37K-Mir Credit: Mark Wade. 19,067 bytes. 640 x 217 pixels.

Development of a new kind of Soviet space station module, designated 37K, was authorised on 17 September 1979. The basic 37K design consisted of a 4.2 m diameter pressurised cylinder with a docking port at the forward end. It was not equipped with its own propulsion system. The original authorisation was for a total of eight 37K's of two configurations: 37KS for use as space station modules for Mir, and 37KB for use with the Buran space shuttle. Design and fabrication reached an advanced phase when it was decided that the separate tug concept resulted in too low a net scientific payload (3 tonnes). Integrating the tug with the module was expected to increase this to 5 tonnes and provide some reserve engine capability at Mir and additional pressurised volume. Accordingly the 37KS modules for Mir were cancelled in 1983. Competitive designs for integrated space station modules were submitted by KB Salyut and NPO Energia. The KB Salyut 77K modules were derived from the cancelled TKS manned ferry. The competing proposal from NPO Energia combined the 37KS module with the engine unit of Mir. In June 1984 the KB Salyut design was selected.

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37K Comparison Credit: Mark Wade. 22,590 bytes. 264 x 480 pixels.

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Maximum Diameter: 4.2 m. Total Mass: 20,000 kg. Total Payload: 5,000 kg. Main Engine Propellants: N2O4/UDMH. Main Engine Isp: 305 sec.

The basic 37K design consisted of a 4.2 m diameter pressurised cylinder with a docking port at the forward end. It was not equipped with its own propulsion system. The original authorisation was for a total of eight 37K's of various configurations. Of these, only the 37K-E (Kvant module of Mir) and the 37KS (instrumentation module in Buran) would fly.