.png) Soyuz 11 on a 1971 commemorative stamp of theSoviet Union | |
| Mission type | Dock withSalyut 1 |
|---|---|
| Operator | Soviet space program |
| COSPAR ID | 1971-053A |
| SATCATno. | 05283 |
| Mission duration | 23 days, 18 hours, 21 minutes, 43 seconds |
| Orbits completed | 383 |
| Spacecraft properties | |
| Spacecraft | Soyuz, 7K-T No. 32[1] |
| Spacecraft type | Soyuz 7K-OKS |
| Manufacturer | OKB-1 |
| Launch mass | 6,565 kg (14,473 lb)[2] |
| Landing mass | 1,200 kg (2,600 lb) |
| Crew | |
| Crew size | 3 |
| Members | |
| Callsign | Янтарь (Yantar – "Amber") |
| Start of mission | |
| Launch date | 04:55:09, 6 June 1971 (UTC) (1971-06-06T04:55:09Z) |
| Rocket | Soyuz |
| Launch site | Baikonur,Site 1/5[3] |
| End of mission | |
| Landing date | 23:16:52, 29 June 1971 (UTC) (1971-06-29T23:16:52Z) |
| Landing site | 90 km (56 mi) southwest ofKarazhal,Karaganda Oblast,Kazakh SSR,Soviet Union (47°21′23″N70°07′16″E / 47.35639°N 70.12111°E /47.35639; 70.12111) |
| Orbital parameters | |
| Reference system | Geocentric orbit[4] |
| Regime | Low Earth orbit |
| Perigee altitude | 185 km (100 nmi; 115 mi) |
| Apogee altitude | 217 km (117 nmi; 135 mi) |
| Inclination | 51.6° |
| Period | 88.3 minutes |
| Docking withSalyut 1 | |
| Docking date | 7 June 1971 |
| Undocking date | 29 June 1971, 18:28 UTC[2] |
| Time docked | 22 days |
 Zvezda Rocket  Left to right:Dobrovolsky,Volkov andPatsayev | |
Soyuz 11 (Russian:Союз 11,lit. 'Union 11') was the only crewed mission to board the world's firstspace station,Salyut 1.[a][5] The crew,Georgy Dobrovolsky,Vladislav Volkov, andViktor Patsayev,[6][7][8] arrived at the space station on 7 June 1971, and departed on 29 June 1971. The mission ended in disaster when thecrew capsuledepressurised during preparations forre-entry, killing the three-person crew.[9] The three crew members of Soyuz 11 are the onlyhumans to have died in space.[b][10]
| Position | Cosmonaut | |
|---|---|---|
| Commander | Georgy Dobrovolsky Only spaceflight | |
| Flight engineer | Vladislav Volkov Second and last spaceflight | |
| Research engineer[2] | Viktor Patsayev Only spaceflight | |
| Position | Cosmonaut | |
|---|---|---|
| Commander | Aleksei Gubarev | |
| Flight engineer | Vitaly Sevastyanov | |
| Research engineer | Anatoly Voronov | |
| Position | Cosmonaut | |
|---|---|---|
| Commander | Alexei Leonov | |
| Flight engineer | Valery Kubasov | |
| Research engineer | Pyotr Kolodin | |
The original prime crew for Soyuz 11 consisted ofAlexei Leonov,Valery Kubasov, andPyotr Kolodin. A medicalX-ray examination four days before launch suggested that Kubasov might havetuberculosis, and according to the mission rules, the prime crew was replaced with the backup crew.[11] For Dobrovolsky and Patsayev, this was to be their first space mission. After the failure ofSalyut 2 to orbit, Kubasov and Leonov were reassigned toSoyuz 19 for theApollo-Soyuz Test Project in 1975.[citation needed]
TheSoyuz 7K-OKS spacecraft was launched on 6 June 1971, from theBaikonur Cosmodrome in the centralKazakh Soviet Socialist Republic, and used the callsignYantar (Amber).[13] Several months earlier, the first mission to the Salyut,Soyuz 10, had failed to successfully dock with the station.[14] During the first day of the flight, maneuvers were made to effect arendezvous with the uncrewed Salyut (1971-032A). When Soyuz 11 was 6 to 7 kilometres (3.7 to 4.3 mi; 3.2 to 3.8 nmi) from Salyut, automatic devices took over, and in 24 minutes closed the gap between the two ships to 9 metres (30 ft) and reduced the relative speed difference to 0.2 metres per second (0.66 ft/s). Control of the ships went from automatic back to manual at 100 metres (330 ft). Docking took 3 hours 19 minutes to complete and involved making the connection mechanically rigid, engaging various electrical and hydraulic links, and establishing air-tight seals before locks could be opened. When the pressure was equalized between the ships, the locks were opened and all three members of the crew passed into Salyut 1.[2] Soyuz 11 successfully docked with Salyut 1 on 7 June 1971 and the cosmonauts remained on board for 22 days, setting space endurance records that would hold until the AmericanSkylab 2 mission in May and June 1973.[9]
Upon first entering the station, the crew encountered a smoky and burnt atmosphere, and after replacing part of the ventilation system, spent the next day back in their Soyuz until the air cleared. Their stay in Salyut was productive, including live television broadcasts. A fire broke out on day 11 of their stay, causing mission planners to consider abandoning the station. The planned highlight of the mission was to have been the observation of anN1 rocket launch, but the launch was postponed.[1] The crew also found that using the exercise treadmill, as they were required to twice a day, caused the whole station to vibrate.[1]Pravda released news of the mission and regular updates while it was in progress.[citation needed]
On 29 June 1971, the three cosmonauts loaded scientific specimens, films, tapes, and other gear into Soyuz 11, then transferred manual control back from Salyut 1 to Soyuz 11 and returned to their ferry craft, with undocking occurring at 18:28 GMT. Soyuz 11 flew co-orbit for a while before it retro-fired at 22:35 GMT in preparation for re-entry. Before re-entering Earth's atmosphere, both the work compartment and the service module were jettisoned. This occurred at about 22:47 GMT. Radio communications abruptly ended when the work compartment separated, well before the normal ionospheric blackout.
Almost 25 minutes later, Soyuz 11's automatic systems landed the craft at 23:16:52 GMT, 90 kilometres (56 mi; 49 nmi) southwest ofKarazhal inKazakhstan, after an abnormally silentreturn to Earth. The total flight duration of the crew had been 570.22 hours and involved 383 orbits—18 prior to docking, 362 docked, and three after undocking. When the recovery team opened the capsule of the Soyuz 11, they found all three men dead.[9][15][16]
Kerim Kerimov, chair of the State Commission, recalled: "Outwardly, there was no damage whatsoever. They knocked on the side, but there was no response from within. On opening the hatch, they found all three men in their couches, motionless, with dark-blue patches on their faces and trails of blood from their noses and ears. They removed them from the descent module. Dobrovolsky was still warm. The doctors gave artificial respiration. Based on their reports, the cause of death was suffocation".[17]
It quickly became apparent that the cosmonauts hadasphyxiated. The fault was traced to a breathing ventilation valve, located between the orbital module and thedescent module, that had been jolted open as the descent module separated from theservice module, 12 minutes and 3 seconds after retrofire.[18][19] The two modules were held together byexplosive bolts designed to fire sequentially; in fact, they had fired simultaneously.[18] The explosive force of the simultaneous bolt firing caused the internal mechanism of the pressure equalisation valve to loosen a seal that was usually discarded later and which normally allowed for automatic adjustment of the cabin pressure.[18] The valve opened at an altitude of 168 kilometres (104 mi; 91 nmi), and the resultant loss of pressure wasfatal in less than a minute.[18][20] The valve was located beneath the seats and was impossible to find and block before the air was lost. Flight recorder data from the single cosmonaut outfitted with biomedical sensors showed cardiac arrest occurred within 40 seconds of pressure loss. By 15 minutes 35 seconds after retrofire, the cabin pressure was zero, and remained there until the capsule entered theEarth's atmosphere.[18] Patsayev's body was found positioned near the valve, and he may have been attempting to close or block the valve at the time he lost consciousness. An extensive investigation was conducted to study all components and systems of Soyuz 11 that could have caused the accident, although doctors quickly concluded that the cosmonauts had died of asphyxiation.[18]
The autopsies atBurdenko Main Military Clinical Hospital found that the cause of death for the cosmonauts washaemorrhaging of the blood vessels in their brains, with lesser amounts of bleeding under their skin, in their inner ears, and in their nasal cavities, all of which occurred as exposure to a vacuum environment caused the oxygen and nitrogen in their bloodstreams to bubble and rupture vessels. Their blood was also found to contain heavy concentrations oflactic acid; lactic acid buildup (in tissues and blood) is a sign of inadequate mitochondrial oxygenation, which may be due tohypoxemia (low blood oxygen), poor blood flow (e.g., decompression) or a combination of both. Although they could have remained conscious for almost 40 seconds after decompression began, less than 20 seconds would have passed before the effects of oxygen starvation made it impossible for them to function.[17]
Alexei Leonov, who would have originally commanded Soyuz 11, had advised the cosmonauts before the flight that they should manually close the valves between the orbital and descent modules, as he did not trust them to shut automatically, a procedure he thought up during extensive time in the Soyuz simulator. However, it appears that the crew did not do this. After the flight, Leonov went back and tried closing one of the valves himself, and found that it took nearly a minute to do so, too long in an emergency situation with the spacecraft's atmosphere escaping fast.[17]
The Soviet state media attempted to downplay the tragic end of the mission, and instead emphasized its accomplishments during the crew's stay aboard Salyut 1. Since they did not publicly announce the exact cause of the cosmonauts' deaths for almost two years afterwards, United States space planners were extremely worried about the upcomingSkylab program, as they could not be certain whether prolonged time in amicro-g environment had turned out to be fatal. However, NASA doctorCharles Berry maintained a firm conviction that the cosmonauts could not have died from spending too many weeks in weightlessness. Until the Soviets finally disclosed what had really happened, Berry theorized that the crew had died from inhaling toxic substances.[17]
A film that was later declassified showed support crews attemptingcardiopulmonary resuscitation (CPR) on the cosmonauts.[21][c] Untilautopsy, they were not known to have died because of a capsule depressurisation. The ground crew had lost audio contact with the crew before re-entry began, and had already begun preparations for contingencies in case the crew had been lost.[6]
The cosmonauts were given a largestate funeral and buried in theKremlin Wall Necropolis atRed Square,Moscow, near the remains ofYuri Gagarin.[9] They were also each posthumously awarded theHero of the Soviet Union medal.[17]
The United States sentTom Stafford, then NASA'sChief Astronaut, to represent PresidentRichard Nixon at the funeral, where the Soviets asked him to be one of thepallbearers. It came at the beginning of a period ofmore cordial relations between the two nations that would lead to the jointApollo–Soyuz mission.[17] President Nixon also issued an official statement following the accident:[15]
The American people join in expressing to you and the Soviet people our deepest sympathy on the tragic deaths of the three Soviet cosmonauts. The whole world followed the exploits of these courageous explorers of the unknown and shares the anguish of their tragedy. But the achievements of cosmonauts Dobrovolsky, Volkov and Patsayev remain. It will, I am sure, prove to have contributed greatly to the further achievements of the Soviet program for the exploration of space and thus to the widening of man's horizons.
TheSoyuzspacecraft was extensively redesigned after this incident to carry only two cosmonauts. The extra room meant that the crew could wearSokol space suits during launch and landing. The Sokol was a lightweight pressure suit intended for emergency use; updated versions of the suit remain in use.[17]
The Soyuz 11 landed 90 kilometres (56 mi; 49 nmi) south-west ofKarazhal,Karagandy,Kazakhstan, and about 550 kilometres (340 mi; 300 nmi) north-east ofBaikonur. A memorial monument in the form of a three-sided metallic column, with the engraved image of the face of each crew member set into a stylized triangle on each of the three sides, was placed at the site. The memorial is in open, flat country, far from any populated area, within a small, circular fence.[22]
In 2012, the memorial was found to have been vandalized beyond repair, with only the base of the metallic column remaining and any roads leading to it overgrown.[23]
In 2013, Russian space agencyRoscosmos restored the site with a redesigned monument, reflecting the three-sided form of the original, but this time constructed from brick. Also placed at the site was a sign explaining the history of the location and the fate of the original monument.[24]
Craters on the Moon werenamed after the three cosmonauts:Dobrovolʹskiy,Volkov, andPatsaev. The names of the three cosmonauts are included on theFallen Astronaut commemorative plaque placed on the Moon during theApollo 15 mission in August 1971. To honour the loss of the Soyuz 11 crew, a group of hills onPluto is also namedSoyuz Colles.[citation needed]
In the city ofPenza, Russia, near the school gymnasium No. 39, in honour of the dead cosmonauts, a memorialstele was made with quotes from the poem by the poetYevgeny Yevtushenko "Between our Motherland and you is a two-way eternal connection" (Russian:"Между Родиной нашей и вами – двусторонняя вечная связь").[25]
In addition to the Soviet postage stamp depicted above, a series of postage stamps of theEmirate of Ajman[26] andBulgaria[27] was issued in memory of the cosmonauts in 1971.Equatorial Guinea also released a series of stamps depicting the entire Soyuz 11 mission.[28]
This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain.
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| Past missions (by spacecraft type) |
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Uncrewed missions are designated asKosmos instead ofSoyuz; exceptions are noted "(uncrewed)". The † sign designates failed missions.Italics designates cancelled missions. | |||||||||||||||||||||||||||
