The Jupiter II class spaceship was a 6 man vessel built to transport colonists to nearby star systems such as Alpha Centauri. Its design borrowed heavily from the earlier Jupiter I but by making use of the new quantum contradimensional deck compression technology the Jupiter II was able to squeeze 2 levels into the 6' tapered space below the flight deck. The galley, dormitory and ablutions were moved down to the new living deck, freeing 3 bays on the flight deck that could now accomodate a lift down to the lower decks and 2 more banks of freezing tubes making 6 tubes in all, enough for a family. Below the living deck the service deck contained the reactor chamber, exit corridor and landing gear.
Space was also found to accomodate a launch bay for an exploration pod capable of scouting planets from orbit, a garage for a chariot that could be deployed down a ramp upon landing and a station for one of the newly developed (if somewhat twitchy) B9 environmental control robots. The living deck also included an observatory and laboratory.
The gravimetric drive was upgraded to achieve near lightspeed, bringing journey times to local star systems down to a few years. Too late it was discovered that the new design when exposed to deck compression was prone to the Allen-Kinoshita gravimetric malfunction effect, whereby sudden loss of cabin pressure could, surprisingly, cause the engine to enter a "hyperdrive", propelling the entire ship in a random direction at many times the speed of light. The first-in-its-class Jupiter II was launched in 1997 and it is believed that just such a malfunction could have been responsible for the Robinson family and their pilot Major Don West all getting hopelessly...
LOST IN SPACE!!!!!!
The exterior profile is based on the sleek hero miniature with an outer diameter of 49 feet, resulting in a total height, landing gear retracted, of 17 feet. This is slightly larger than the main studio set at 43.5 feet seen in every episode, or the huge 40 foot diameter Jupiter II prop on legs first seen in S1E02 "The Derelict".
The interior decks are based on the main studio sets and their original blueprints where I could find these online, and I watched the first five episodes a lot, which was fun because they're the best. Hence the muted colour scheme. I like silver.
My version most resembles the first season Jupiter II except where I really liked the look of a later season feature or my inner engineer took over. The Jupiter II was protean, its layout and instrument banks changing form and function between seasons, episodes and sometimes even scenes. Part way through the 3rd season a little used door on the flight deck was revealed to lead to a small hanger for deploying a landing pod, never mentioned before during 61 previous episodes.
The original un-aired pilot (rushed out by Allen to sell the show to the networks) had a blank cockpit but in the improved broadcast pilot it was revealed that a pilot's chair folded out plus two instrument panels. A second pilot chair was added in the second season so that John and Don could sit together and the old chair hole was filled with a new instrument panel featuring a jazzy Moiree fringe radar display, meaning the folding chairs had nowhere to stow. As an engineer this annoyed me, hence my own cockpit design, never seen in the show.
Some might argue with the garage on the grounds that the chariot is stowed disassembled, but on the original plans for the 40 foot Jupiter II prop Irwin Allen had included an actual working ramp down which the chariot could have been seen exiting the saucer, but it was never built in. The corridor I have leading to it from the lower deck was a part of the actual set and can be glimpsed in some scenes.
The part of the ablutions segment containing the ultrasonic laundry and hand basin was built and is sometimes visible between the bedrooms. The toilet and shower are on the original plans behind a folding door but were not added to the set. Maybe they were for the Italian version.
The power core and its approach corridor is based mainly on S3E10 "The Space Creature" with the spherical reactor chamber from S1E12 "The Raft" plus some Taurean/Seaview detail I liked.
I considered extending the lift down to the service deck so that the robot could get out (like it is seen doing in S2E03 "The Ghost Planet") but then I reckoned it would still never get down the steps so why bother? It can use the chariot ramp.
There is no cut-away view because contradimensional compression distorts the cross-sectional perspective such that all who behold it go insane, something I learned the hard way. Wibble.