Inside the Buran
The Buran was a reusable orbiter capable of putting different payloads into space and bringing cargoes back to Earth. Some specialists speculate that the rocket-powered glider might have hypothetically recovered the Mir space station piece by piece. Its cargo compartment was capable of easily accommodating any module of the Soviet space laboratory, which would be deorbited and dumped in 2001. The designers suggested using the same compartment for the re-entry capsule Soyuz during manned space flights. In an emergency, the crew would get into the capsule for urgent evacuation.
Plans had been in the works for using the Buran not just for carrying space stations’ crews or recovering defunct satellites, but for military purposes as well. It was precisely the combat potential of rocket-powered gliders that explained why the Soviet Union was in such a rush to come up with a world-class rival to America’s space shuttles.
Work on the Energia-Buran program commenced in 1976, five years after America’s Space Shuttle. Outwardly similar, the design proposed by Soviet engineers greatly contrasted from their US counterpart.
Up Into Space
The Energia-Buran and the Space Shuttle were cutting-edge space systems that fundamentally differed from their predecessors in structural design. Each was based on the multi-stage rocket design concept, which Konstantin Tsiolkovsky predicted back at the beginning of the 20th century. Both reusable launch vehicles had two-stage propulsion systems. Whereas the US Space Shuttle took off thanks to solid-fuel rocket boosters and its own propulsion engines that worked on propellant from an external tank, Soviet designers combined the functions of these two blocks into one rocket — the Energia, which was a two-stage launch vehicle. This enabled Buran to be equipped with a far more functional orbital maneuvering system instead of its own bulky propulsion device.
Both spacecraft had their own orbital insertion and maneuvering engines. This made the launch ecologically cleaner, since near-Earth space was not littered with spent rocket stages. The separated units either burned up in the atmosphere, or returned back to Earth for overhaul, maintenance and repeated use. The Space Shuttle’s first stage was reusable. A similar solution was going to be employed in the Energia-Buran project.
One of the advantages of the Soviet system was that the Energia was not designed strictly for the Buran alone. It was capable of orbiting any other payload of up to 105 tonnes, if needed.
The overall thrust of the Energia’s engines was 170 million horsepower. That was enough for missions to the Moon and beyond. However, the rocket was destined to fly only twice. The first time was during its initial test on May 15, 1987 and the second time, on November 15, 1988 when the Buran was attached to it.
This duo’s historical flight could have taken place 17 days earlier, on October 29, if the computer had not stopped the countdown 51 seconds ahead due to a problem in one of the Energia’s systems. On November 15, the rocket blasted off and orbited the spaceplane as planned despite bad weather with strong wind and fog.
Journey back to Earth
The orbital part of the flight was the most predictable for the designers and engineers. The experience of launching Soyuz rockets, accumulated by 1988, was quite enough, so very few doubted that the Buran would cope with this task. The spacecraft spent just 94 minutes in orbit, although it was capable of staying in space for up to 30 days.
Everybody worried about the landing, which was to be wholly computer-controlled for the first time. The seats in Buran’s cockpit were empty. Its success depended entirely on the performance of the on-board computer and the ground navigation systems. Incidentally, that was another fundamental feature that distinguished the Buran from the US Space Shuttle. Automatic landing was absent from the range of the US spacecraft’s capabilities.
The Americans’ main mode of operating the Space Shuttle was manual. Our standard landing mode was automatic. The idea was the pilot merely sits tight in his seat keeping his hands off the joystick. Why? As soon as he lays hands on the steering rod, Buran’s automatic system is turned off.
In fact, any spacecraft’s re-entry is tantamount to a free-fall. The Buran began its descent at a speed nearly 30 times the speed of sound. The area where it would leave orbit was vital to the place where it would land, either the main site near Baikonur or one of its two reserves: one in Crimea or the other in the Primorye Region along the Pacific. Changing the landing site after re-entry would be impossible, because the Buran, just like the Space Shuttle lacked air jet engines. After the beginning of the descent, the spaceplane set its course towards Baikonur.
Special heat-resistant tiles covering the Buran’s body protected it from the effects of plasma during re-entry. The tiles were capable of withstanding temperatures of up to 1,260 °C. A total of 37,500 tiles were made for the Buran. While the spaceplane was in flight, a mere six of them were lost and about a hundred sustained damage.
The most dramatic moment for spectators was when the Buran, while heading for the runway, made a sudden sharp turn away from the expected flight path. The onboard computer’s decision looked so strange that some of those on duty at Mission Control, suspicious the control system had broken down, even suggested exploding the spacecraft. As the Buran’s chief designer Gleb Lozino-Lozinsky recalled later, some had already started drafting a news release for TASS saying the experimental flight ended in failure. In the meantime, the Buran performed a neat and smooth loop to make a perfect landing, touching the runway just one second ahead of the estimated time.
As it turned out later, the Buran’s computer had received a warning of a strong side wind from ground stations. The spacecraft’s electronic brain took it into account and promptly opted for a safer route of approach.
Throughout the final phase of the flight, including the spacecraft’s unexpected maneuver, test pilot Magomed Tolboyev escorted the Buran on a MiG-25 jet. Roscosmos’s TV studio shared some unique footage filmed from the fighter jet’s cockpit with TASS.
The runway there was ideal. When it was still being built, soldiers literally polished it by hand. I saw them do that myself. One day Gleb Lozino-Lozinsky arrived for an inspection to test the quality. He placed a glass of water on the car’s hood and went on a test ride along the runway. Not one drop was spilled. The surface was perfect.
The touchdown was far softer than the engineers had anticipated. As a result, the drogue parachutes, which were designed to open up upon the first touchdown impacting the landing gear struts, had actually activated nine seconds later, when the spacecraft was already rolling and loosing speed. At that very moment the Buran went down in history as the first-ever orbiter to have accomplished a computer-controlled landing.
One for all
The Buran was anticipated to provide an alternative to costly single-use launch vehicles. Its declared life cycle was 100 Earth-Space-Earth voyages. Its would-be successors, the Burya and Baikal, would have had the same endurance. Alas, none of them would ever fly. In 1992, the orbital space shuttle program was abandoned due to financial constraints.
The Buran no longer exists. In 2002, it perished when the roof of an assembly and test hangar at Baikonur where it was kept, caved in. The Burya and Baikal, mothballed in other hangars, and a series of scale mockups, some of them on museum display, is all that is left of the legendary Soviet space program.
The Energia-Buran launch facilities at Baikonur remain idle, although 30 years ago many were certain reusable orbiters would be blasting off every month.
An abundance of expertise created especially for Soviet spacecraft continue to be used in a variety of fields. It’s been utilized from aircraft and machine building to farming. Although the program for orbital shuttles sank into oblivion, the saga of reusable space systems carries on. Designers keep testing recoverable space units, meant not only for near-Earth missions, but also for deep space voyages.