In order to allow for exploration or repositioning of the base, the habitation modules may have been installed on wheel chassis, and multiple docked to form a movable train.
The moonbase project was ordered by the Soviet space chief Korolyov to Vladimir Barmin's Spetcmash bureau.
The modules were to be 4.5 meters in initial length, and grow to full size by an expanded mechanism and air compression after delivery.
[clarification needed] The train had a manipulator arm which would have enabled the collection of samples of soil without the use of space suits.
The realization of the project depended on key parts of the N1-L3 program - the N-1 superheavy launcher, all 4 launches of which failed between 1969 and 1972.
[6] All crewed Soviet lunar programs, including a Zvezda moonbase, had been classified as top secret and were only published in the glasnost epoch since 1990.