Soyuz 7K-OK No. 6 (Kosmos-186) lifts off

The Soyuz 7K-OK No. 6 (Amur) (active vehicle) lifted off on Oct. 27, 1967, at 12:30 Moscow Time from Site 31 with a deviation of just 0.02 seconds from the scheduled time. (466) In the official press reports, the spacecraft was identified as Kosmos-186.

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Final preparations

On October 19, 1967, the mission control team conducted its first dressrehersal of the joint Soyuz mission. Along with Chertok, the leading eight managers and engineers of the team included Agadzhanov, Tregub, Raushenbakh, Bolshoi, Rodin, Starinets and Gagarin.

In the meantime, the preparation of Vehicles No. 5 and No. 6 in Tyuratam hit a number of problems and delays, including burned cables in the power supply system. During the propellant loading into the SKD propulsion system of Vehicle No. 6, a membrane on the fuel valve was accidentally blown off by an errant command to the pyrotechnic system.

On October 24, the State Commission and other top officials from the TsKBEM design bureau left Moscow for Tyuratam. Before their departure, Mishin called from Moscow to Chertok in Crimea and advised the flight control team to be ready for launch no later than October 27. (466)

Chase vehicle No. 6 (Kosmos-186) lifts off first

On the morning of October 27, Chertok was asked to report to the State Commission whether the GOGU team and the entire ground-control network was ready for launch. At 08:00 Moscow Time, the four-hour readiness for launch was declared.

The Soyuz 7K-OK No. 6 (Amur) (active vehicle) lifted off on Oct. 27, 1967, at 12:30 Moscow Time from Site 31 with a deviation of just 0.02 seconds from the scheduled time. (466) In the official press reports, the spacecraft was identified as Kosmos-186, with no hint about the true nature of its mission. However, for some reason, the official communiqué contained the time of the launch, which normally would not have been included in the standard announcements associated with the Kosmos series. The orbital parameters also betrayed a spacecraft related to the previous Soyuz missions. (50) The ship was in a 209 by 235-kilometer orbit with an inclination 51.7 degrees toward the Equator. (2)

During the second revolution of the flight, mission control was able to confirm that the solar panels and all the antennas had deployed as planned. Boris Raushenbakh reported that the spacecraft had stabilized its attitude and then, as planned, entered spin stabilization with the solar panels pointing toward the Sun. Flight controllers also managed to check the operation of the DRS long-range communications system, responsible for measuring the orbital parameters of the ship and carrying telephone and TV transmissions. All these systems appeared to be functioning well. The spacecraft was also receiving good flow of electricity from solar panels and the thermal control system was also functioning well.

During Orbit 4, mission control uploaded a sequence onboard the spacecraft for testing its SKD engine and the stabilization sequence using DPO thrusters. According to Chertok, everything worked as planned (466), but Mishin's notes indicate that at least one attempt to upload the sequence was unsuccessful. (774) According to Kamanin, the orbit correction did succeed during Orbit 5. (820)

In the end, the first day of the flight was considered a success, but the problems did start on the second day. The orbit correction during Orbit 17 did not take place due to problems with the sun and star tracker.

Mission control also began having problems with uploading commands to the DRS communications system. (466) Two commands did not go through during Orbit 20. (774)

The second attempt at orbit correction during Orbit 31 was also aborted due to delays with delivering the necessary parameters to remote ground stations. Finally, the ion orientation system also exhibited periodic problems. Still, by the end of the third day, mission control was able to bring the spacecraft at the correct altitude for the rendezvous, clearing the way for the launch of the second spacecraft. (466)

Next chapter: Launch of Soyuz 7K-OK No. 5 (Kosmos-188)

(To be continued)

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The article and illustrations by Anatoly Zak; Last update: October 30, 2017

Page editor: Alain Chabot

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The Soyuz 7K-OK spacecraft during pre-launch processing. Credit: RKK Energia


A Soyuz spacecraft lifts off.