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)]
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!
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...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.... 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 ...
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)
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.