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The Soyuz-6/7/8 mission and radio observations thereof

  • ️Sven Grahn
Sven Grahn

1969 - a pivotal year

After the flight of Soyuz-4 and -5 the Soviet manned space program was in a somewhat awkward situation. The techniques tested in the Soyuz-4/5 mission were applicable to the manned lunar landing mission (EVA transfer between two docked vehicles), but the docking systems and space suits would be different. According to an entry in General Kamanin's (10) diary for 10 February 1969 TsKBEM (8) plans for 1969 were a week-long solo flight with two cosmonauts followed by a week-long docked flight with two spacecraft and five cosmonauts. The leadership (Ustinov (6) and Kerimov (7)) was not satisfied and demanded something more solid. Of course, early 1969 was a pivotal period. Apollo had just flown around the Moon and a lunar landing was expected in the summer. The Soviet Union was planning to test its N-1 Moon rocket and also to fly its automatic lunar sample returner during the year. The 7K-L1 Zond was not ready to fly and had been made more or less meaningless by the flight of Apollo-8. But chances to fly cosmonauts to the Moon were therefore practically nil. Therefore something else had to be invented, but the choices were not so attractive. There was a distinct requirement to test the "Kontakt" docking system for the N1-L3 lunar landing project in earth orbit, but that may have seemed like a repeat of earlier feats.

Therefore the solo and docking flights outlined for 1969 by TsKBEM were combined into a joint flight of three spacecraft at a meeting of the Soyuz State Commission 25 April 1969.  The plan was to fly spacecraft 14, 15 and 16  together in August 1969 Spacecraft 15 and 16 would dock and #14 would rendezvous with the docked pair and take pictures of it as well as performing a welding experiment. A test flight with "Kontakt" docking system was planned for the end of 1969. Kamanin describes the many twists and turns of crew selection, but the main event in this process was that the crew for the active docking ship, Nikolayev and Sevastyanov, did not perform well enough in docking simulations. It was not until a meeting of the VPK (9) on 18 September that the final crew assignments and planned launch date was set. The prime crew assignments and choice of radio call signs (actually a way of giving the crews the designations A, B and C) were as shown in the table on right. The crews left for Baikonur on 22 September expecting the three launches to take place on 5, 6 and 7 October, but the flights were delayed by the fact that the Politburo had not yet approved the mission. The Politburo decision came on 30 September and on the following day the State Commission decided to load the spacecraft with fuel and set the launch dates for 11, 12 and 13 october. The launch pads to be used were Area 31, Area 1 and Area 31 respectively. [This section of this article is based on the text in (1)]

Rumors in Moscow and the launches commence

On Friday 10 October 1969 UPI reported from Moscow via Radio Sweden that a mission with three manned spacecraft was immediately imminent. And, indeed, the following day at 1110.00 UT Soyuz-6 was launched and announced by Soviet media an hour later (5). When Soyuz-7 was launched the following day at 1044.42 UT the rumors from Moscow said that the third spacecraft would be manned by veteran cosmonauts. The launch was announced by Soviet media 45 minutes after lift-off (5). While waiting for the launch of Soyuz-8 the Soyuz-7 crew used an optical device Svinets (Russian for the metal lead) to try to detect the hot flames of missiles launched from Soviet territory. Finally, Soyuz-8 left Baikonur at 1019.09 UT on 13 October and Soviet media announced the launch at 1055 UT (5). Three spacecraft and seven humans were in space simultaneously!

Rendezvous operations and docking attempts

Available orbital data
During 14 and 15 October several attempts to dock Soyuz-8 to Soyuz-7 were made, but it is hard to follow these attempts in the rather meager collection of orbital data available from US sources. The figure below shows the rather scattered data points available. In this graph the initial data or Soyuz-7 have been discarded because they seem to be in error. In the figure below I have tried to depict the relative position of the spacecraft at the launch of Soyuz-8 and their relative motion during the following 24 hours. Because of the lack of good orbital data, I only claim that this picture shows the overall situation at the launch of Soyuz-8. Soyuz-8 was ahead of Soyuz-7 and Soyuz-6 was behind. However, the figure shows Soyuz-6 falling even further behind, but I think this is not correct. Probably Soyuz-6 lowered its orbit slightly to pull ahead and approach Soyuz-7.

Visual observation at Kettering, England late on 13 October
In the evening of 13 October the three craft were observed by Mr. Geoff Perry  at Kettering, England as they passed over the Midlands. Soyuz-8 was seen passing a particular constellation in the sky about 45 degrees above the horizon in SSE at 1756:21.4 UT, Soyuz-7 at 1803:13.0 UT and Soyuz-6 at 1804:41.0 UT, all at magnitude +0.5 (3). At the same time strong signals on shortwaves from the spacecraft were picked up at Kettering. This visual observation means that the range between Soyuz-8 and Soyuz-7 was about 3200 km, while the range between Soyuz-7 and Soyuz-6 was only 686 km behind.

Rendezvous attempt on 14 October
The original plan was to let Soyuz-8 dock with Soyuz-7 about 24 hours after the launch of Soyuz-8, just like when Soyuz-4 docked with Soyuz-5 in January 1969. Soyuz-7 was the passive craft and Soyuz-8 the active craft. Orbital maneuvers calculated from the ground brought Soyuz-8 to within 1  km of Soyuz-7, but the Igla automatic rendezvous system failed to provide a "lock-on" between the two craft. The two craft drifted away to 3 km distance before mission control had decided that the crew of Soyuz-8 could perform the rendezvous manually if the range was within 1500 meters. Another try was scheduled for the following day.

Visual observation in England late on 14 October
The well known satellite orbits expert Desmond KIng-Hele at RAE, Farnborough saw two objects "12 km" apart at 1743 UT while Pierre Neirinck also observing from England saw two object 3.5 degrees of arc apart at the same time (3). Neirincks observation corresponds to maybe 30 km at a range of 500 km. However, the execrate location of Neirinck's observation is unknown, so perhaps the two observations match. Neirinck also saw a third object one minute later. If this was Soyuz-6 it was 470 km away.

Rendezvous attempts on 15 October
The plan was to come within 1 km at 0600 UT on 15 October, bit it was only at 0940 UT that Soyuz-7 and Soyuz-8 were close enough (1700 m) for a manual attempt at rendezvous and docking to be made. But the task, using only the Approach and Orientation engines and not the main orbit correction engine, proved too difficult and the relative velocity was excessive. The two craft passed each other at 500 meters range. In the evening the same day Soyuz-6, which did not carry Igla, was maneuvered to a distance of 800 meters from Soyuz-7 using a control panel in the orbital module of Soyuz-6. There were further maneuvers by Soyuz-8 the following day (orbit 49 & 51) but it is unclear if these were connected to additional rendezvous attempts.

CIA's summary of events - gathered from radio intercepts?
In (11) there is an interesting summary of the docking attempts.

"... The five rendezvous attempts made during the mission were all unsuccessful for several different reasons. The first failed because the automatic rendezvous system [i.e. Igla] would not indicate radar lock-on between Soyuz 7 and 8. Two orbits later the first manual rendezvous attempt was made but it was broken off after Soyuz 8 used more than the authorized amount of attitude-control propellant. A second manual attempt, made the next day, failed because Soyuz 8 did not properly control its lateral velocity relative to Soyuz 7. The attempt by Soyuz 6 to carry out a cosmonaut-controlled rendezvous with the two other spacecraft failed because of insufficient time to correct for a three kilometer out-of-plane separation between it and the other vehicles. The final manual attempt at rendezvous and docking between Soyuz 7 and 8 was poorly timed and the vehicles could not establish the correct interval and relative velocity between them required for docking operation before they entered the earth's shadow... "
I cannot escape the impression that most of this information was gateherd from air-to-ground voice intercepted by monitoring stations in Europe and elsewhere!

The mission ends

  • Soyuz-6 landed on 16 october at 0952.47 UT 180 km NW of Karaganda. At 0330 UT a welding attempt had been made in the depressurized orbital module. When cosmonauts went back to the module to fetch samples they saw that the welding device had almost burned a hole in the module wall. After retreating for a while to the descent module, Kubasov later retrieved the samples.
  • Soyuz-7 landed at 0925.05 UT on 17 october 155 km NW of Karaganda.
  • Soyuz-8 came down at 0909.58 UT 145 km north of Karaganda.

Telemetry on shortwaves

Even though TASS did not announce any transmission frequencies for this mission much telemetry on shortwaves (15.008 MHz and 20.008 MHz) was received by the Kettering Group (4). Actually signaling on 15.008 MHz dominated as can be seen from the figure below. No signals at all were received between 0300 UT and 1000 UT. Most signaling occurred when the craft were outside the direct visibility from the Soviet Union, which confirms the main purpose of this slow speed telemetry link - to provide rudimentary status information during the non-visibility period. Of course tracking ship provided some coverage, but only intermittent.. An exception to this general pattern was 15 October 1969, when short-wave signaling was intense during passes over the USSR.

Here is what I wrote in a letter (2) to Geoff Perry:

... In a way signals on October 13 established a pattern that was to be adhered to during almost the rest of the flight. The pattern is: Signals on 20 MHz on the first orbit of the day which passes Yevpatoria (Crimea tracking site) and then again on the southbound transit over the Crimea 4.5 hours later. During this transit the frequency change to 15 MHz is commanded...

... The reason for the frequency change is quite obvious. After about 1700 UT the 20 MHz frequency is practically "dead", but 15 MHz keeps "alive" well past midnight. ...

... the time between first and last signals on 15 October was 12 hours and 44 minutes which certainly is a record for me and shows what the Russians have intended the HF telemetry system for. While the spacecraft are out of sight from Soviet tracking stations and ships while the cosmonauts are sleeping the HF telemetry link provides data on the functioning of vital systems on board. The radio link with the Soviet Union is never lost, and in case of emergency the HF frequencies can also be used for voice transmission. ...

... During the evening hours of 14 October there were very long duration transmissions as on the 13 th. The pattern for these transits are typical of ionospheric wave guide propagation; a rather constant signal level after an initial high level. ...

... On two of the evening [16 October] orbits the so-called "antipode effect" could be noticed, i.e. when the spacecraft passes the signal strength goes up a bit ...

It was during the Soyuz6/7/8 mission that the matter of biomedical subcommutation was first discovered. This matter is described in detail in the article about Soyuz-4/5. After the biomedical subcommutation had been discovered in October 1969, it was possible to show, by going back to old recordings, that the same effect was present during the previous mission in January 1969 and, had we only known about it, this characteristic of the telemetry could have been used to follow the transfer of two crew members from Soyuz-5 to Soyuz-4.

However, it was in signals recorded at about 1800 UT on 13 October 1969 that Geoff Perry at Kettering Grammar School discovered a strong variation in the length of telemetry word 8. He discovered that in the morning of 14 October 1969 while playing back the signals recorded the previous evening. Here is what he wrote in his diary (3):

"... 14 October 1969 Put Derek's signals from previous night's transit of Soyuz-8 on pen [recorder]. Observed variation in length of fourth and eighth words of frame. Assumed that it might be due to spacecraft tumbling in drifting mode whilst cosmonauts asleep. ..."
As described in the Soyuz-4/5 article, analysis done in a physics class on 15 October showed that the change in word-8 was regular, a kind of subcommutation. Signals received at Kettering at 1402-1420 UT on that day confirmed the analysis. When comparing with signals from Soyuz-4/5 it was obvious that word 8 in the telemetry frame signaled which cosmonaut was "on-line" for other measurements, probably in word 4. Geoff Perry presented these results the following day in a talk at a meeting in London of the Institution of Electronic and Radio Engineers! (3)

Other observations

Voice uplink on shortwaves
During this mission, just as during previous Soyuz flights, Chris van den Berg in the Netherlands picked up very clear voice uplink on shortwaves to the crew. This was probably intended as  a back-up to the VHF link. The messages sent this way was times for upcoming VHF passes over Soviet ground stations, but also other data and greetings (listen here to a greeting from the Baltic Fleet aviation to cosmonaut Shonin) . the transmitters used were very strong short-wave broadcast stations that had a great potential for reaching the spacecraft irrespective of their location. When not transmitting instructions the channels was held clear by music programming and other material. You can read an account of this fascinating story here.

Voices during recovery
I listened intensively on shortwaves during the morning when Soyuz-8 landed. Everyone was expecting a landing since the two other craft were already down. I picked up some scattered voice signals on 20.008 MHz at 0540 UT, but otherwise there was silence. At 0905 UT intense voice activity started on 20.008 MHz with statements like "konets polyot, konets polyot" [end of flight!]. This voice activity continued until 0923. The spacecraft touched down at 0909.58 UT and Radio Moscow announced the successful landing at 0930 UT.

References and Notes

  1. Bart Hendrickx, The Kamanin Diaries 1969-171, JBIS, Vol 55 No. 9/10, pp.312-360.
  2. Letter from Sven Grahn to Geoff Perry, 18 October 1969.
  3. Perry, G.E, Day-to-day-log for October 1969. Personal communication to Sven Grahn, 1969
  4. "The joint flight of Soyuz 6, Soyuz 7 and Soyuz 8, 1969-85A, 1969-86A and 1969-87A."  Internal Kettering Group memo written by Geoff Perry and dated 24 February 1970.  (See picture above of this and other similar tracking summaries)
  5. Swedish daily Svenska Dagbladet, "Fine coverage by Soviet TV", 14 October 1969
  6. Ustinov, Dimitri  was the secretary of the Central Committee for defense and space 1965-76.
  7. Kerimov, Kerim Aliyevich, the chairman of the State Commission for Soyuz 1966-91.
  8. TsKBEM was the then valid name for Korolev's organization formerly known as OKB-1, now known as RKK Energia
  9. VPK, The Military-Industrial Commission of the Presium of the USSR Council of Ministers. At this time its chairman was LV Smirnov.
  10. Nikolai Kamanin was a lieutenant general in the Soviet Air Force and  a well-known aviator. In 1960 he was appointed to a position where he supervised the selection, training, and administration of new cosmonauts.
  11. Siddiqi, Asif A,, "Challenge to Apollo", NASA SP-2000-4408, p.708, citing: US Centrail Intelligence Agency, "National Intelligence Estimate 11-1-71: The Soviet Space Program." Washington DC, July 1, 1971. p.29


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