Deployment, servicing, and retrieval missions

While Buran was never seriously considered for routine satellite deployment mis­sions, the Russians did look at the possibility of placing big payloads in the cargo bay. Among these were spacecraft developed as part of a Soviet “Star Wars’’ program in which NPO Energiya was given the leading role in 1976. It would have seen the use of space-based assets to destroy enemy satellites, ballistic missiles, and ground-based targets. Making maximum use of existing technology, NPO Energiya tabled proposals for “battle stations’’ that would be based on Salyut and Mir technology.

For anti-satellite operations the idea was to develop two types of Salyut look – alike space stations, one equipped with missiles (Kaskad) and the other with laser weapons (Skif). The stations carried much larger propellant supplies than their

Mir-type “battle station” with Buran-based combat modules (source: RKK Energiya/ www. buran. ru).

progenitors, but had man-tended capability, being able to house two-man crews for up to seven days. Kaskad stations would target high-orbiting satellites, while the Skif stations were to knock out satellites in low orbits. Experimental versions of these stations would be orbited by the Proton rocket, but the operational ones were designed to go up in the cargo bay of Buran. The Soviet orbiter would also be responsible for refueling missions to these stations. In 1981 work on Skif/Kaskad was transferred to Energiya’s new KB Salyut branch, which dropped the Salyut – based design in favor of 100-ton Energiya-launched spacecraft (see Chapter 6). There are no indications Buran still had any role to play in Skif/Kaskad from that moment on.

For destruction of ground-based targets the NPO Energiya planners came up with a Mir-type core module with four specialized modules docked to a ball-shaped multiple docking adapter. Attached to the axial front port was a module with an additional multiple docking adapter that served as the berthing place for so-called “combat modules’’ resembling Buran orbiters without wings or other aerodynamic surfaces. After undocking from the station, the unmanned combat modules would maneuver to the proper location and then deploy small vehicles tipped with (un­specified) weapons that could re-enter the atmosphere. These could be either ballistic – type vehicles or lifting bodies. One design studied for these re-entry vehicles was based on the BOR-4 lifting bodies. Presumably, the idea was that after deploying the weapons the Buran-based combat modules would return to base to be reloaded with new ones [35].

One big military satellite intended for launch by Buran was Sapfir (“Sapphire”), a 24-ton optical reconnaissance satellite developed by TsSKB in Kuybyshev. This was equipped with a 3 m diameter telescope to photograph targets of interest in great detail. The idea was that Buran crews would regularly visit Sapfir for servicing. Although the telescope for the first such satellite was nearly finished, the project was discontinued after the cancellation of Buran, since the Proton rocket was not capable of orbiting the satellite [36].

Another big payload eyed for launch by Buran was ROS-7K (“Radiotechnical Orbital Station”), a man-tended Salyut-derived space station equipped with a 30 m diameter dish antenna called KRT-30. Capable of serving as a radio telescope and a radar, the KRT-30 was to be used for all-weather remote-sensing, astrophysical, and geophysical observations and target localization for the Soviet Navy. Together with the ground-based components needed to receive, process, and distribute data from the station, the system was called Gals (“Tack”, in the nautical meaning), an indica­tion that its observations in support of the Soviet Navy were seen as its primary mission.

Flying in a circular 600 km orbit inclined 64.8° to the equator, ROS-7K could house two-man crews up to seven days for maintenance operations and could be refueled in orbit. The complete ROS-7K with the stowed KRT-30 fitted in the cargo bay of Buran, although launch by the Proton rocket was studied as an alternative. Buran was also supposed to fly a technology demonstration mission in support of ROS-7K/Gals called “Karat”, but no further details on this are available. Gals was studied at NPO Energiya from 1978 until 1987 [37].

Buran (along with Proton) was also considered to launch a giant space tug powered by a nuclear electric engine. Called Gerkules (Russian for “Hercules”), the tug was to be stationed in a 200 km orbit and one of its tasks was to maneuver 100-ton spacecraft launched by Energiya to geostationary orbit. Given the 35m length of the tug, several missions would have been required to assemble it in orbit. Gerkules studies at NPO Energiya began in 1978 and lasted until at least 1986 [38].

Another exotic payload studied for launch by Buran or Proton was an experi­mental, orbiting solar power station, consisting of a solar tug and a dish antenna (based on the KRT-30). Deployment of the experimental solar power station would have required two Proton or Buran launches [39].

NPO Energiya also looked at so-called “Experimental Space Apparatuses” (EKA) that appear to have been prototypes of expensive new satellites that would be thoroughly checked out in orbit by Buran. The crew would, for instance, check if vital systems (such as various appendages) worked and carry out repair work if necessary. The EKA could then later be revisited for maintenance operations or the retrieval of valuable parts for analysis on Earth or reuse on later satellites [40].

Another future assignment for Buran occasionally mentioned by Russian sources was the retrieval of satellites from space. While this may have sounded attractive, such missions usually require that satellites are designed to be picked up by an orbiter—that is, have grapple fixtures for the orbiter’s remote manipulator system and be small enough to fit in the payload bay—and, above all, circle the Earth in orbits that can be reached by it. In practice, that would have virtually limited such

The Salyut-7 space station.

missions to satellites deployed by the orbiter itself and not equipped with a kick motor to be boosted to high orbits. The original 1976 government/party decree on Buran had called for the development of a reusable space tug (11F45) to operate between low and high orbits, but that was never developed. In one interview Yuriy Semyonov mentioned the possibility of retrieving nuclear-powered satellites that threatened to fall back to Earth [41]. The only such satellites operated by the Soviet Union were the US-А radar ocean reconnaissance satellites and it looks unlikely they could ever have been retrieved by Buran, if only because of the radiation threat to the crew.

One other mission studied for Buran was to retrieve elements of the Salyut-7 space station. Launched in 1982, Salyut-7 played host to its final crew in May 1986 before definitively passing the torch to Mir. However, rather than deorbiting it, as had been the usual practice with earlier Salyuts, the Russians boosted the station and the attached Kosmos-1686 spacecraft (a Transport Supply Ship or TKS) to a 474 x 492 km storage orbit in August 1986 to see how well their systems would stand up to a prolonged stay in space and use that experience in designing future spacecraft. Some two weeks after the maneuvers Yuriy Semyonov said in an interview that “in a few years a group of cosmonauts could be sent to Salyut to study the state of the orbital complex” [42].

In December 1988, with Buran no longer a state secret, Semyonov acknowledged that the idea was to send a Buran crew to Salyut-7 in 1995-2000 and retrieve parts of the complex for detailed analysis on Earth, adding this would provide invaluable data on prolonged exposure of materials to space conditions [43]. Some reports at the time suggested the plan was to retrieve the entire Salyut-7 space station, but given the technical complexity of such a mission, that never seems to have been the intention.

However, Salyut’s orbit decayed much faster than predicted due to unexpectedly high solar activity in the late 1980s/early 1990s that caused the upper layers of the atmosphere to expand considerably. On top of that, Kosmos-1686 suffered a failure of its electrical systems in December 1989, making it impossible to use the vehicle’s thrusters to keep the station in a gravity-gradient mode. With little fuel left in Salyut’s own tanks, the complex eventually made an uncontrolled re-entry on 7 February 1991, showering debris over South America.