Aftermath of the Soyuz docking mission
As engineers at the TsKBEM design bureau began painstaking sifting through the data from the complex joint mission of the 7K-OK spacecraft, the official Soviet process celebrated the success of the world's first automated docking, while trying keeping the lid on the design of the new space vehicle.
Engineers dig into the flight problems
After all the fanfares, on Nov. 11, 1967, at 10:00, Mishin opened a special meeting dedicated to the technical problems that had been revealed during the dual Soyuz mission. Evgeny Bashkin from Department 312, reported on the ongoing issues with the 45K star tracker and the ion attitude control system. He explained that the sunlight getting into the optical cupola created an effect resembling starlight, which confused sensors. To resolve the problem, engineers would need to drastically redesign the instrument, Bashkin said. He also reported that the ion system (which had guided the landing of Vehicle No. 5) signaled the permission for the firing of the SKD engine despite an unacceptable deviation of the spacecraft from its proper attitude. This problem apparently first manifested itself during the test firing of the engine, but was missed by mission control at the time.
Also, Boris Raushenbakh reported his analysis of the rendezvous dynamics. His team identified four serious problems during the linkup of the spacecraft. At a distance of around one or two kilometers between the two ships, the active vehicle made unnessary turnarounds, the Igla system displayed some fluctuations in its channels, its range finder was switching its scale system and three times the SKD engine failed to respond to the initial command of the flight control system to fire.
Fortunately, all these glitches had not prevented docking, however, Lev Vilnitsky then confirmed that the ships had remained around 85 millimeters apart, which he explained by the lack of clearance between the (secondary) drogues and their outlets on the opposite spacecraft under conditions when the two ports were under drastically different temperature conditions. Mishin noted that the docking port had to be certified to work within a temperature range from minus to plus 50C degrees. (774) However, the situation was probably complicated by the fact that during the actual docking, one port could be fully illuminated by the sun, while another could be in the complete or partial shadow of its host spacecraft.
Alternative scenario of docking problems
In his memoirs, docking expert Vladimir Syromyatnikov wrote that the rotation counter, ChOD, inside the docking mechanism displayed signs of sporadic fluctation during the berthing and its frequency matched the frequency of the ball fastener in the docking mechanism. Specialists in docking mechanics interpreted this phenomenon as a manifestation of some foreign object inside the docking mechanism. According to Syromyatnikov, the subsequent review of processing documents in Tyuratam revealed that during final preparations of the "active" Soyuz spacecraft, test operators had accidentally issued a command for the retraction of the drogue on the docking port. At the time, the docking port was covered with a protective plastic film, which was then sucked inside the docking mechanism by the retracting drogue.
When engineers noticed the problem, they cycled the drogue back and forth and concluded that the mechanism was unaffected. One specialist suggested conducting an additional test with telemetric recording of all the parameters of the mechanism's operation, but his colleagues urged him not to worry, arguing that there would be no actual docking during this mission.
From Syromyatnikov's memoirs, it appears that despite the docking mechanics engineers honestly reporting their findings up the chain of command, they received no reprimands, nor were they blamed for the docking failure. (201) Probably the upper management at TsKBEM, which had a much wider picture of the situation, found the team's self-indictement unconvincing and saw other culprits in the botched docking.
In the meantime, Viktor Legostaev, Mishin's deputy for flight control systems, reviewed the situation that had led one of the ships (probably Vehicle No. 6) to separate its modules at the end of the flight on a backup command from thermal sensors, as it was reentering the atmosphere, instead of relying on the primary flight control system. Legostaev reported (probably referring to the same Vehicle No. 6) that 18 seconds after the braking engine cutoff, the gyroscopes (of the attitude control system) stalled. It was apparently the result of a very sharp disturbance in the spacecraft orientation caused by air escaping from the habitation compartment via a special T-shaped valve. The planned depressurization of the habitation module was programmed to take place after the engine cutoff, however, apparently, the recoil effect of the depressurization on the attitude control system was not properly accounted for. Mishin proposed to consider depressurizing the module before the maneuver or leaving the habitation module pressurized until its separation from the descent capsule.
Yakov Tregub, who supervised mission control operations, summarized a total of eight failed attempts to transmit commands to the spacecaft, which constituted on an average 14-percent failure rate in the remote-control process. In one case, a human error at the NIP-16 ground station in Crimea was to blame, in two cases, technical problems were found to be culprits. (774)
On November 13, Mishin hosted another meeting dedicated to the ballistics of the flight. Various problems during orbit corrections and deorbiting maneuvers were apparently raised and there was a discussion of the possibility of determining the area where Vehicle No. 5 blew up.
On the same day, the meeting of the Chief Designer Council also reviewed the flight. Armen Mnatsakanyan reported on the operation of the rendezvous system and promised to present by November 20 a full scope of the planned upgrade work, which was to be completed in a month or two.
In a meantime, Igor Yurasov and his associates Zvorykin and Bogomolov took charge of the investigation into the abnormal switching on and off of the SKD engine during the rendezvous.
Desinformation campaign around Kosmos-186/188
In the tradition of Soviet secrecy, the successfull docking of Soyuz spacecraft was followed by a peculiar desinformation campaign. In the official coverage of the high-profile flight, the Soviet press began consistently publishing fake depictions of the two spacecraft performing the pioneering docking. The spacecraft were also called "satellites" rather than being described as "spaceships" as was customary for reports about manned vehicles.
It was a clear effort to hide the fact that Kosmos-186 and Kosmos-188 had actually been Soyuz 7K-OK spacecraft, but long after the truth came out, these pictures remained a source of confusion.
In 1985, an official Soviet publication finally identified Kosmos-186 and Kosmos-188 as unmanned Soyuz spacecraft, but, until today, the visuals from the original disinformation campaign occasionally surface to "illustrate" the story of the world's first automated docking in space.
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After the successful docking of Kosmos-186 and Kosmos-188, the Soviet press released multiple and consistent artistic impressions which were clearly a disinformation effort about the true design of the Soyuz 7K-OK spacecraft. The images created confusion about the historic mission for decades to come. Click to enlarge.
Soviet stamps issued in 1968 celebrating the first automated docking of Kosmos-186 and Kosmos-188 spacecraft. Notable are highly stylized and clearly coordinated depictions of the spacecraft aimed to desinform the public about their real design or its connection to the Soyuz project. Anatoly Zak's collection.