OK-GLI

Airframe no.: 0.02

Energia designation: 2M

Alternative designations: OK-ML2, OK-ML2-GLI, OK-GLI, BTS-002, BTS-02

BTS-02 — Bolshaya Transportnaya Sistema-02 (Large Transport System-02)

OK-GLI — Orbitalnyy Korabl (dlya) Gorizontalnykh Lotnykh Ispytaniy (Orbital Ship [for] Horizontal Flight Tests)

Buran aerodynamic analogue, used between 29.12.1984 and 06.12.1990 for piloted atmospheric tests. Over 11 taxi tests and 24 flights at the Gromov Flight Research Institute in Zhukovsky, the aerodynamic characteristics of the Buran-class orbiter were validated and an autonomous landing system was developed, along with flight documentation. If the program was continued, OK-GLI was to be used for future Buran crew training.

OK-GLI is similar in design, systems and equipment functioning during descent and landing to flight orbiters, but unlike flight orbiters it sports a total of four jet engines. The two angled nacelles either side if the tailfin housed the “standard” non-afterburning Lyulka AL-31 units, which were part of the flight orbiter design at the time. The two afterburning AL-31’s mounted on pylons either side of the aft fuselage provide the thrust needed for the orbiter to take off on its own. A sensor boom was attached to the orbiter’s nosecap to collect angle of attack and slip angle data during the flights. Using standard landing gear, the orbiters’ wings sit at a neutral angle of attack and don’t generate enough lift for take-off from a runway. To solve this problem, a nose gear extension was fitted to OK-GLI, raising the angle of attack to around 4° and drastically increasing the lift generated by the wings. The airframe is built to the standard specification, but some components were replaced by mass simulator and instead of silica thermal protection tiles, the ones on OK-GLI were made from plastic foam.

According to one source, the designation BTS is said to stem from a cover story where the workers would say that the orbiter covered in foam tiles was a heavy-lift transport aircraft for cryogenic materials. “BTS” is therefore short for Bolshaya Transportnaya Sistema or Large Transport System. [6]

Horizontal flight tests with OK-GLI were used to confirm the subsonic characteristics of the orbiter, longitudinal, directional, lateral stability and controllability. Between 1984 and 1988, two flight programs were conducted for a total of 11 taxi tests and 24 flights: the main program of 16 flights and the additional program of 8 flights. During flights with both piloted and automated landings, systems needed for atmospheric flight were tested, the final approach software was developed and landing loads on the orbiter were verified. The horizontal flight tests of OK-GLI provided the first experimental data on the dynamic characteristics, which was used to improve the methods used to calculate the characteristics of the flight articles.

Most flights lasted 20–30 minutes and included two approaches. During the first one, the pilots would climb to around 4000 meters, perform the full descent until 15–20 meters above the runway, at which point they would climb back up to 4000 meters and do another approach, this time performing the landing.

After 1988 there was an attempt to restart the flight program and at least one ground run took place in December 1989. OK-GLI was henceforth kept in storage in a Gromov Flight Research Institute hangar at Zhukovsky and occasionally displayed to visitors, most prominently during MAKS air shows. In 1999 an Australian company called Buran Space Corporation chaired by astronaut Paul Scully-Power leased the orbiter for a period of 9 years to display it in Sydney during the 2000 Summer Olympics. The Mriya and VM-T were no longer available, so OK-GLI had to be disassembled and transported over water.

Just like the Buran orbiters which made the journey from the NPO Molniya plant in Tushino to Baikonur, the analogue was floated down the Moskva river on a barge, but in the opposite direction. When the program was still secret in the 80s, large containers were used for the orbiters to disguise their shape; this time OK-GLI travelled sauté, sailing past the Kremlin and the Buran model in Gorky Park.

After the journey by barge to Saint Petersburg, then Gothenburg, OK-GLI was loaded onto a container ship which set off for Canada. After a stop in New Brunswick, the container ship continued through the Panama Canal to Australia, arriving is Sydney’s Darling Harbor on February 9 2000. The orbiter was offloaded and reassembled and a temporary structure was constructed around it. After a couple months on display the ticket sales were poor and BSC defaulted on its payments to NPO Molniya and went bankrupt, with Molniya repossessing the orbiter. They did not, however, have the funds to get the orbiter back, so OK-GLI was placed in a Sydney car park and covered in tarps. A May 2002 auction set up by a local radio station failed to sell the orbiter above the 6 million AUD reserve price, but later that year a Singapore company called Space Shuttle World Tours managed to acquire it and ship it to Bahrain for the 2002 Summer Festival.

Once again, the tickets sold poorly and SSWT defaulted on their payments to Molniya, who sued them to prevent SSWT from shipping the orbiter to Thailand. OK-GLI was transported to a Bahraini storage yard, where it would end up spending the next couple of years. In September 2003, while waiting for the outcome of the Molniya-SSWT lawsuit, a marketing director at Molniya set up the sale of the orbiter to Technik Museum Sinsheim for $350,000. SSWT reportedly came up with the $160,000 they owed Molniya, but the TM Sinsheim offer was better so the sale continued with them. The marketing director was found out not to be employed by Molniya at the time of the sale and a legal battle to find the rightful owner and buyer of the orbiter commenced. After 6 years of litigation (Molniya’s costs for which ended up being covered by TM Sinsheim), the court reaffirmed the museum’s ownership of OK-GLI. In March 2008 the orbiter was shipped to Rotterdam, then reloaded onto a barge and floated to Mannheim. In June OK-GLI had finally reached its purpose-built exhibition pavilion at Technik Musum Speyer (Sinsheim’s sister museum), where it can be seen today.