A characteristic of the development and operation of the first Salyut space station was continuous work under time pressure. It is true that the TsKBEM’s designers, disappointed by the failure of the lunar programmes, worked with great enthusiasm because DOS was new and of major significance to the prestige of the Soviet space programme. However, the deadlines were simply unrealistic. Although the Kremlin told the team not to hurry, they were well aware that Moscow wished the station to be launched and occupied as soon as possible.
The list of achievements during only 16 months is almost unbelievable:
• The station was designed, constructed, tested, modified and launched into space.
• All of the station’s equipment, including the sophisticated apparatus for the scientific programme, was developed, tested and installed.
• The entire flight programme was prepared, including the extremely complex mission control and data processing.
• Two Soyuz spacecraft were fitted with the new docking system for internal transfer to the station, and after the Soyuz 10 failure this was modified for Soyuz 11.
• One Proton and two Soyuz launch vehicles were constructed.
• Three crews (a total of nine cosmonauts) were trained in how to operate the station, and underwent numerous reassignments.
But owing to the unrelenting pressure of time, the designers and managers of the Soyuz 11 mission made numerous omissions and errors, repeating the same basic mistakes which led to the loss of Vladimir Komarov on Soyuz 1 in 1967. After only limited testing, and without attaining the standards required for a successful mission, they launched an inadequately prepared spacecraft with a crew who had expected to train for longer before flying, supported by a control team which was technically and operationally ill-prepared for such a complex mission. In assessing the tragic loss of the Soyuz 11 crew, it is necessary to recognise that it resulted both from technical factors such as the design of the spacecraft and its operating regime, and from the omissions and errors of people right across the programme – politicians, generals, managers, designers, controllers and cosmonauts.
Before closing this gloomy chapter, it is worth summarising all the factors that are known to have contributed in some way to the tragedy.
• Valve screw – The screws on the ventilation valves of the descent module had been insufficiently torqued. The automatic shutter used a ball which was held in its nest by the screw. But the screw on No. 1 valve was not fastened properly, and when the pyrotechnics fired to jettison the orbital module the ball was unseated from its nest. Shatalov, who wrote of the discovery of this problem, did not specify how the screws were torqued on the valves of the Soyuz 11 spacecraft. But it is reasonable to infer from the fact that the ball was unseated on valve No. 1 that the screw was insufficiently torqued. The fact that the screw on the automatic shutter of valve No. 2 remained in its nest implies that this one was torqued to a higher force. It can therefore be concluded that if the screw on valve No. 1 had been somewhat tighter then the tragedy would not have occurred.
• Positions of the manually operated shutters – During the preparation of the spacecraft at the cosmodrome the technicians changed the positions of the manually operated shutters on both valves, making them inconsistent with the onboard documentation. Second only to the loose screw, this is another key factor relating to the valves of Soyuz 11. It is also ironic that on the first occasion that an automatic shutter failed, the actual settings of the manually operated shutters were inconsistent with the onboard documentation. When the configuration of the valves was changed at Baykonur the technicians, as Yeliseyev has written, “did not pay special attention to this change” because the valves were identical. In fact, they seriously erred in setting the valves in accordance with the manufacturer’s specifications. The manufacturer had no knowledge of the onboard documentation. The job of the technicians was to set the hardware to the configuration required by the crew, who expected the valves to be set differently, and trained to operate them in case of landing on water. In assembling and testing the spacecraft at the cosmodrome it ought to have been understood that irrespective of how the valves were supplied, once installed in the spacecraft they had to be set according to the onboard documentation!
• Manually closing the valves – The construction of the valves required direct manual operation, which in turn meant that the cosmonaut had to unbuckle from his couch and stand up; the valves should have been able to be closed via the command panel.
• Closing time – The closing of the manually operated shutter was too time consuming. In ideal conditions it took at least 35 seconds, which, in view of the dire consequences of the failure of the automated part of the system, was much too long.
• The location of the valves – Valve No. 1’s position above the centre couch was very close to two explosive bolts, making it susceptible to damage from the shock that was propagated through the structure by the jettisoning of the orbital module.
• Valve malfunction – It cannot be proved from the technical documentation, but it is possible that errors were made in manufacturing the valves.
Soyuz life support:
• Risk assessment – Having decided that decompression was impossible, the designers of the spacecraft did not provide an efficient means of protecting against it. The TsKBEM neglected to conduct a full risk assessment of all the factors which could lead to the loss of the crew as a result of not wearing pressure suits. This was done only after the Soyuz 11 tragedy.
• Automation – As on all previous Soviet spacecraft, Soyuz was designed to have the maximum of automation. For example, all landing operations were fully automated and did not require the involvement of the crew. On the one hand this enabled the craft to be flown unmanned; on the other, this made it difficult for a crew to intervene – as was demonstrated when Soyuz 10 was unable to dock with Salyut, and the resulting decision to modify that system for Soyuz 11 to give that crew a degree of control over the docking process. However, as Soyuz 11 demonstrated, the great mistake was to minimise the role of the crew in operating the most important of the vehicle’s systems – the life support system.
• Openings on the descent module – The descent module had three openings of critical importance for its hermetic seal. Two valves with tubes, each with a diameter of about 2 cm, and the hatch at the top of the module which had a diameter of 60 cm.
• Pressure suits – There were no pressure suits to protect the cosmonauts in the event of a decompression.
• Oxygen masks – The crew were not even given simple oxygen masks of the type that deploy automatically if the pressure drops in a commercial airliner. The spacecraft had a loss-of-pressure alarm. If this had deployed masks, the cosmonauts may have been able to function for several minutes after a rapid decompression, which would have been more that sufficient time to shut the leaking valve.
• Air decompression tanks – Due to its severely limited volume, the descent module did not have its own air tanks, and could not have replenished the cabin in the event of decompression. But on the other hand, it was believed that the possibility of decompression had been designed out.
• Inspection of the valves on the previous Soyuz descent modules – It was not the practice of the specialists at the TsKBEM to inspect the state of the valves on a descent module after its mission. If they had done so they would have noted the varying degrees to which the screws of the valves were being torqued during assembly.
• Explosive bolts – The explosive bolts were installed on the connecting ring that incorporated the hatch, which was another part of the descent module which was of critical importance for the crew safety. Westerners speculated that the twelve bolts were supposed to have fired in sequence, but for some reason went off simultaneously, thereby generating an intense shock which forced open the valve. However, the bolts were on the same electric circuit and were meant to fire simultaneously. The shock from their detonation was the same as on previous missions, but the valve was not. Based on all of the available sources related to the technical factors which caused the premature opening of the valve, it is possible to conclude that the main technical cause was its inappropriate assembly, possibly aggravated by a manufacturing fault.
• Organisation – The organisation of the Soyuz 11 mission was one of the weakest links in the chain of factors leading to the tragedy. The spacecraft was modified and tested much too hastily. The programme for the mission and the organisation of the crew’s activities were also developed in a hurry, and without full consideration of the implications of a prolonged exposure to weightlessness. For Mishin, who was antagonistic to the DOS programme, the main event in June 1971 was the third launch of the N1 lunar rocket. It was to oversee this that immediately after the docking of Soyuz 11 with the Salyut station he reassigned the flight directors. Kamanin and Chertok had only praise for Yeliseyev, but his nomination as the new flight director for the Soyuz 11 mission whilst it was underway was strange. In addition, the difficulty in coordinating the tracking ships in the final phase of the flight is further evidence that there were gaps in the organisation.
• The technical documentation – After the return of Soyuz 10, the revisions to the docking system were made within a month. Due to the tight schedule, Soyuz 11 was launched with onboard documentation and instruction which was inconsistent with the true situation – in particular, the manual shutters of the ventilation valves: No. 1 was ‘closed-open’ instead of‘closed-closed’, and No. 2 was ‘closed-closed’ instead of ‘closed-open’. Consequently, when the cosmonauts realised that a valve was leaking and went by the onboard documentation they wasted valuable time trying to close a valve which was already closed, while one that they thought was closed was actually leaking.
• Carelessness – The controllers at the TsUP knew the valves in the descent module were not as specified by the onboard documentation, but appear to have forgotten to inform the cosmonauts during the preparations to return to Earth.
• Inspections – There were gaps in the organisation of the inspection of the spacecraft’s systems before undocking from Salyut. This was mainly left to the crew, who were exhausted after the longest space mission in history. In addition, the coordination between the TsUP and spacecraft was aggravated by the briefness of the periods of radio communications.
• Hastiness – When a problem developed with the hatch during preparations to undock from Salyut, the TsUP failed to halt the proceedings. Instead of pausing to investigate the problem, the controllers improvised to circumvent the issue with a strip of insulating tape! The problem with the hatch was the warning bell that no one heard. The flight director should have intervened to review with his controllers the status of the life support system, and had the crew repeat the setup of the vital life support elements of the descent module – the ventilation valves as well as the hatch. With the spacecraft docked at the station, time was on their side.
• Crew teamwork – With a new commander assigned less than four months prior to the mission, Dobrovolskiy, Volkov and Patsayev were members of the third crew until the launch of Soyuz 10 in late April 1971. They had not trained as intensively as the first two crews. Yevgeniy Bashkin, who was an instructor, says that this crew was not given the same attention as the others, since no one expected them to fly to DOS-1. Cosmonaut Gorbatko even said that the majority of the TsPK staff did not recall seeing Patsayev during all his months of training! In addition, after the failure of Soyuz 10 to dock, the crew which expected to fly Soyuz 11 – Leonov, Kubasov and Kolodin – lost about one month of their training time when the launch was advanced from the middle of July to early June. They had only one month to train with the revised docking procedure, and the TsPK staff concentrated on this activity. Dobrovolskiy, Volkov and Patsayev, who became backups after the failure of Soyuz 10, trained in the shadow of the prime crew. But a few days prior to the launch they found themselves assigned the flight.
• Decompression training – In the training programme there was no basic cosmonaut decompression training.
• Differences in training procedures – The prime and backup crews for the Soyuz 11 mission trained using different re-entry procedures! Contrary to the training regulations, Leonov trained with the manually operated shutters of both ventilation valves closed during the descent. Dobrovolskiy trained according the rules, with one manually operated shutter open and the other closed.
• Wrong valve – Owing to the error in the onboard documentation and the fact that the flight controllers neglected to warn them otherwise, the crew of Soyuz 11 undocked from Salyut believing that the manual shutters of the ventilation valves were set in the opposite sense to that which was the case, and when they realised that a valve was leaking they directed their attention to the wrong one.
• Dobrovolskiy and Patsayev – As the two valves were located above their seats, Dobrovolskiy and Patsayev were involved in the emergency action.
• Volkov – Feoktistov has argued that Volkov, being the flight engineer, was responsible for the onboard systems, and that he failed to conduct a proper inspection of the valves – he could have detected the difference between the onboard documentation and the actual settings of the valves. An important question is what the cosmonauts should have done if Volkov had noted that the valves were set differently? Should he have closed No. 1 and opened No. 2 according the onboard documentation? It would have been logical to tell the TsUP about the difference, and let the flight director decide on the action. Would the fight director order Volkov to leave the valves as they were, or to adjust them to match the onboard documentation? Here is one of the key points concerning the actions of the crew. During his checks, Volkov ought to have discovered that the valves were set differently to the specification in the onboard documentation, but he didn’t. If he had, and had reset the state of the manually operated shutters to the onboard documentation, with No. 1 closed and No. 2 open, then when the automatic shutter on No. 1 became unseated there would not have been a decompression.
• Leonov’s advice – Dobrovolskiy did not accept Leonov’s intuitive advice in preparing for the descent. If the crew had disregarded what was specified in their instructions and had closed the manually operated shutters in both of the valves, when the shock wave from the explosive bolts firing opened the automated shutter of valve No. 1 this could not have led to a decompression. (It is ironic that if this had been done, the lax post-flight inspection routine would probably never have revealed just how close to disaster the Soyuz 11 crew had come!)
• A finger on the valve – Could the Soyuz 11 crew have done more to save their lives? Might Dobrovolskiy or Patsayev have been able to stem the air leak by placing a finger over the valve inlet whose aperture was no larger than a coin. Although Kamanin and the medics said no, Mishin persistently claimed that this could have been done! Could a cosmonaut survive with a part of his skin in direct contact with space? NASA has had one experience of a suit puncture. During a spacewalk on Shuttle mission STS-37 the palm restraint in an astronaut’s glove came loose and migrated until it punched a 1/8-inch hole in the pressure bladder between his thumb and forefinger. He did not realise that his suit had developed a puncture until after he was back inside the spacecraft and discovered a painful red mark on his hand. There had not been a decompression because when the metal bar holed the glove his hand spanned the opening, he bled into space, and the coagulating blood sealed the opening and served to ‘glue’ the bar in the hole, sealing it again.
• Slower reaction – The fatigue and disorientation of the Soyuz 11 crew after 24 days in space, together with the inadequate organisation of the flight, the tensions with the TsUP, the anxiety of the fire, and the difficulty closing the hatch all probably served to slow the reaction time of the cosmonauts during the rapid decompression.
Taken together, all of these factors led – directly and indirectly – to the deaths of the Soyuz 11 cosmonauts.
Although it is frowned upon to discuss the offenders, even although most of them are now dead, this remains a fundamental question. The people who knew that their actions or inactions contributed to the deaths of the cosmonauts had to live with this knowledge. Contrary to expectation, the Kremlin did not issue severe punishments, perhaps because the principal offenders included people from outside the TsKBEM who, against Kamanin’s protests, supported the decision to eliminate pressure suits. The most senior manager punished was Pavel Tsybin, a Deputy Chief Designer who worked for Feoktistov on the development of the transport version of the Soyuz. As after the Soyuz 1 disaster, therefore, the principal blame was assigned to a man who had no direct responsibility for the root cause of the problem. The decision for the crew of a Soyuz ship to fly without pressure suits was made many years earlier. The motivation to have a crew of three was probably to match the Apollo spacecraft that was being developed by the Americans. The concept of the spacecraft was for three modules, with the descent module in the middle. The small size of the capsule required the cosmonauts to fly without pressure suits. Interestingly, when Dmitriy Kozlov, the Chief Designer of Branch No. 3 of OKB-1, revised the design of the spacecraft for use by the military, he reduced the crew to two cosmonauts wearing pressure suits. But Mishin, with the support of Afanasyev (and obviously Ustinov), stopped this project and thereby ended any chance of radically revising the basic concept of the Soyuz spacecraft. But this early work was not lost, and when Bushuyev recommended a detailed redesign of the spacecraft in the wake of the Soyuz 11 tragedy, some of Kozlov’s arguments were reconsidered and accepted.
Although Soyuz was built as a cooperative project with numerous design bureaus and civilian and military structures, the TsKBEM was in charge. The TsKBEM was responsible for all technical aspects of the spacecraft, and also for the organisation and technical control of a flight. So people from the TsKBEM must be at the top of the list of offenders. First is the Chief Designer, Vasiliy Mishin. Then Konstantin Bushuyev, his deputy for manned spacecraft. Then the Soyuz design team headed by Konstantin Feoktistov. Then the managers led by Yevgeniy Shabarov, who were responsible for assembling and testing the Soyuz apparatus. They neglected to test the torque on the screws of the automated ventilation valves, and made changes to the positions of the manually operated shutters. Even if a valve had a technical malfunction, the TsKBEM was responsible for detecting this and, in coordination with the manufacturer, fixing it. On the list must also be the people who were responsible for post-flight assessment of the descent module’s apparatus (which would have revealed the earlier problems with the screws in the ventilation valves); those who tested procedures and managed the technical documentation for the cosmonauts; and the mission controllers led by Yakov Tregub and his assistant Aleksey Yeliseyev.
Are there other offenders outside the TsKBEM? The decompression training that Mishin highlighted is an issue for discussion. Decompression was not included in the training, largely because the descent module was believed not to be susceptible to decompression. But the question was what three men squeezed in the cramped descent module could do in the way of training for such an event? What would be the standard procedure for a period as brief as 13 seconds? Were they supposed to stand up and (as Mishin said) block the valve using a finger? They clearly trained to cycle the manually operated shutters after landing in water. Perhaps they could have been trained to rapidly find the source of a decompression, and to work as a team in such a situation. But how could they have closed a shutter in a mere 13 seconds during an emergency which took at least 35 seconds to shut in ideal circumstances? There was no technical support (such as automatically deployed oxygen masks) to enable a crew to survive decompression long enough to close the valve, and even if they managed this there was no reserve air tank to replenish the cabin! Training was the responsibility of Generals Kamanin and Kuznetsov and, as the main critic of the decision to dispense with pressure suits, perhaps Kamanin should have been more insistent that measures be taken to enable a crew to survive a decompression.
But the most significant omission in the training of the cosmonauts was related to the safest management of the ventilation valves. If both valves had been operated in the ‘closed-closed’ mode, the Soyuz 11 crew would not have died! Contrary to the specification in the training and flight instruction, Leonov’s crew were trained with this mode. The fact that Dobrovolskiy’s crew were trained to operate differently is not their omission, it is that of the trainers at the TsPK.
In addition to all these technical and managerial problems related to the Soyuz 11 mission, there is still the question of whether the cosmonauts could have done more to survive. Their actions can be analysed in relation to operations before and during re-entry/decompression. What could they have done before re-entry? While docked with Salyut, the crew performed a detailed inspection of the spacecraft’s systems by referring to the onboard technical documentation. Here is the first point where the coordination between the TsUP and the crew faltered. The controllers failed to point out that the onboard documentation was incorrect. The crew inspected the valves, but failed to realise the differences between their true status and that in the onboard documentation. As noted, if they had reset the valves to match their documentation, there would have been no decompression. During the checking procedure prior to undocking from the station, Leonov advised that they close both valves and reopen one once the parachute had deployed, but the crew followed their flight instruction. From their point of view, this was reasonable – it was the way that they had trained.
During the decompression the cosmonauts attempted such actions as they could in an effort to halt the leak, but (in view of all the technical limitations in the descent module listed above) they did not have a realistic chance. First, they lost valuable seconds inspecting the hatch seal. Upon realising that the air was leaking from one of the ventilation valves, they attempted to close the manually operated shutter of valve No. 2, which they believed was open but in reality was closed. In desperation, they turned to valve No. 1, which was supposed to be closed, and found that it was actually open! Yeliseyev said they should have worked as a team, and closed both of the valves simultaneously. But even if they had not wasted time on the hatch, and Dobrovolskiy and Patsayev had each moved to close one manually operated shutter, the 13 seconds available before they were rendered ineffective was insufficient to have completed the task – without prior planning and some technical assistance, they had stood no chance of saving themselves.
1. Kamanin, N. P., Hidden Space, Book 4. Novosti kosmonavtiki, 2001, pp. 338340 (in Russian).
2. Chertok, B. Y., Rockets and People – The Moon Race, Book 4. Mashinostrenie, Moscow, 2002, pp. 341-348 (in Russian).
3. Salahutdinov, G. M., ‘Once More about Space’. Aganyok, No. 34, 1990 (Interview with Vasiliy Mishin).
4. Tarasov, A., ‘Missions in dreams and Reality’. Pravda, 20 October 1989 (Interview with Vasiliy Mishin).
5. Yeliseyev, A. S., Life – A Drop in the Sea. ID Aviatsiya and kosmonavtika, Moscow, 1998, p. 82 (in Russian).
6. Novosti kosmonavtiki (in Russian)
No. 4, 2002 (Interview with Vladimir Shatalov)
No. 3, 2005 (Interview with Valeriy Kubasov)
7. Scott, David and Leonov, Alexei, Two Sides of the Moon – Our Story of the Cold War Space Race. Simon & Schuster, 2004, pp. 263-265.
8. Afanasyev, I. B., Baturin, Y. M. and Belozerskiy, A. G., The World Manned Cosmonautics. RTSoft, Moscow, 2005, p. 230 (in Russian).
9. ‘Cosmonauts died because valve was forced open’, The Washington Post, 29 October 1973.
10. Email from Svetlana Patsayeva with materials from Vera Patsayeva, 1 August 2007.
11. Email from David M. Harland, 13 November 2006, ‘Soyuz-11 and the silence of the cosmonauts’.
12. Raketno-Kosmicheskaya Korporatsiya ENERGIYA imeni S. P. Koroleva (RKK Energiya: The aerospace corporation named after S. P. Korolev) 1946-1996 (in Russian).