also onboard were several long range pods, seen in "The Passengers", a spinoff novel.
This Jupiter 2 is very different from the original ship in every measurable way, from the slick organic shapes to the fact that it had an obvious bank of rocket engines. In most cases, the original interpretation is considered canon by fans.
