DOS Salyut Series

PROGRAM DETAILS OF MAN-RELATED FLIGHTS

By Marcia S. Smith*

1971-75

THE SPACE STATION ERA

1. Soyuz 10 and 11 with Salyut 1

By the earlier criteria listed under Soyuz 4 and 5 for a space station, the world's first such station was launched by the Soviet Union in 1971. Two missions, Soyuz 10 and 11, were sent to work with the station and it remained in orbit for about six months.

a. Salyut 1 .—Very early on April 19, 1971 , the unmanned space station Salyut 1 was launched from Tyuratam by a D-l vehicle into a 222 x 200 km orbit inclined at 51.6°. Initial announcements were vague, as usual, stating the purpose of the mission as a test of elements of the systems of the space station, and to conduct scientific research and experiments on board the craft. The station was described simply as multipurpose and complex, for carrying out diverse plans. It was not until the launch of Soyuz 11 that more details were released about Salyut, and it was initially described as 20 meters long with a maximum diameter of 4 meters. Since the original announcement, however, the length has alternately been given at 21.4 meters (5) and 23 meters (6) with a maximum diameter of 4.15 meters. (7) Later in this chapter one will see that Salyut 3 was announced as being 21 meters long, and Salyut 4 as 23 meters. It seems unlikely, due to technical and development cost constraints, that each space station would be a different length, so it is suspected that external attachments such as radio transponders are sometimes counted as part of the overall length and other times they are not.

Salyut is made of several compartments and the measurements for each of these seem uniform from one version to the next. The compartment that serves as a transfer tunnel from the ferry craft to the Space station is 3 meters long and 2 meters in diameter. The main habitable portion is comprised of three sections: The small cylinder 3.8 meters long and 2.9 meters in diameter; the large cylinder 4.1 meters long and 4.15 meters in diameter; and a cone connecting the two which is 1.2 meters long. An un pressurized service module completes the station, and it is 2.17 meters long and 2.2 meters in diameter.

The internal area of the space station is consistently listed as 100 cubic meters, and the weight of the combined Salyut/Soyuz system is consistently "over 25 metric tons". Since Soyuz is about 6,575 kg, Salyut would be in excess of 18,425 kg (estimates usually place this weight at 18,600 to 18,900 kg).

Television views showed a considerable amount of space with big chairs and several control panels. Later it was revealed there were eight chairs, seven at work stations. Altogether there were 20 portholes, some unobstructed by instruments to give a good view of the Earth and outer space.

Externally, there were two double sets of solar cell panels, placed at opposite ends, extending like wings from the smaller diameter compartments in much the same manner as the panels on the Soyuz. Also externally were the heat regulation system's radiators, the orientation and control devices. Some of the scientific instrumentation was internal, some external.

Because of the low orbit of Salyut during the time it served as Soyuz 10's rendezvous target, the station would have decayed into the atmosphere around May 3. Therefore, after Soyuz 10 had completed its mission, the onboard propulsion systems were fired to raise the orbit by about 50 km. At least twice during May the orbit was raised even more to offset orbital decay.

This procedure was also followed after the Soyuz 11 visit, this time to test the longevity of the station and to keep open the option to send another crew. But finally on October 11, its engines were fired for the last time to insure decay over the Pacific Ocean . Pravda reported on October 26, 1971 that the Salyut tasks were solved in 75 percent of cases by optical means, in 20 percent by radio-technical means, and the small balance, by magneto-metrical, gravitational, and other studies. Often synoptic readings -were taken in both the visible and invisible parts of the electromagnetic spectrum.

b. Soyuz 10-At 2354 GMT on April 22, 1971 , Soyuz 10 was launched by an A-2 vehicle into a 246 x 208 km orbit inclined at 51. 6 . The crew consisted of Col. Vladimir Shatalov, Flight Engineer Aleksey Yeliseyev, and Nikolay Rukavishnikov, described as responsible for operation of systems in the Salyut station.

Instead of making a fairly direct ascent to rendezvous with Salyut, almost 24 hours passed before this was accomplished, Salyut was maneuvered four times; Soyuz 10 made 3 principal maneuvers. One of these came 13 hours 35 minutes into the flight on instructions from the new, large tracking ship, Akademik Sergey Korolev, stationed in the Atlantic .

Automatic devices did the actual work of rendezvous until the two craft were 180 meters apart. Shatalov then took over manual control, commenting later that due to the difference in size, Soyuz seemed like a train entering a railway terminal. The crew said they were not able to see Salyut until it was only 15 km away, and then they used an optical device to see it. They described the station as very impressive, and painted in more brilliant colors than they had noticed while it was on Earth.

The docking was apparently quite nerve-wracking, with Shatalov steering while his colleagues monitored various instruments on the status of systems. Soviet commentary noted that the problems of docking with a large mass, unmanned, non-maneuvering station were quite different from the docking of two Soyuz ships, each able to adjust its position. The Russians reported that new telemetry, rendezvous and docking equipment was used for this mission.

The ships remained docked for about 5.5 hours. Television cameras mounted externally on both ships had watched the procedures of approach, docking, and separation. After the undocking, Soyuz 10 flew all around the station to take a variety of pictures, and then preparations were made for return to Earth. Retrorockets were fared at the first opportunity which would permit return in the normal recovery area, and reentry occurred as expected. The flight lasted just short of two days, and the predawn landing near Karaganda was another first in the Soviet program, since all other landings had taken place in daylight.

The early return of Soyuz 10 and the failure of the crew to transfer into Salyut suggested that the mission had not accomplished all its objectives. The Russians said that although the flight had been short, it had been scheduled to a very tight degree for the research and testing tasks which were successfully accomplished. It seems reasonable to accept the statement that the mission achieved its primary objectives of exercising the new telemetry, docking and control systems, and to recover the men, with further unmanned experiments continuing with the Salyut But it also seems likely that the total mission fell short of its engineering capabilities and Soviet hopes. Some Western observers read significance into the report that the crew was met by a smaller delegation of officials than other returning cosmonauts, although the traditional welcome was accorded the three men in the formal reception in the hall of the Great Kremlin Palace .

Possible signs of trouble in the mission include:

(1) The failure of the crew to transfer into the station after a successful mechanical docking seems surprising, especially because Rukavishnikov was a specialist in the Salyut systems. Either the hatches and air locks were not functioning properly, or there was some threat of trouble which might require a quick disconnect and return to Earth.

(2) The early return to Earth at the first opportunity suggested either trouble in Soyuz 10, or such dependence upon equipment, consumables, and systems of Salyut that when these were found to be unavailable, there was no point in prolonging the mission.

(3) When all previous Soyuz flights are plotted on a graph to compare hour of launch with number of days in flight until recovery, a very regular relationship is revealed. On this basis of estimation, the predawn launch of Soyuz 10 seemed to suggest a 30-day flight, and yet the flight terminated after only 32 orbits (2 days), with a pre-dawn landing. (8)

G. Soyuz 11 — On June 6, 1971 at 0455 GMT, Soyuz 11 (code named Yantar or Amber) was launched with a crew consisting of Lt. Col. Georgiy Dobrovolskiy, Flight Engineer Vladislav Volkov, and Salyut Test Engineer Viktor Patsayev.

The first day of flight passed routinely, with appropriate maneuvers to effect a rendezvous until Soyuz 11 was 6-7 km from Salyut, about 0426 GMT June 7. At 100 meters Dobrovolskiy took manual control. The complicated process of docking, which wasn't completed until 0745 GMT, required: initial engagement (soft-dock), making the connection mechanically rigid (hard-dock), engaging various electrical and hydraulic links, and a thorough process of establishing air-tight seals (hermetic sealing). After pressure was equalized between the two ships, the locks were opened and Patsayev transferred into the space station, soon followed by Volkov. After they turned on the systems and switched command functions of the combined craft to the central control panel in Salyut, Dobrovolskiy joined them.

After crew transfer, the Russians announced their mission as:

(1) To check and test the design, units, onboard systems and equipment of the orbital piloted station;

(2) To try out the methods and autonomous means of the station's orientation and navigation as well as the systems of controlling the space complex while maneuvering in orbit;

(3) To study geological-geographical objects on the Earth's surface, atmospheric formations, the snow and ice cover of the Earth with the aim of developing methods of using these data in the solution of economic tasks;

(4) To study physical characteristics, processes and phenomena in the atmosphere and outer space in various ranges of the spectrum of electromagnetic radiation;

(5) To conduct medico-biological studies to determine the possibilities of performing various jobs by the cosmonauts in the station and to study the influence of space flight factors on the human organism.

A summary of the cosmonauts' activities by day is presented in Table 3-2, which provides both a picture of what happened each day on this mission and serves as a sample for other space station missions in this report.

In general, health monitoring and exercises for the crew were continued throughout the mission. Some monitoring was close to continuous, some was periodic, and some was supplemented with more detailed self-administered tests. Other biological specimens and a hydroponic farm for growing plants were carried and used in experiments. Work related to Earth resources and weather was extensive. Detailed astronomical work began about midway through the mission, although various radiation studies had been conducted earlier. Ship systems and instrumentation got considerable testing.

When looking at the table of daily activities, an intriguing change in the routine occurs on June 17. The Soviet press gave no reports of scientific work or television transmissions, but only mentioned minor correction work", adding that the ship was equipped with tools, spare parts and safety devices. On June 18 the routine returned to normal, but G. E. Perry of the Kettering Grammar School in England detected telemetry transmissions on the Soyuz 11 frequency. This might have signaled that the trouble of the day before was forcing an early return, but the mission continued.

On June 29 the crew prepared for return to Earth, loading scientific specimens, films, tapes and other gear aboard Soyuz 11. The ships undocked at 1828 GMT and retrofire occurred at 2234 GMT. The normal follow-on routines of casting off the work compartment and service module were carried out prior to entering the dense atmosphere. Under its automatic systems, the ship oriented itself and steered to the intended recovery area. Radio communication with the crew came to an abrupt end at the moment of separating the work compartment, probably at 2247 GMT, even before the normal ionospheric blackout. The drogue and main parachute systems functioned, and a normal landing was made at about 2317 GMT, giving a total flight duration for the men of 570:22 hours, and 383 orbits, including 18 prior to docking, 362 docked, and 3 after undocking.

Upon reaching the capsule, the recovery team was horrified to discover the three cosmonauts dead on their couches. Although the Russians did not release information concerning the cause of death for quite some time, in 1973 U.S. negotiators for the Apollo-Soyuz Test Project pressured them into releasing the first detailed explanation.

Soyuz is equipped with two valves that open for spacecraft descent venting, the first at about 5,300 meters, the second at about 4,350 meters. One of the valves failed as the work module separated from the descent module. It appears that venting took about 40-50 seconds to reach the point where the ship's atmosphere could no longer support life. The crew became aware of the problem both because they could hear the pressure leak, and because the discharge of the air resulted in a spacecraft attitude change, causing an automatic thruster to fire to compensate. The crew tried to close the leak with a crank apparatus, but was unable to do so before losing consciousness and subsequently died of pulmonary embolisms.

The deaths dealt a major blow to the Soviet space program, which entered a slowdown even in its unmanned practical applications for many months. Only late in the year did flights begin to pick up again.

References

1. SOVIET SPACE PROGRAMS, 1971-75, OVERVIEW, FACILITIES AND HARDWARE MANNED AND UNMANNED FLIGHT PROGRAMS, BIOASTRONAUTICS CIVIL AND MILITARY APPLICATIONS PROJECTIONS OF FUTURE PLANS, STAFF REPORT , THE COMMITTEE ON AERONAUTICAL AND SPACE .SCIENCES, UNITED STATES SENATE, BY THE SCIENCE POLICY RESEARCH DIVISION CONGRESSIONAL RESEARCH SERVICE, THE LIBRARY OF CONGRESS, VOLUME – I, AUGUST 30, 1976, GOVERNMENT PRINTING OFFICE, WASHINGTON : 1976.

4. Perry, G. E. Flight International, London , December 10, 1970 , p. 923.

5. "Saliout" devoile pour la premiere fois. Air et Cosmos, Paris, May 31, 1975.

6. "Salyut na Orbite, Moscow : Mashinostroyeniye, 1973, page 8.

7. Les Stations Orbitales "Soliout", Moscow : Mashinostroyeniye, 1975, page 14.

8. Clark , P. S, Journal of the British Astronomical Association, London , December 1973,