The Universal Test Stand and Launch Pad (UKSS)

One of the lessons learned from the ill-fated N-1 program was the need to build a test stand for full-scale test firings of the Energiya’s rocket stages. The site selected for the test stand was situated several kilometers to the northwest of the Raskat complex, where any explosions would not damage buildings in the Technical Zone. The test stand was designed to support both individual as well as joint test firings of the core stage and strap-on boosters. The opportunity to test the rocket’s engines in actual flight configuration minimized the risk of catastrophic launch failures and was one of the reasons the Energiya-Buran pads remained relatively close to the Technical Zone.

Designed to withstand the pressure of an Energiya rocket bolted to the pad and producing 3,600 tons of thrust for dozens of seconds, the test stand could also be easily converted into a launch pad for Energiya rockets with payloads other than Buran and also for the massive Vulkan rocket, an Energiya with eight strap-on

boosters. It therefore became known as the Universal Test Stand and Launch Pad (UKSS or 17P31).

The UKSS had one fixed service tower, almost identical to the “fueling tower” of the Energiya-Buran pads. It also featured an equally high mobile tower that provided access to virtually every part of the rocket and was equipped with a crane for hoisting operations. The UKSS had one enormous flame trench with a depth of 40 m that could easily be seen on satellite photographs of the cosmodrome. Being exposed to much higher temperatures and acoustic pressures than the Raskat pads, the UKSS had a much more elaborate sound suppression water system, consisting of three reservoirs containing a total of 18,000 m3 of water which was sprayed onto the pad at a maximum rate of 18 m3 per second. The UKSS was surrounded by two lightning protection towers and several floodlight towers. A special propellant storage complex was built several kilometers from the pad. Several support facilities for the UKSS were located at the neighboring Site 250A. The most important of these was a control center some 3 km from the test stand which was designed to withstand an on-the-pad explosion.

The groundbreaking ceremony for the UKSS was held on 20 August 1978. The stand was supposed to have been ready for the first test firings in 1982, but construc­tion ran into serious delays. Initially, the prime contractor for the construction of the facility was NIIKhimmash, which operated several rocket engine test stands at a site north of Moscow not far from Zagorsk. However, because it was of the utmost importance to have the test stand ready before the Energiya-Buran pads, it was decided early on to assign the task to the leading launch pad design bureau KBOM, while NHkhimmash remained in charge of the actual test-firing program.

The first roll-out of an Energiya mock-up to the UKSS took place in early 1983. The pad was used for a series of core stage fueling tests with the Energiya 4M vehicle in 1985. Original plans for individual and joint test firings of the core stage and the strap-on boosters were severely curtailed. In 1986 the UKSS witnessed two test firings of the core stage of the Energiya 5S vehicle. These test firings were to continue with Energiya 6S, but in 1985 a decision was made to turn that vehicle into a flightworthy rocket (redesignated 6SL) and fly it with a payload called Polyus. As a result, the UKSS was converted into a launch pad much earlier than planned. The launch of Energiya 6SL took place on 15 May 1987 and, although the rocket operated flaw­lessly, the payload was not inserted into orbit due to a navigation error. The pad itself was seriously damaged because the sound suppression water system failed to operate (see Chapter 6) [15].