Dobrovolskiy, Volkov and Patsayev knew well the risks of the return operation, but on the third orbit after undocking from Salyut they were in excellent spirits and impatient for the landing. At 1.10 a. m. on Wednesday, 30 June, while out of radio contact over the Pacific Ocean approaching Chile, Dobrovolskiy, assisted by Volkov, oriented Soyuz 11 to position its main engine facing the direction of the flight.
One of many disputed issues concerning the final phase of this mission is the time of the last words from the crew.
The last officially published communication from Soyuz 11 was at 00.16 a. m., when Kamanin in the TsUP spoke to Dobrovolskiy, who reported that they were in the process of preparing for the orientation manoeuvre. At that time they could still see the Salyut station. Then the controller signed off with: “Good-bye Yantars, until the next communication session.”
The official sources do not give a chronology of the last conversations with the Soyuz 11 crew, or between the cosmonauts.
In his 1971 book Soviets in Space, Peter Smolders cites the following words from Dobrovolskiy as the last communication received by the TsUP: “I am beginning the descent procedure.”
Yeliseyev’s book offers the following account of the final words received by the TsUP: “The last communication session is ending. Immediately before leaving the zone of radio visibility, Volkov managed to call loudly to say: ‘Prepare cognac, see you tomorrow!’ …” However, owing to the phrase “see you tomorrow” the time of this reported communication is unclear – was it on 29 June or 30 June. Nevertheless, the words “Prepare cognac” would be a typical final message prior to an imminent reunion. It may well have been that immediately before the loss of communication Dobrovolskiy said he was “beginning the orientation” and then in the final seconds Volkov managed to add his remark.
Between 1.22.00 a. m. and 1.31.25 a. m. Soyuz 11 passed over South America and then set off across the Atlantic Ocean. As noted, for optimal visibility at the landing site the braking manoeuvre was to be made on the third orbit after undocking from the station. This was why Soyuz 11 had a different re-entry trajectory than previous missions. One circuit of the Earth lasted on average 89 minutes. During this interval the planet rotated through 22.2 degrees, so Soyuz 11 was north of the equator at the moment that the engine fired, somewhat to the north and west of the typical braking position for a Soyuz descent. The engine was fired automatically at 1.35.24 a. m., as planned. At that time, Soyuz 11 was over the Atlantic between the northeast coast of South America and the coast of Africa. The engine fired for the planned duration of 187 seconds and was automatically switched off after reducing the speed of the spacecraft by the requisite 120 m/s. Another interesting detail – in contrast to most of the previous flights, in this case the braking manoeuvre was made during the descending portion of the orbit – i. e. after the ship had passed the apogee point. Following the braking manoeuvre, the automated control system would reorient the vehicle for the separation of the modules, perform the separation, control the path of the descent module through the atmosphere in order to aim for the target, manage the parachute deployment sequence, jettison the heat shield, fire the retro-rockets and jettison the parachute. The crew were not required to participate in any of these critical operations.
Did the tracking ships in the Atlantic Ocean detect signals from Soyuz 11 during the braking manoeuvre? Chertok’s memoirs and Kamanin’s diary, two of the most widely cited sources, offer contrary accounts.
After undocking from the station, two orbits are allowed to prepare for the descent. The crew will conduct manual orientation while out of our visibility
Soyuz ll’s descent track. (Courtesy Sven Grahn)
zone and pass control to the gyro instruments. The command for the start of the descent activity will be emitted from NIP-16, with NIP-15 as the reserve. The KTDU will fire for braking at 1 hour 47 minutes on 30 June. …
All indications on the panel were normal, and the cosmonauts reported the achievement of all operations on time. … Everything went according to the timetable. The tracking ships received information as the spacecraft passed above, and reported to the TsUP that the braking engine had operated for the estimated duration and was switched off by the integrator [when the correct velocity had been attained]. The control-measuring complex and the GOGU were satisfied with the control of the spacecraft on the landing orbit.
After engine cut-off, the spacecraft exited the communication zone of the tracking ships in the Atlantic. The orbital module and the propulsion module were jettisoned from the descent module while passing over Africa.
Based on this, we can conclude that the TsUP had information from “the tracking ships” that the braking engine was fired and shut off as expected, and that Soyuz 11 then re-entered as planned. Also, Chertok implies that several ships were involved in tracking this particular re-entry! Furthermore, he said that Soyuz 11 left the radio zone of the ships when the main engine switched off, which is a point also made by the official TASS report (see the next chapter). However, he was mistaken in giving the time of the braking manoeuvre as 1.47 a. m. (this was the time that the modules were separated) and incorrect in saying that the separation occurred above Africa (it was the typical scenario for the previous Soyuz missions, but not in this case).
Another author, Colonel Ivan Borisenko, the ‘Sporting Commissar’, has said that communication was briefly established with Soyuz 11 about this time, then lost at the moment of the separation of the modules.
However, in his diary entry of 30 June General Kamanin says:
According to the re-entry programme, the KTDU must start at 01.35.24 and should turn off after 187 seconds. We impatiently waited for a report of the braking manoeuvre. Shatalov repeatedly called Yantar on line, but there was no response from the crew. …
At 1.47.28 the separation must occur, … but there are no reports about this. We did not know whether Soyuz 11 had begun the descent, or had remained in orbit. The period of communication calculated for the case of the ship not leaving orbit (01.49.37-02.04.07) began. There was an oppressive silence in the room. There was no communication with the crew or any new data about Soyuz 11. Everyone understood that something had occurred aboard the spacecraft, but no one knew what. The minutes of expectation passed terribly slowly.
So, according to Kamanin, no one in the TsUP knew whether the main engine had fired on time or if the braking manoeuvre had been completed. He did not mention receiving the information from the tracking ships in the Atlantic that Chertok cited. There was no response from the spacecraft to Shatalov’s calls. The silence from the spacecraft shortly before, during, and after the braking manoeuvre,
which was about ten minutes before the separation of the modules, is another interesting detail. With the exception of Kamanin, no other source (Chertok, Yeliseyev, Feoktistov, Rebrov, and others) spoke of the silence of the crew in the braking period – while Soyuz 11 was passing over the tracking ships. Yeliseyev, who was in the TsUP with Kamanin, Chertok, Feoktistov and others, did not refer to tension in the control room owing to uncertainty concerning the braking manoeuvre. He wrote nothing about the tracking ships and signals they might have received from Soyuz 11; only of data from the radar stations which detected the descent module after its path had carried it onto Soviet territory.
So what really happened? Let us consider the tracking ships in the Atlantic. Due to the position of Soyuz 11 during the braking manoeuvre, only a ship located in the equatorial region could have received a transmission during this time. Bezhitsa was at its operating station near the coast of Africa in the Gulf of Guinea, at 1.5 degrees south, 13 degrees west, until 29 June. From this station, it would have had two or three opportunities each day to monitor the success of the braking manoeuvre. But it had been at sea for four months, and was low on provisions. It was to sail to Las Palmas in the Canary Islands in early July for replenishment. Since this station was of crucial importance to monitoring Soyuz 11 during its braking manoeuvre, it was decided that Kegostrov, in the South Atlantic at 22 degrees south, 24 degrees west, should move to relieve Bezhitsa. On 29 June Bezhitsa received an unexpected order to leave its station. Amazingly, it left before Kegostrov arrived to replace it! On the morning of 30 June, local time, when it was realised that Kegostrov would not be in position before Soyuz ll’s braking manoeuvre, the head of the Soviet Naval Fleet personally ordered Bezhitsa’s captain to urgently return to his previous station so as to monitor the braking manoeuvre – not just the telemetry but also the commentary from the crew. However, it was apparent that Bezhitsa would not be able to resume its former station in time.
Why was Soyuz 11 allowed to proceed with the undocking and return to Earth if a tracking ship to monitor the braking manoeuvre was absent? As noted, in planning the mission there were discussions about whether it should be for 45, 30 or 25 days. Finally, guided by the ballistics, Mishin had decided to accept the ‘25’-day duration and shorten it by one day, with the landing on 30 June instead of 1 July. This is the first important detail to consider when pondering the reasons for Soyuz ll’s return without a tracking ship in this key position. It would appear that in the final stage of the mission the usually excellent co-ordination between the TsUP (in fact, the State Commission) and the Soviet Naval Fleet failed, causing Bezhitsa to leave its station prior to the arrival of Kegostrov. In addition, there had been a dispute between the Air Force (Kamanin) and the TsKBEM (Tregub) about whether Soyuz 11 should return on the second or the third orbit after it undocked from the station. A return on the second orbit would have taken the familiar route across Africa, but would have meant landing in darkness. During the additional orbit, the eastward rotation of the Earth displaced the longitude at which the spacecraft would perform its
The tracking ship Bezhitsa was unable to monitor Soyuz ll’s braking manoeuvre.
northward crossing of the equator 22 degrees to the west. The descent trajectory for Soyuz 11 was therefore different to the one with which everybody was familiar – as indicated by the mistake in Chertok’s account. Instead of firing the main engine while passing above the Gulf of Guinea, where Bezhitsa was to have been, the braking manoeuvre started at 10 degrees north, 40 degrees west, and was concluded at 29 degrees north, 32 degrees west. At Soyuz ll’s altitude, the communication zones of Bezhitsa and Kegostrov were about 15 degrees in radius, but beyond about 10 degrees the signal was weak. In fact, not only was Bezhitsa off-station when the spacecraft performed its braking manoeuvre, that fact that it was sailing at maximum speed in an effort to resume its station meant that it did not even attempt to listen. And Kegostrov, being even further away, could not have received a signal from Soyuz 11 at the vital time. This is why (as Kamanin noted) no one in the TsUP knew whether the spacecraft had made the manoeuvre. And, of course, even if one of these two ships had been in position, neither was equipped to relay the VHF transmission from the spacecraft to the TsUP, which is why the control room did not hear the cosmonauts’ voices, only “silence”. Academician Sergey Korolev and Cosmonaut Vladimir Komarov were equipped to relay signals from a spacecraft to the TsUP, but only when a Molniya satellite was conveniently positioned, and in this case Komarov was out of service and Korolev was in the North Atlantic and too far away to receive signals during the spacecraft’s braking manoeuvre.