Assembly and Fueling Facility (MZK)

The Assembly and Fueling Facility (11P593) was a building specifically constructed for the Energiya-Buran program. Height has been given between 70 and 80 m, length between 110 and 150 m, and width between 70 and 80 m. Contrary to what the name suggests, it was not really used for assembly work, but primarily for hazardous operations with the entire Energiya-Buran stack or Buran alone. The facility was built around a metal frame designed to withstand possible explosions during such operations. It has no equivalent at the Kennedy Space Center, being used for tasks that NASA performs either out on the pad or in the Orbiter Processing Facility.

The Energiya-Buran stack passed through the MZK before being rolled out to the pad for final launch preparations. Among the activities carried out with the orbiter in this building prior to flight were:

– loading the propulsion system tanks with kerosene;

– loading the Auxiliary Power Units with hydrazine and nitrogen gas;

– loading ammonia into the thermal control system;

– loading of nitrogen into the tanks of the Fire Protection System;

– filling the Pressurization and Depressurization System with air;

– installation of storage batteries and fuel cells;

– installation of cargo into Buran’s payload bay.

Another operation conducted at the MZK was the installation of pyrotechnic devices for the separation of the strap-on boosters and Buran from the core stage.

The MZK was also the first facility to receive Buran after landing for removal of any residual fuel and gas, for removal of storage batteries and fuel cells, unloading of cargo from the payload bay, and removal of flight recorders. Residual LOX for the ODU propulsion system and residual LOX and liquid hydrogen for the fuel cells were removed on a special platform near the runway, but residual kerosene in the ODU system and hydrazine for the Auxiliary Power Units were removed in the MZK.

Buran was also delivered to the MZK prior to and after test firings of the propulsion system engines and Auxiliary Power Units on the test-firing platform on Site 254. In the MZK the vehicle was equipped with a special support unit to enable ODU test firings and loaded with hydrazine for test firings of the Auxiliary Power System.

The MZK was also the facility where the Polyus spacecraft, the payload for the first Energiya mission in 1987, was mated with the launch vehicle. It is not clear, however, if future payloads other than Buran would also have been integrated with the launch vehicle in this facility [12].