PREPARING FOR THE MISSION First orbiter roll-outs

After the Energiya pad fueling tests and core stage test firings in 1985-1986, the focus shifted to pad tests of the entire Energiya-Buran system. For this purpose the Russians used two full-scale mock-ups of Buran called OK-ML1 and OK-MT, delivered to the cosmodrome by VM-T carrier aircraft in December 1983 and August 1984. The work began in January-February 1986 when OK-ML1 was mated with the 4M core stage (a stack known as 4MP1) for a series of tests at the Assembly and Fueling Facility (MZK). Several weeks later 4M was united with OK-MT (a stack called 4MP or 11F36P) for more tests at the MZK from 13 to 16 May.

After roll-back to the Energiya assembly building, 4M was reconfigured for a series of fueling and dynamic tests with the OK-ML1 vehicle on both the UKSS and Energiya-Buran pad 37. Both the core stage and strap-on boosters were loaded with simulated propellants. The dynamic tests were necessary because the huge Dynamic Test Stand was still under construction and saw the use of small solid-fuel rockets on the core stage to create vibrations. Dubbed 4MKS-D, the stack spent two weeks on the UKSS (13-28 August 1986) and over a month on pad 37 (29 August-4 October 1986) [35]. This was the first time ever that an Energiya-Buran combination had spent time on the pad.

Next up was the 4MP/11F36P stack with the OK-MT vehicle for various loading tests of the orbiter both in the MZK and on launch pad 37. The combination was

rolled out to the pad on 5 May 1987 and shown to General Secretary Gorbachov during his visit to the cosmodrome in mid-May. 4MP returned to the MZK on 14 May, one day prior to the launch of Energiya 6SL, to make sure that it wouldn’t be damaged in case the Energiya blew up during lift-off. Afterwards, it spent one more month on the pad (28 May-29 June 1987) to complete the tests. Similar tests with the 4MP stack were conducted on pad 37 in October-November 1987. After that, the flight hardware for the first Energiya-Buran mission was ready to make its appearance on the pad.