Salyut-7
second-generation stations — Salyut 6 and 7: 1977-1983
Salyut 6, launched in September 1977, was the first of the second-generation Soviet space stations. Although the essential design of the space station remained the same, Salyut 6 had a major improvement: the introduction of a second operational dock ing port. With the second port, the Soviets were able to send resup ply flights to the space station and to send visiting crews who would remain on board for a week.
The resupply cargo vehicle is a modified Soyuz with the life sup port systems and heat shield removed to maximize the volume and weight available for cargo. Called Progress, it has the disadvantage of being a one-way vehicle only—it burns up during reentry since there is no heat shield. Thus the Progress vehicles cannot be used to return material to Earth, such as the results of the various experiments conducted by space station crews. Progress made its first flight in 1978 and was used to transfer fuel into the tanks of the space station, the first time an in-space fuel transfer was accom plished.
With Salyut 6, the Soviets had created a facility that could remain operational for much longer periods of time than the previous space stations. In fact, it operated for almost 5 years until it was replaced by its cousin, Salyut 7, in 1982. Since the space sta tions were so similar, their missions through the end of 1983 will be discussed jointly here. Salyut 7 operations from 1984 to 1986 are discussed in Chapter 2. In 1979, the Soviets introduced a new vari ant of the Soyuz spacecraft, designated Soyuz T. The last flight launched under the original designation was Soyuz 40 in 1981. All flights to Salyut 7 were made on Soyuz T spacecraft.
During the Salyut 6 era, crews extended the duration of piloted space activities to 185 days. This was increased to 237 days on Salyut 7. The crews performed a wide variety of experiments in materials processing, earth resources, biology and astronomy. They are summarized below.
During most of the Salyut 6 era, the United States made no piloted spaceflights. From ASTP in July 1975 to the first U.S. s pace shuttle flight in April, 1981, Soviet crews had Earth orbit to them selves. The Soviets achieved a substantial lead over the United States in using crews in Earth orbit during this period of time. One way to compare the piloted programs is to look at how many hours crews have spent in space. At the end of ASTP, the U.S. total stood at 22,504 hours while the Soviets had 10,740 hours. When the first U.S. shuttle was launched, the United States had the same 22,504 hours, but the Soviets had grown to 50,860 hours.
The Soviet accomplishments were not achieved without difficul ty, though. The first crew sent to Salyut 6 (Soyuz 25) was unable to achieve a hard dock; Soyuz 33 in 1979 had to effect an emergency return to Earth when one of its engines failed just prior to docking, Soyuz T-8 was unable to dock with Salyut 7, and the Soviets had another near fatal disaster with the first attempt to launch Soyuz T-10. 8 Both space stations required substantial repairs by their crews, who also had to install additional solar panels to Salyut 7 to increase the amount of electrical power available for experiments.
Operational considerations with Salyut 6 and 7 were also daunting, and procedures have not changed with the new Mir space sta tion. For example, visiting crews, who remain on board a space sta tion for a week, usually dock at the aft port since the ferry craft for the main crew is at the forward port. The Soyuz is only rated for approximately 90-days in a powered down condition (as demon strated by Soyuz 20, although in at least one case—Soyuz T-9—it was somewhat longer), so the long duration crews must switch spacecraft with their visitors to have a new vehicle for the journey home. This means that the visiting crew leaves by the older ship docked at the forward port, leaving the newer spacecraft at the aft port. Progress cargo spacecraft must dock at the aft port, however, since the refueling lines are located there. To free the aft port, the long duration crew must put on their spacesuits, enter the Soyuz, undock, wait while ground controllers rotate the space station 180 degrees, and then redock, now at the forward end of the station. This procedure, still being used in 1987, has become routine, but is time consuming. Added to an already busy schedule for the crew, it is a nuisance at best to have to perform such a procedure several times during a mission.
Another operational inconvenience is the inability of Progress to return material to Earth. The film cassettes from remote sensing cameras, ampules processed in materials processing furnaces, and other experimental results must await the return of the long-dura tion crew or a visiting crew before being delivered to the scientists on the ground for analysis.
Part of the solution to this problem was the development of a modular addition to the space stations that can include a descent portion. The first test of a prototype of this module, to which the Soviets have yet to ascribe a formal name, was Cosmos 929. Launched in 1977, its mission remained obscure to Western ana lysts until the flights of Cosmos 1267 in 1981 (which docked with Salyut 6 after the final crew had left) and Cosmos 1443 in 1983 (which docked with Salyut 7 before the Soyuz T-9 crew arrived).
At the time of the 1983 mission, the Soviets admitted that Cosmos 929 had been the first of the series, and described Cosmos 1443 as a multipurpose module that could serve as a space tug, moving spacecraft from one orbit to another; a cargo vehicle that could take 2.5 times as much material into orbit as the Progress spacecraft; and as an extension to the space station, adding 50 per cent more habitable volume. These modules are approximately the same size as the Salyut space stations, and all three had modules which were detached and recovered on Earth. It is not known what was carried by those related to Cosmos 929 and 1267, but Cosmos 1443 returned 350 kilograms of material, including the results of 45 experiments and pieces of equipment that had functioned on the space station to enable studies of how they had deteriorated. 9 Western analysts have noted the similarity between these "Cosmos 929 type" modules and the "military" Salyut space stations (Salyut 3 and 5) which also ejected capsules for recovery on Earth. It is pos sible that the Cosmos 929 type modules and the military Salyuts are of the same design, a derivative of the basic Salyut.
SALYUT 6 AND 7 ACTIVITY SUMMARY: 1977-1983
Salyut 6 was occupied by 16 crews and Salyut 7 by four crews through 1983. Two crews were unable to dock with Salyut 6 and one with Salyut 7. Eighteen Progress missions resupplied the space stations, and there were two Cosmos 929 type modules that docked with them.
Of the missions, eight were the main crews who remained on board for relatively long periods of time or had specific tasks to ac complish: Soyuz 26/27, Soyuz 29/31, Soyuz 32/34, Soyuz 35/37, Soyuz T-3, Soyuz T-4, Soyuz T-5/T-7, and Soyuz T-9. The other spacecraft carried the "visiting" crews, some of which were all- Soviet, but many that included representatives from other coun tries. Between 1978 and 1983, individuals from 10 countries made voyages to Salyut 6 or 7: Bulgaria, 10 Cuba, Czechoslovakia, East Germany, France, Hungary, Mongolia, Poland, Romania, and Viet nam.
Tables 3 and 4 summarize missions to Salyut 6 and 7 through 1983. As noted earlier, the Soviet main crews often switch spacecraft with a visiting crew. A mission designated Soyuz 26/27, for example, indicates that a crew was launched into space on Soyuz 26, but returned to Earth on Soyuz 27.
SALYUT 6 AND 7 EXPERIMENTS: 1977-1983
The crews of Salyut 6 and 7 spent by far the greatest amount of their experimental time on materials experiments and remote sensing of the Earth. The crews also conducted wide ranging experi ments in space biology and medicine (discussed separately), atmos pheric studies, and astronomical observations.
Materials Processing and Other Materials Experiments
The Soviets conduct a great many materials science experiments, most of which can be described as materials processing, although some are studies of how materials react to the conditions of space- flight. For example, the crews will place various materials (rub bers, etc.) in the airlock of the space station for days or weeks to determine how they deteriorate over time.
Of most interest in the West are Soviet experiments in materials processing. During the Salyut 6 era, the Soviets used two fur naces—Splav (Alloy) and Kristall (Crystal)—to conduct over 300 ex periments. Among the most often used materials were: gallium ar senide, cadmium- mercury-telluride, indium antimonide, indium ar senide, cadmium sulphide, and germanium. Little is known of the results of these experiments, although the Soviets did announce that space-processed samples of cadmium-mercury-telluride were part of an infrared scanning device used on a late Salyut 6 mission to monitor body temperatures. At least three Soviet books have been published in English on materials processing experiments in the Soviet space program that provide a wealth of information on the science of materials processing in space as understood in the Soviet Union. Regrettably, few specific details are provided on indi vidual experiments, although the books contain tabular summaries of experiments that have been conducted. (11)
Another materials experiment on Salyut 6 used a device called Isparitel (Vaporizer) to study the processes of evaporation and condensation of different materials. Coatings of silver, gold or alloys containing aluminum, copper and silver were sprayed onto metal, glass or plastic with electron guns. This followed the successful ex periment on Salyut 4 to recoat the solar telescope.
SALYUT 6 AND 7 EXPERIMENTS: 1977-1983
The crews of Salyut 6 and 7 spent by far the greatest amount of their experimental time on materials experiments and remote sensing of the Earth. The crews also conducted wide ranging experi ments in space biology and medicine (discussed separately), atmos pheric studies, and astronomical observations.
Materials Processing and Other Materials Experiments
The Soviets conduct a great many materials science experiments, most of which can be described as materials processing, although some are studies of how materials react to the conditions of space- flight. For example, the crews will place various materials (rub bers, etc.) in the airlock of the space station for days or weeks to determine how they deteriorate over time.
Of most interest in the West are Soviet experiments in materials processing. During the Salyut 6 era, the Soviets used two fur naces—Splav (Alloy) and Kristall (Crystal)—to conduct over 300 ex periments. Among the most often used materials were: gallium ar senide, cadmium- mercury-telluride, indium antimonide, indium ar senide, cadmium sulphide, and germanium. Little is known of the results of these experiments, although the Soviets did announce that space-processed samples of cadmium-mercury-telluride were part of an infrared scanning device used on a late Salyut 6 mission to monitor body temperatures. At least three Soviet books have been published in English on materials processing experiments in the Soviet space program that provide a wealth of information on the science of materials processing in space as understood in the Soviet Union. Regrettably, few specific details are provided on indi vidual experiments, although the books contain tabular summaries of experiments that have been conducted. 11
Another materials experiment on Salyut 6 used a device called Isparitel (Vaporizer) to study the processes of evaporation and condensation of different materials. Coatings of silver, gold or alloys containing aluminum, copper and silver were sprayed onto metal, glass or plastic with electron guns. This followed the successful ex periment on Salyut 4 to recoat the solar telescope.
On Salyut 7, the emphasis was on electrophoresis experiments using the Tavria unit. The cosmonauts experimented with urokin-ase and interferon and found it possible to purify substances be tween 10 and 15 times better than on Earth and the productivity in space was reported to be hundreds of times higher. A super-pure protein substance was produced from the membranes of an influen za virus, and Soviet scientists commented that the 35 milligrams produced by the cosmonauts was enough for several months of re search, and that it had become a standard against which to com pare other vaccines.
Also on Salyut 7, the Pion unit was used to study heat and mass transfer in, and the physics of, multiphase media in weightlessness. The apparatus recorded changes in the density and temperature of substances as the container in which they were held was heated. The processes were recorded on film and videotape using a holo graphic device.
As already noted, in 1984 the Soviets published a book explaining their current understanding of materials processing in space. In the preface to the book, the editor, V.S. Avduyevsky, summarized the conflicting results that had been obtained:
The experiments yielded specimens of semiconductors, metals, glasses and medico-biological materials which outper formed similar specimens made with the same equipment on the Earth. However, this improvement was not consistent; sometimes the materials made in outer space would even show substandard performance. Some of the results, on the other hand, came as a surprise, conflicting, as they did, with the theoretical models devised for the experiments.
With this came the realization that there was a need for fun damental research which would lay a scientific basis for fur ther advances in space technology in general and in the prepa ration of high-performance materials on board space vehicles, in particular.
This book is an attempt to fill the need. 12
The comments make clear that despite years of experiments, the Soviets have much research to do, and indeed the experiments have continued as discussed in subsequent chapters.
Remote Sensing
Although the Soviets can acquire remote sensing images with automated spacecraft, traditionally they have relied on space sta tion crews for the majority of their remote sensing effort. Two per manently installed cameras account for most of the work: the MKF-6M multispectral (6 bands) camera developed by East Germa ny, and the KATE-140, a wide angle, stereographic, topographical camera for making contour maps. Resolution of the MKF-6M is thought to be about 20 meters. There also were several hand-held cameras and binoculars that the cosmonauts could point out the portholes. In addition, the Bulgarians provided a 15 spectral band spectrometer (Spektr-15) for Earth observations from Salyut 6.
The orbital inclination of Soviet space stations (51.6 degrees) does not allow full coverage of the Earth, but the most populated areas can be observed. The Soviets frequently cite the advantages of space platforms for remote sensing compared to surveys using air craft or other means. From 1977-1980, TASS reported that 9,500 photographs had been taken with the MKF-6M and another 4,500 with the KATE-140. Following the Salyut 6 missions, an article in the Soviet newspaper Izvestiya stated that the economic effect of the remote sensing effort exceeded 56 million rubles and the time required to create cartographic documentation was shortened by 75 to 80 percent. Attention to remote sensing surveys did not diminish during the Salyut 7 missions, and by the end of 1983 another 23,000 photographs had been taken with the MKF-6M and KATE- 140 instruments. One improvement on Salyut 7 was the use of a television apparatus called Niva to record and relay information back to Earth so that researchers on the ground would not have to wait until the film cassettes could be returned to Earth.
Astronomy
Only a small amount of time was spent on astronomy during the Salyut 6 and 7 missions. The most important experiment involved deploying a radio telescope from the aft docking port of Salyut 6. Called the KRT-10, it was a 10-meter diameter radio telescope used for three weeks of observations of the Milky Way and Pulsar 0329. Interferometry studies were also conducted in conjunction with a 70 meter telescope in the Crimea. Western scientists familiar with the data from the KRT-10 reported that it was of low quality. One possibility is that the antenna did not fully deploy. When cosmo nauts attempted to jettison the antenna to free the docking port, they found that it was caught on part of the exterior of the space station and they had to perform a spacewalk to free it. The Soviets have not clarified whether the problem developed when they un furled the KRT-10 or when they attempted to detach it.
On Salyut 7, the Soviets used two French astrophysics experi ments (Piramig and PCN), an X-ray spectrometer called SKR-02M, and a reflecting X-ray telescope (the RT-4M). The SKR-02M was used for interstellar observations, while Piramig was used for studying the interplanetary medium and galaxies in the visible and near-infrared bands. PCN was used mostly for atmospheric studies, although some observations of astronomical objects were made. Little information is available on the RT-4M.
Atmospheric Studies
Salyut 6 carried the BST-1M sub millimeter telescope for atmos pheric research. The cryogenically cooled sensors needed to be cali brated each time the instrument was used and the device required a considerable amount of electricity (1.5 kw). As a result, it was used infrequently. Its primary task was to provide data on the ozone layer.
The Yelena gamma ray experiment and the Bulgarian Duga elec-trophotometer were also used for atmospheric studies on Salyut 6. On Salyut 7, the crews did a small amount of atmospheric studies using the Piramig, PCN and SKR-02M instruments discussed above.
SALYUT 7: 1984-1986
Activities that took place on Salyut 7 during 1982 and 1983 have already been reviewed. This chapter details the operational and experimental activities of the main crews that occupied the space sta tion during 1984 and 1985, together with the visiting crews in those years and the Soyuz T-15 visit in 1986. These were very active years for Salyut 7 that included major repair work, the first crew rotation, and a vast expansion of the use of extravehicular activity by Soviet crews. At the end of the Soyuz T-15 visit to Salyut 7 in 1986, the Soviets boosted it (using Cosmos 1686 to which it is still attached) into a high orbit (approximately 500 kilometers circular) and announced that they would monitor the station to see how its systems degrade over time. They left open the possibility of a return "rendezvous" mission in a few years to retrieve samples from the space station itself for examination on Earth. For more information on the status of Salyut 7, see the section entitled "Soyuz T-15" below. Since the experiments were conducted by many different crews, they are consolidated in the first section. In formation on individual crew operations for each of the crews that occupied Salyut 7 from 1984 to 1986 follows.
Experiments
It is interesting that so many experiments were able to be con ducted aboard Salyut 7 from 1984 to 1986 since the crews spent so much of their tune on operational tasks. Although they were on the space station for 237 days, for example, the Soyuz T-10/T-11 crew often found itself performing EVAs (a total of six); unloading Progress cargo craft (five were launched during their mission); or working with the two visiting crews (Soyuz T-11/10 and Soyuz 12). The situation was not much better for the 1985 Soyuz T-13 and T- 14 crews. The T-13 crew spent most of its time reviving the space station after a major electrical failure, and the productivity of the T-14 crew was hampered by the illness of its commander which ul timately led to an emergency termination of the mission. The final mission to Salyut 7, Soyuz T-15, simply "dropped over" from the new space station Mir to complete activities that were not finished by the T-14 crew. Among their tasks was performing two more EVAs.
Every task on board the space station is, in a sense, an experi ment. The EVAs are important for the future of the Soviet space program. Medical examinations are required to determine how humans withstand weightlessness, even the rest days (every Saturday and Sunday) are important to psychological adaptation to long duration spaceflight. All of these activities, however, reduce the time available to conduct what are traditionally thought of as "ex periments" in materials processing, remote sensing, atmospheric and astronomy studies. The impression in the West that the Soviet crews had been able to accumulate hundreds of hours performing these more traditional experiments is somewhat overstated, al though they certainly have considerable more experience than U.S. crews.
The cosmonauts "work" eight hours a day, five days a week, on average. The rest of their time is spent on routine chores: exercis ing (two or two and a half hour a day is required), eating, sleeping, cleaning, communicating with Flight Control, and so forth. Ev erything else—unloading cargo ships, performing EVAs, doing medical checks, and conducting "experiments"—must be accomplished essentially in a 40 hour work week. This does not leave as much time for materials processing and other experiments as might be presumed.
Despite the heavy load of operational and routine assignments they had, crews that visited Salyut 7 from 1984 to 1986 managed to accomplish a great deal. The 237-day Spyuz T-10/T-11 crew per formed more than 550 scientific experiments, took 4,400 photo graphs with the MKF-6M camera and another 1,640 with the KATE-140. At the end of the Soyuz T-14 mission, which was both the first transfer of crew operations (from Soyuz T-13) and the first mission terminated early because of illness, it was reported that the crew had completed 400 scientific experiments and photo graphed some 16 million square kilometers. It was not clear if this was just for the Soyuz T-14 part of the mission, or the combined Soyuz T-13/T-14 time in space. No specific numbers were given for the T-15 crew that spent 50 days on Salyut 7 in 1986 sandwiched between activities on the new space station Mir, but they did perform at least a few experiments.
In total, these crews to Salyut 7 performed a total of 10 EVAs. Most of these (six by the T-10/T-ll crew and one by the T-13 crew) were operational, not experimental, and are discussed under the specific mission rather than here. Only those that were primar ily experimental (the T-12 EVA for testing a device for welding and spray coating, and the two by the T-15 crew for space construction and welding) are described in detail in this section.
References:
1. SOVIET SPACE PROGRAMS: 1981-87, PILOTED SPACE ACTIVITIES, LAUNCH VEHICLES, LAUNCH SITES, AND TRACKING SUPPORT PREPARED AT THE REQUEST OF Hon. ERNEST F. HOLLINGS, Chairman, COMMITTEE ON COMMERCE, SCIENCE, AND TRANSPORTATION, UNITED STATES SENATE, Part 1, MAY 1988, printed for the use of the Committee on Commerce, Science, and Transportation, U.S. GOVERNMENT PRINTING OFFICE, WASHINGTON, D.C. 1988
8 New details emerged in 1987 about the Soyuz T-10A near-tragedy that occurred on Septem ber 26, 1983 (see previous edition of this report). The commander of the mission, Vladimir Titov, and a Soviet journalist described their separate feelings during the emergency in an interview for the Soviet newspaper Krasnaya Zvezda (Red Star) on May 30, 1987. The journalist recalled his reactions at seeing flames envelope the launch vehicle, while Titov recounted his own sensa tions during the operation of the emergency rescue system (abort tower). He concluded by saying that "We are often asked, was it frightening? I do not know what to answer. I never thought about it. That is the truth!" Later in the year, Lt. Gen. Shatalov, head of the Cosmo naut Training Center, revealed that the crew had experienced an acceleration of 15-17 g's during the escape maneuver, significantly higher than originally assumed by Western observers (8-10 g's). Titov finally succeeded in getting aboard a space station, Mir, at the end of 1987.
9 In 1986, the next in the series, Cosmos 1686, was launched to dock with Salyut 7. It did not have a return module. At the end of 1987, it was still docked with Salyut 7 in orbit.
10. Soyuz 33 carried the Bulgarian cosmonaut. A failure in the Soyuz main engine prevented docking with the space station. The Soviets plan to fly another Bulgarian in 1988.
11 The two Avduyevsky books cited in footnote 7 plus: Regel, Lia. Materials Science in Space: Theory, Experiments, Technology. English translation by J.M. Haynes, Bristol University, UK and H. Rodot, CNRS, France. New York, Halsted Press, 1987 (published in Russian in 1984).
12 Avduyevsky, ibid
