Ask people about the space shuttle and they think of NASA, the American space programme, the International Space Station, Challenger, Columbia and possibly an obscure Star Trek reference1. But they probably won't think of the Russian space shuttle, Buran. Its name means 'snow storm'.
The Soviet government began designing Buran in 1976 as a response to NASA's shuttle programme, and although NASA's goal was the further exploration of space, the cheaper launch of satellites (which never really materialised) and to carry out space science, the Soviets' primary goal was to carry nuclear weapons into orbit. Although allowance for some scientific research was also included into the project, the development of Buran was predominantly, another branch of the space race between the USA and USSR.
Similar to NASA's approach, the Soviets began with experimental aircraft, the MiG 105 - 11 'Spiral' experimental manned orbital aircraft (Experimental'nyj Pilotiruemyj Orbital'nyj Samolet - EPOS), which flew in 1977/78 and helped in the development of the Soviet Space Shuttle. Later they moved on to one-fifth scale models of Buran, then to a full scale atmospheric model to test the glide and landing abilities. But after just 24 flights, this vehicle was damaged and unable to fly again.
The atmospheric model was their equivalent of the Enterprise shuttle, which never flew in space but was built for atmosphere testing. Again, the Russians did things differently. The Enterprise was attached to the modified Boeing 747, flown to a specified height and released to glide back to earth. The Buran atmospheric test model had two jet engines bolted onto the side of it, at the rear.
Comparison of Designs
To simplify this comparison, the NASA shuttle will be referred to here as STS (its official designation) standing for Space Transit System. The Russian shuttle will be referred to as Buran.
The STS (or orbiter) is attached to the centre liquid fuel tank. Strapped to the sides of the tank are two solid fuel rocket boosters. Two minutes after take-off, the solid fuel boosters are depleted and jettisoned. Parachutes in their nose-cones allow them to splash down in the sea to be recovered. Seven minutes later, the centre fuel tank is jettisoned and left to burn up in the atmosphere. NASA used to paint this tank white, to match the rest of the vehicle until someone pointed out that the paint alone added seven tonnes to the craft's weight. It was more economical not to paint it, allowing for more payload instead.
In overall design, Buran is nearly identical to the STS. Immediately noticeable is a sharper-edged wing design which is squarer and reduces drag on take-off and re-entry. The Soviets did think about copying the American design exactly, but were worried about the heat build-up on the wing surface and drag during lift-off.
Buran is 4600kg lighter than the STS and can carry 5000kg more payload, with a slightly bigger payload bay. It also requires less fuel to get into orbit.
Although it carries only slightly more propellant for orbital manoeuvres, its orbital engines are significantly more powerful.
Buran and Energiya
One of the most noticeable distinctions between NASA's STS and Buran is that the Soviets placed the liquid fuel engines on the base of the centre fuel tank, rather than on the back of the shuttle. There are also four of them, rather than the three of the American version. These rocket motors were already being designed for other rockets and could be converted for the Buran's use. These engines are disposable and are destroyed along with the fuel tank on each launch. This suited the Soviet space programme better for several reasons. Firstly, designing and building re-usable engines is difficult and expensive. The three engines on the STS have caused many headaches for NASA, as they require enormous amounts of maintenance. At the time, the Soviets lacked the expertise to make these engines reusable, but were quite proficient at disposable engine design and construction. Secondly, the Soviet design can be launched without the orbiter.
The launch system, comprising the fuel tank and external solid fuel boosters, is known as Energiya. It has four boosters, rather than the two of the NASA design. The Soviets designed it to have its own guidance system, so that it can launch without the shuttle, although why anyone would want to is difficult to imagine.
At 03:00 GMT on 15 November, 1988 Buran lifted off on its maiden flight. It completed two orbits before re-entry. At 06:25 GMT it landed in Tyuratum. Its flight was limited to two orbits due to a lack of memory in the flight computer.
The flight was unmanned, for two reasons. The life support system was untested and the computer displays in the cockpit had no software, so the crew would not have been able to fly it. Additionally, the computers could not generate a display for the pilots. NASA's STS has never flown unmanned - its first flight had the minimum crew of two, a commander and a pilot.
The Buran flight was a huge technical success. The autopilot was able to correct for a 34mph cross-wind on landing; high enough for NASA to divert to their alternate landing site in White Sands.
Buran lost significantly fewer insulating tiles on re-entry, possibly due to the wing design. On the first flight of the NASA orbiter, more than 20 tiles were found to have been lost, some on take-off. Buran lost only five out of more than 38,000.
Two other orbiters were planned and construction had begun on them. The second was called Ptichka, meaning 'Little Bird'. Neither of these was completed and both were dismantled.
The End of The Buran Programme
Buran never flew in space again. Political good will faded, while a report from the Russian space agency showed that Buran was actually an enormously expensive way of getting into space. Funding was cut and in 1993 the Buran project was officially cancelled, although mothballing operations were being performed long before this. However, Buran did make one final curtain call. On 13 May, 1989, it flew attached to the back of Antonov An - 225 Mriya, which was designed specifically for this task and is the heaviest, most powerful and, in most aspects, biggest plane ever built. Both An - 225 and Buran visited the Paris Air Show a few days later. This again was a method borrowed from the Americans, who fly their shuttle on the back of a modified Boeing 747.
References and Further Reading
- Buran and STS comparison
- Buran sitting on its An-225 transport
- Technical drawings of Buran and Energiya
- Artist's impression of Buran in space
- Three elevations of Buran and Energiya