starship alpha

With past talk about rocket boot, 'Bot and vorpal blade; it remind me of another role-playing game that came out about the same time as AD&D: Starship Alpha (I think it called...something like that).
The whole story-line: Starship Alpha was a gigantic ship, 50 mile long and 10 mile wide, 5 cylindrical level (50 mile long) with radius's 5 mile/4 mile/3 mile/2 mile wide (fifth level 1/4 mile wide or so...use for ship storage and lift/elevator). Each of the level was tropic (5 mile wide), subtropic and desert (4mile wide), temperate (3mile) and subtemparate or tundra (2mile),like climbing up a moutain. Each level was an "Ark" with animal and plant life...and (subtropic) a city with human colonist. Within each level are storerooms with all of the want and need that the colonist could ask for (there no going back to earth). Whatever happen to Starship Alpha on maided voyage toward new planet and new home.....it suffer a space tragedy!
It came across Blackhole/radiation/spacial enigna/(etc) that mutated and killed many of the crew, colonist, plant and animal. With radiation affect the city (say) the survivors must put the Starship on automatic and situp shop in the (temperate) level wild....time go on...
The role-playing scene opens with the players characters("Crue"-Rogue, "soltat"-fightman,"techno"-psionic wizard,"Doc"-psionic cleric and "Echo"-psionic Druid), arm with clubs and swords make with mutant "Ironwood" must explore, face mutant creature and "cultist" Echo, on each level.
Long time had pass, when they have explore and conquor each level, within each level and the front (command & control) and the Starship engineroom, they make a stunning discovery---the starship is orbiting around their new planet/new home (???Faerun???).