Soyuz-4
and Soyuz-5 finally carried out the original mission foreseen for the
first
Soyuz mission in 1967, i.e. docking between two manned spacecraft and
transfer
of crew members between the craft. In early 1969 this mission was
almost
obsolete and had little connection with the major Soviet manned
spaceflight
project at the time, the N1-L3 manned lunar mission.
However, the Soyuz-4/5 mission was a technical milestone important for the future development of manned space stations. The date of this mission was not known ahead of time and there were no pre-launch rumors in Moscow during the days leading up to the launch. But after the flight of Soyuz 3 the "chief designer" (now known to be V.P Mishin) told reporters that the next mission would involve the docking of two Soyuz craft and that "we are already prepared for a new launch" (2).
The launch of the first craft was initially planned for January 13, but a problem in the launch vehicle delayed the lift-off by one day (6).
Launch
of Soyuz-4 on 14 January 1969At injection into orbit the two craft were about 1200 km away from each other and according to Soviet sources two-way contact was established between the two craft (1). The orbit of Soyuz-5 was adjusted at 1430 UT to reach 211-253 km. Soyuz-5 was the passive ship and Soyuz-4 was the active chaser craft.
The figure below shows the range-rate between the two craft (negative range-rate means that the two craft are approaching). Near closest approach the range-rate fell to values well within the capability of Igla to handle.
The craft approached to within 40 meters as they crossed the African coast at 0805 UT. The docking occurred at 0820 UT while passing over Soviet territory within view of Yevpatoria in the Crimea (see map below). When the two docked craft passed over South America on the next orbit at about 0925 UT Yevgeny Khrunov peformed an EVA to transfer from Soyuz-5 to Soyuz-4. Alexei Yeliseyev repeated this maneuver when the docked vehicles passed over the Soviet Union about half an hour later. During this period signals on 20.008 MHz were received at Kettering (see figure below).
Undocking occurred again over the radio horizon of Yevpatoria at 1255 UT.
As for myself, I had just started to work full time for the Institute of Meteorology at the University of Stockholm after having finished my M.Eng degree. Therefore, I had to rely on my time switch to record signals while at work. This also limited me to covering just one frequency, because I had to leave the radio (an Eddystone EC-10) switched on and tuned to a precise frequency when I left home. On 14 january I learned of the launch when I picked up the afternoon papers at 1630 UT and saw a little flash item about the launch of Soyuz-4. The next day, when Soyuz-5 was launched I returned home for an hour around lunch to listen to the recorded tape (which was empty) and pick up signals on 20.008 MHz in real time. This became my routine for the two following days - using the time switch and going home for lunch to pick up signals in real time.
Not until the flight of Soyuz-6,-7-,8 was the significance of this was understood. Soyuz-8, with a two-man crew exhibited only two word lengths, medium and long. Then it was fully understood that the number of levels that word 8 could assume represented the number of crew members on board. At the time of the recording below where word 8 assumes three different lengths, there were indeed three crew members on board Soyuz-4. It seems that word 8 indicates which cosmonaut is being sampled by other telemetry channels. Indeed, word 4 was found to show variations consistent with such a scheme (8). Indeed, in the figure below it is easy to see variations of word 4 between frames.
Here is Geoff Perry's
account
of how he discovered the "biomedical subcommutation" in the signal from
Soyuz-8 (9):
"... 15 October 1969: ... Periodic variation of eighth word found to be 2.0 min; the same as on previous day, so decided that this was not due to tumbling after all. John Marshall [another teacher at Kettering Grammar School] had suggested whilst we still thought it to be tumbling that the length would provide an attitude read-out. Devoted the two-period lesson in afternoon with 4P to evolving theory that this was evidence of sub-commutation - the alternate sampling of two cosmonauts at one minute intervals. This suggested that at a certain time the sequence of three medium length and four long pulses should change to four medium followed by three long. This prediction was confirmed during the transit from 1402 to 1420 Z and again on the following transit. Felt great excitement at this discovery. .....16 October 1969.... I mentally determined to go back to the Soyuz 4 and 5 tape recordings to see if I could locate evidence for a three-cosmonaut crew. ....
.. 27 October 1969 .. Spent morning (and part of yesterday afternoon) making pen records from Soyuz 4 and 5 tapes. It is possible to see three cosmonauts in Soyuz 5 as the eighth word shows the following sequence of short, medium an long pulses: SSS MMM LLL SSS MMMM LLL SSSS etc. Moreover you can see this pattern appear in Soyuz 4 after they have performed the EVA crew transfer ..."
The entire telemetry sequence is available here (warning! the file size is 0.6 MB) for listening. The reader can try identifying the subcommutation by simply listening to the recording.
Voice
on shortwavesHowever, a short voice transmission was picked up from Soyuz-5 in 17 January 1969 at 1231 UT on 20.008 MHz when Boris Volynov could be heard calling "Zarya ya Baikal". Additional voice was picked up at Kettering briefly at 1505.50 UT and also at 1532-1537 UT. I had my receiver and tape recorder running under time switch control at the time, but the BFO (beat-frequency oscillator) was on preventing clear reception of the voice. Interestingly, the voice receptions coincided with passes over the horizon at Kettering.
Little did we know that
short
waves was used to broadcast messages to the crew giving times for VHF
communications
sessions. This subject is covered in a
separate article.
The end of the Soyuz-5 flight was not so routine. The original plan was to land at about 0630 UT and for Volynov to orient the ship manually for retro-fire. He even rehearsed this on the pre-landing orbit and reported that he had completed the task in the 9 minutes available. Despite this Volynov was directed to try the manual orientation. The spacecraft left eclipse at 0539 UT and the planned retro-fire was at 0548.49 UT. At about 0556 UT Volynov reported (to the ship off Africa?) that he had not had enough time to complete the maneuver. However, stored commands to carry out an automatic orientation on the next orbit had already been uplinked. The automatic sequence for orientation and retro-fire worked as planned. (12).
After the end of retro-fire the instrument module did not separate despite the fact the explosive bolts fired. Boris Volynov could see the antennas on the solar panels and realized that the instrument module was till attached. he reported this through some coded radio channel to mission control (7). This could have been on short waves soon after the end of retro-fire because the spacecraft was still out of VHF range from the Soviet Union at that time. The report could have been sent later, through VHF, when approaching Soviet ground stations, but while still not in the reentry blackout phase. It is interesting to note that signals on short waves ceased abruptly at 0732.41 UT. Myself and Christopher Wood at Fiji heard the command-off. This is normally assumed to be the time of separation of the instrument module, and in all probability it was the time when the separation pyros fired. Probably the electrical connections but not the mechanical connection between the re-entry vehicle and the instrument module were severed.
This was a life-threatening situation. Eventually, propellant tanks in the instrument module exploded due to the re-entry heat and the two modules separated. The re-entry vehicle which had taken the reentry aerodynamic and heat loads in the area of its top hatch swung around to the normal re-entry attitude and made a purely ballistic reentry. Upon landing the parachute had problems to deploy properly, but the craft landed, and the landing shock was such that Volynov was thrown across the cabin and broke some of his front teeth. A detailed account of this near-disaster can be found at James Oberg's web site. According Encyclopedia Astronautica a failure of the soft-landing rockets caused the landing to be much harder than usual (10).
The map below shows the final orbits of Soyuz-5, receptions by myself in Stockholm and Chris Wood at Fiji in addition to the planned and actual landing spot. Interestingly, TASS announced the intended landing spot and not the actual one, which was 600 km short of the planned one (7). The drama of the landing was not known at the time, it was revealed much later, in the 1990's.
