FULL-SCALE AND CREW CABIN MODELS

Rather than rely heavily on computer modeling, the Russians built at least seven full-scale test articles of Buran to investigate a variety of manufacturing, assembly, and flying quality characteristics as well as handling procedures. A similar approach was followed for space stations and their modules. By contrast, NASA built just two full-scale Orbiters for test purposes—namely, Enterprise (OV-101) and Structural Test Article 099 (later turned into OV-099 Challenger).

The seven full-scale vehicles were:

– OK-M (serial nr. 001): a full-scale model for structural tests at NPO Mol – niya. It mainly served as a test bed for the 002 vehicle used in the approach and landing tests. It had the same mass characteristics as the real vehicle, carrying mass models of on-board equipment. Later, it was supposed to be used for underwater EVA training in a hydrotank facility at Star City, but it was rebuilt as a tourist attraction and delivered by barge to Gorkiy Park in Moscow in 1993, where it can still be seen today.

– OK-GLI (serial nr. 002): a full-scale model used for approach and landing tests in 1985-1988 (see pp. 297-309).

– OK-KS (serial nr. 003): a full-scale model for electric and software tests, delivered to NPO Energiya in August 1983. Also used for electromagnetic interference tests. OK-KS served as a test bed to troubleshoot numerous problems that cropped up during the construction of the first flight vehicle. Various software programs for the maiden flight were tested on OK-KS.

– OK-ML1 (serial nr. 004): a full-scale model flown to Baykonur by the VM-T Atlant in December 1983 for preliminary fit checks of ground equipment in the Buran assembly building and on the runway. On one occasion it was mated with an Energiya for dynamic tests both at the UKSS and the left Energiya-Buran pad. For a while it had mock-up turbojet engines installed on either side of the vertical stabilizer.

OK-KS at NPO Energiya (source: www. buran. ru).

– OK-TVA (serial number 005): a model for thermal, acoustic, and static vibration tests at TsAGI. To facilitate testing, OK-TVA was not assembled as a single vehicle, but split into several real-size sections that could be tested individually: a forward fuselage with crew cabin, mid and aft fuselage, two wings, a vertical stabilizer, elevons, a body flap, a nosecap, and several sections of the leading edges of the wings. The components were covered with standard thermal protection material, among other things to see whether that would be affected by slight deformations in the underlying aluminum skin.

OK-ML1 and OK-MT in tandem at Baykonur (source: www. buran. ru).

OK-TVI at Nllkhimmash (B. Vis).

Thermal and static vibration tests took place in the TPVK-1 vacuum chamber. It was 13.5m in diameter and 30 m long and exposed components to temperatures ranging from — 150°C (using a liquid nitrogen cooling system) to +1,500°C (using 10,000 quartz lamps with a total capacity of

13.0 kWt). The test rig could apply 8,000 kN of force horizontally and

2.0 kN vertically and took the airframe to 90 percent of design load limits. Acoustic tests were carried out in the RK-1500 acoustic chamber. With a floor space of 1,500m2, it was equipped with 16 sound generators that subjected the components to 162 dB sound levels at frequencies of 50 to

2.0 Hz.

– OK-TVI (serial nr. 006): a model for thermal vacuum tests at Nllkhimmash. This consisted of a mid and aft fuselage, a vertical stabilizer, and payload bay doors with radiator panels. Some sources also mention a forward fuselage with crew cabin, although that is not seen in photographs and must therefore have been tested individually. The fuselage sections were equipped with Buran’s thermal control system to see whether that could deal with the temperature extremes in space. The components were installed in the KVI thermal vacuum chamber. With a volume of 8,500 m3, this is the largest such facility in Europe.

– OK-MT/OK-ML2 (serial nr. 015): a full-scale model flown to Baykonur by the VM-T Atlant in August 1984 for fit checks of ground equipment at the cosmodrome. It was rolled out to the pad on several occasions and used among other things for crew boarding and evacuation exercises and for load tests of the ODU engine compartment and the Auxiliary Power Units. It was also transported to the runway for crew egress training and simulation of other post-landing activities.

In addition to the full-scale models, the Russians built several crew modules for test purposes. The following have been mentioned by Russian sources, although it is not entirely clear if all were actually built or used:

– MK-KMS: crew module at NPO Energiya equipped with operational con­trol, display, and computer systems and also incorporating an airlock and docking module. A visual display system simulated the outside environment during all phases of the flight. MK-KMS was intended for training crews and Mission Control personnel. It had the same communication links with Mission Control in Kaliningrad as the ones available to Buran during an actual flight.

– MK-M: a Buran crew module placed in a vacuum chamber (VU-1000) for tests of the life support systems and medical support systems (presumably located at Myasishchev’s EMZ). It also contained an airlock and a docking module. The crew module was placed vertically in the chamber, which was 10 m wide and 11m high. Crews entered and egressed the crew module via a small tunnel attached to the mid-deck side hatch. MK-M closely mimicked a real crew cabin, carrying standard life support and thermal control systems.

Any of those systems located outside the crew cabin were also installed in the chamber in roughly the same position with respect to the crew cabin as in a real orbiter.

The cabin carried mock-ups of equipment not related to the life support system. MK-M allowed crew members to wear Strizh pressure suits that could be immediately pressurized in case of a leak. The water delivered to the crew compartment was produced in actual Buran fuel cells. It is not clear if the test stand was ever used for crew training. The plan was eventually to turn it into a so-called ground-based “analog” of vehicles in orbit, among other things to facilitate troubleshooting activities.

– MK-1KA: a crew module with nose section mounted vertically on a turntable to practice crew evacuation from the vehicle.

– MK-KB: a crew module containing mock-ups of equipment needed for the 002 vehicle.

– MK-GN: a crew module placed in a hydrolab for EVA training.

– MK-KB. E: a crew module for electrical tests, later integrated into the OK-KS vehicle.

– MK-KB. U: a crew module to study the placement of equipment and crew work stations in the cabin [15].