Soyuz 7K-S and 7K-ST

[jcm]

I've been reconstructing the early Soyuz T missions, starting with Kosmos-670.
Beginning with Kosmos-1001 (the first 7K-ST)  the orbital module was separated prior to deorbit. For the three 7K-S missions (Kosmos-670, 772 and 869) no orbital module was tracked so presumably the BO was separated
during reentry (after deorbit)
Why the difference in profile? The change to a 3-person crew gave too large
a downmass to deorbit the BO as well?

For Kosmos-1001 the BO was cataloged on Apr 14, a day before deorbit.
Same story for Kosmos-1074, the first BO elsets are almost 24 hr prior to reentry.  Did this represent a test of the ability of the vehicle to remain
in orbit without the BO, or were there aborted deorbit attempts on these missions? Just curious if anyone knows...

Some of the Soyuz T orbital modules were miscataloged as Salyut debris.
For the record, I believe these are the Soyuz T orbital modules prior to Soyuz TM-6 where post-retrofire jettisons resumed:
Kosmos-1001  1978-36C? 10804
Kosmos-1074  1979-008C? 11315
Soyuz T           1977-97BR 11740
Soyuz T-2        1977-97BS  11832
Soyuz T-3        1977-97CN   12090
Soyuz T-4        1977-97DJ   12489
Soyuz T-5         1982-33V   13436
Soyuz T-6        1982-33L     13332
Soyuz T-7        1982-33AF   13700
Soyuz T-8  1983-35C  14029
Soyuz T-9  1983-62C  14519
Soyuz T-10 1984-14E 14918
Soyuz T-11 1984-32C 15345
Soyuz T-12 1984-73C 15136
Soyuz T-13 1985-43C 16097
Soyuz T-14 1985-81C 16261
Soyuz T-15 1986-22C 16863
Soyuz TM   1986-35C 16748
Soyuz TM-2 1987-13C 18242
Soyuz TM-3 1987-63C 18723
Soyuz TM-4 1987-104C 19225
Soyuz TM-5 1988-48C 19464

The only other Soyuz orbital modules cataloged in orbit were Soyuz-12 and
Kosmos-613, I believe - at least, they left long-lived debris objects in orbit and I don't know what else they could be.


As usual, corrections appreciated...

 Jonathan

[Danderman]

The only other Soyuz orbital modules cataloged in orbit were Soyuz-12 and
Kosmos-613, I believe - at least, they left long-lived debris objects in orbit and I don't know what else they could be.

I believe that Soyuz 12 carried some sort of camera on its nose in lieu of a docking adapter, and perhaps the camera was jettisoned prior to retrofire.

[Danderman]

Along a similar vein were the "torus tanks" that were jettisoned during the earliest Soyuz missions. It was never really clear what those were, although some suggested that this was a docking computer.

[GClark]

The only other Soyuz orbital modules cataloged in orbit were Soyuz-12 and
Kosmos-613, I believe - at least, they left long-lived debris objects in orbit and I don't know what else they could be.

I believe that Soyuz 12 carried some sort of camera on its nose in lieu of a docking adapter, and perhaps the camera was jettisoned prior to retrofire.

I thought that one was Soyuz 13.

[B. Hendrickx]

I've been reconstructing the early Soyuz T missions, starting with Kosmos-670.
Beginning with Kosmos-1001 (the first 7K-ST)  the orbital module was separated prior to deorbit. For the three 7K-S missions (Kosmos-670, 772 and 869) no orbital module was tracked so presumably the BO was separated
during reentry (after deorbit)
Why the difference in profile? The change to a 3-person crew gave too large
a downmass to deorbit the BO as well?

The Russians explained the jettisoning of the Soyuz-T orbital module prior to the de-orbit burn as a propellant saving measure. Here's one Soviet-era source for that :
http://epizodsspace.airbase.ru/bibl/znan/1980/12/12-sovr-dost.html

The difference between 7K-S and 7K-ST was not only the switch from a 2-man to a 3-man crew. Whereas 7K-S was a vehicle for solo Earth-orbital military missions, 7K-ST was destined to become a space station ferry. Presumably, they wanted to have more propellant margins for docking maneuvers.

Of course, the practice of shedding the orbital module before retrofire was abandoned after the Soyuz TM-5 de-orbit problems in September 1988, when the Soviet-Afghan crew was forced to spend 24 hours in the cramped confines of the descent module.

I wonder about Soyuz-12 and Kosmos-613. If the two-man Soyuz (7K-T) had the capability of jettisoning the orbital module before the de-orbit burn, why was that demonstrated on just two missions?

   

[jcm]

The only other Soyuz orbital modules cataloged in orbit were Soyuz-12 and
Kosmos-613, I believe - at least, they left long-lived debris objects in orbit and I don't know what else they could be.

 

I believe that Soyuz 12 carried some sort of camera on its nose in lieu of a docking adapter, and perhaps the camera was jettisoned prior to retrofire.

I thought that one was Soyuz 13.

The Soyuz-13 Orion-2 telescope cover is 06984  1973-103C
The Soyuz-22 MKF-6 telescope cover is 09425  1976-093C 
The Soyuz-16 APAS simulator is probably 07565  1974-096E 

If anyone has the jettison times for these objects, please share them!

[jcm]

Further investigation shows pre-retrofire ejected objects (possibly orbital modules)
for other early 7K-T flights - Kosmos-573  (object C, 6702),  Soyuz-17 (1974-104N, 7662)
and Soyuz-18  (8055, 1974-104U). If these are not orbital modules, it would be interesting to know what they were.

Also, object 7997 1974-104S ejected about 1975 Jun 28 from Salyut-4 was very long lived, much denser than the usual garbage bags. It reentered in March 1976. 1975-01J ejected 1975 Feb 5? and 1975-44C ejected 1975 Jun 5-ish also were long-lived.
I bet they were *something* interesting...

[Edit:  Kosmos-496, the post Soyuz 11 test flight, also has an object
cataloged about the time of recovery]

[B. Hendrickx]

What is interesting is that all the 7K-T vehicles that displayed this behaviour (Kosmos-573, Soyuz-12, Kosmos-613, Soyuz-17, Soyuz-18) were from the production batches for the second, third and civilian Salyuts (DOS-2 (which was lost in a launch failure in 1972), DOS-3 (which failed shortly after orbit insertion and was called Kosmos-557) and DOS-4 (orbited as Salyut-4)). 

Soyuz-13 was specifically built for its solo mission (not reoriented from DOS) and all other Soyuz vehicles flown at the time were 7K-S(T) (Soyuz-T), the Almaz version of Soyuz or the ASTP-related Soyuz vehicles (7K-TM).

[jcm]

What is interesting is that all the 7K-T vehicles that displayed this behaviour (Kosmos-573, Soyuz-12, Kosmos-613, Soyuz-17, Soyuz-18) were from the production batches for the second, third and civilian Salyuts (DOS-2 (which was lost in a launch failure in 1972), DOS-3 (which failed shortly after orbit insertion and was called Kosmos-557) and DOS-4 (orbited as Salyut-4)). 

Soyuz-13 was specifically built for its solo mission (not reoriented from DOS) and all other Soyuz vehicles flown at the time were 7K-S(T) (Soyuz-T), the Almaz version of Soyuz or the ASTP-related Soyuz vehicles (7K-TM).

Exactly, yes. In particular, Soyuz-20, even though it went to Salyut 4, was an A9 model (Almaz variant), and there doesn't seem to be an object associated with it.  So whatever the objects are (and the BO seems likely to me) they are associated with the DOS-2 to DOS-4 7K-T, while the Salyut-6 Soyuzi adopted the Almaz-version behaviour.
 
We know of course that the BO was a post-retrofire jettison for Soyuz-11
(and indeed there are no anomalous objects tracked for the Salyut-1 missions). The other thing that changed between Soyuz-18  and Soyuz-25
was the switch from the 11A511 to 11A511U launch vehicles. Maybe the pre-retrofire jettison was associated with weight increases due to post Soyuz-11-tragedy mods and was no longer needed once the Soyuz-U rocket came along  (with the Almaz Soyuzi being different enough to be treated separately)

[Bob Shaw]

On a similar, but related subject - I have a vague memory of an orbital module remaining attached to Mir on one occasion. I don't know whether it would be airtight, obviously it'd need to have an uncoupling system unlike that used between the Apollo CSM and LM which I always understand left the LM airless.

Was an OM attached to Mir, was this ever considered and any notions about it's potential as a source of mini-modules for trash stowage etc?

[Danderman]

On a similar, but related subject - I have a vague memory of an orbital module remaining attached to Mir on one occasion. I don't know whether it would be airtight, obviously it'd need to have an uncoupling system unlike that used between the Apollo CSM and LM which I always understand left the LM airless.

Was an OM attached to Mir, was this ever considered and any notions about it's potential as a source of mini-modules for trash stowage etc?

Never happened.

Western observers saw the jettisoned OMs as leading to a space station with attached OMs.  On a technical basis, this is a non-starter, since OM systems connect to the PAO/DM for all functions.

[jcm]

On a similar, but related subject - I have a vague memory of an orbital module remaining attached to Mir on one occasion. I don't know whether it would be airtight, obviously it'd need to have an uncoupling system unlike that used between the Apollo CSM and LM which I always understand left the LM airless.

Was an OM attached to Mir, was this ever considered and any notions about it's potential as a source of mini-modules for trash stowage etc?

Never happened.

Western observers saw the jettisoned OMs as leading to a space station with attached OMs.  On a technical basis, this is a non-starter, since OM systems connect to the PAO/DM for all functions.

You may be thinking of the Docking Module brought up by STS-74; I have the impression that its design heritage (tooling diameter etc) comes from the OM.

[Danderman]

On a similar, but related subject - I have a vague memory of an orbital module remaining attached to Mir on one occasion. I don't know whether it would be airtight, obviously it'd need to have an uncoupling system unlike that used between the Apollo CSM and LM which I always understand left the LM airless.

Was an OM attached to Mir, was this ever considered and any notions about it's potential as a source of mini-modules for trash stowage etc?

Never happened.

Western observers saw the jettisoned OMs as leading to a space station with attached OMs.  On a technical basis, this is a non-starter, since OM systems connect to the PAO/DM for all functions.

You may be thinking of the Docking Module brought up by STS-74; I have the impression that its design heritage (tooling diameter etc) comes from the OM.

Yep, the Shuttle Mir Docking Module and Rassvet are derivatives of the OM.  Basically, the two ISS Russian airlocks are, as well.

[B. Hendrickx]

Exactly, yes. In particular, Soyuz-20, even though it went to Salyut 4, was an A9 model (Almaz variant), and there doesn't seem to be an object associated with it.  So whatever the objects are (and the BO seems likely to me) they are associated with the DOS-2 to DOS-4 7K-T, while the Salyut-6 Soyuzi adopted the Almaz-version behaviour.
 
We know of course that the BO was a post-retrofire jettison for Soyuz-11
(and indeed there are no anomalous objects tracked for the Salyut-1 missions). The other thing that changed between Soyuz-18  and Soyuz-25was the switch from the 11A511 to 11A511U launch vehicles. Maybe the pre-retrofire jettison was associated with weight increases due to post Soyuz-11-tragedy mods and was no longer needed once the Soyuz-U rocket came along  (with the Almaz Soyuzi being different enough to be treated separately)

The reason that the Soyuz vehicles built for DOS-2/3/4 may have ejected the BO prior to retrofire and the Almaz versions did not could be that the DOS stations were in higher orbits than Almaz, meaning the DOS-targeted vehicles needed more propellant to reach the station. Ejecting the BO prior to retrofire gave them extra propellant margins.

[Danderman]

The only other Soyuz orbital modules cataloged in orbit were Soyuz-12 and Kosmos-613, I believe - at least, they left long-lived debris objects in orbit and I don't know what else they could be.

I believe that Soyuz 12 carried some sort of camera on its nose in lieu of a docking adapter, and perhaps the camera was jettisoned prior to retrofire.

I thought that one was Soyuz 13.

http://www.spacefacts.de/mission/english/soyuz-12.htm

"A multispectral camera in the orbital module was used in coordination with aircraft to photograph Earth. The intention was to survey crop and forest conditions, it was reported."

Also:

"The material acquired by the aircraft laboratory, in conjunction with data from terrestrial observation and multi spectral photographs supplied by the crew of the Soyuz 12 spaceship, are being processed in the Institute for Space Research, Moscow State University and many other academic and departmental scientific and research institutions."

from: "Ispol'zovaniye Kosmicheskikh Sredstv dlya Izucheniya Zemnykh Resursov i Kontrolya Okruzhayushchey Sredy. Samoletnyy Eksperiment," Meteorologiya i Gidrologiya, No. 4, April 1974, pp. 25-29.

I suspect that the object left in orbit by Soyuz 12 was the cover for the LKSA camera.

[Danderman]

Exactly, yes. In particular, Soyuz-20, even though it went to Salyut 4, was an A9 model (Almaz variant), and there doesn't seem to be an object associated with it. 

If the unmanned Soyuz-20 was an Almaz related Soyuz and not a test of Soyuz-T or Progress, what was its function?

Although the crewed Almaz Soyuzes jettisoned their orbital modules prior to retrofire, this particular Soyuz did not require the jettison, since without a crew or cargo, this would have been a very light spacecraft.

This mission also demonstrates that the jettison before/after retrofireconfiguration for Almaz A9 was programmatically driven and not technically driven, in the sense that an A9  did not necessarily have to jettison its OM prior to retrofire. A9 had this as an option, not a requirement.

[jcm]

Exactly, yes. In particular, Soyuz-20, even though it went to Salyut 4, was an A9 model (Almaz variant), and there doesn't seem to be an object associated with it. 

If the unmanned Soyuz-20 was an Almaz related Soyuz and not a test of Soyuz-T or Progress, what was its function?

Although the crewed Almaz Soyuzes jettisoned their orbital modules prior to retrofire, this particular Soyuz did not require the jettison, since without a crew or cargo, this would have been a very light spacecraft.

This mission also demonstrates that the jettison before/after retrofireconfiguration for Almaz A9 was programmatically driven and not technically driven, in the sense that an A9  did not necessarily have to jettison its OM prior to retrofire. A9 had this as an option, not a requirement.

On the contrary, the crewed Almaz Soyuzi (A9) had a *post* retrofire jettison. It was the early A8 models that had pre-retro jettison, as per my postings above. So Soyuz-20 is consistent.
I imagine that it was a Progress-related test to verify the automatic docking system, flown on a spare Soyuz (which happened to be an A9) since Progress wasn't ready.

[jcm]

The only other Soyuz orbital modules cataloged in orbit were Soyuz-12 and Kosmos-613, I believe - at least, they left long-lived debris objects in orbit and I don't know what else they could be.

I believe that Soyuz 12 carried some sort of camera on its nose in lieu of a docking adapter, and perhaps the camera was jettisoned prior to retrofire.

I thought that one was Soyuz 13.

http://www.spacefacts.de/mission/english/soyuz-12.htm

"A multispectral camera in the orbital module was used in coordination with aircraft to photograph Earth. The intention was to survey crop and forest conditions, it was reported."

Also:

"The material acquired by the aircraft laboratory, in conjunction with data from terrestrial observation and multi spectral photographs supplied by the crew of the Soyuz 12 spaceship, are being processed in the Institute for Space Research, Moscow State University and many other academic and departmental scientific and research institutions."

from: "Ispol'zovaniye Kosmicheskikh Sredstv dlya Izucheniya Zemnykh Resursov i Kontrolya Okruzhayushchey Sredy. Samoletnyy Eksperiment," Meteorologiya i Gidrologiya, No. 4, April 1974, pp. 25-29.

I suspect that the object left in orbit by Soyuz 12 was the cover for the LKSA camera.

But (unlike the Soyuz-13 object) the Soyuz-12 object was not cataloged until Sep 29, the reentry date - a camera cover would have come off on launch day.

Not proof, since NORAD maybe just missed it at first.

I had the impression that LKSA was just a handheld thing like a Hasselblad, not a full up exterior installation like the Soyuz-22 MKF-6M.

[Danderman]

Exactly, yes. In particular, Soyuz-20, even though it went to Salyut 4, was an A9 model (Almaz variant), and there doesn't seem to be an object associated with it. 

If the unmanned Soyuz-20 was an Almaz related Soyuz and not a test of Soyuz-T or Progress, what was its function?

Although the crewed Almaz Soyuzes jettisoned their orbital modules prior to retrofire, this particular Soyuz did not require the jettison, since without a crew or cargo, this would have been a very light spacecraft.

This mission also demonstrates that the jettison before/after retrofireconfiguration for Almaz A9 was programmatically driven and not technically driven, in the sense that an A9  did not necessarily have to jettison its OM prior to retrofire. A9 had this as an option, not a requirement.

On the contrary, the crewed Almaz Soyuzi (A9) had a *post* retrofire jettison. It was the early A8 models that had pre-retro jettison, as per my postings above. So Soyuz-20 is consistent.
I imagine that it was a Progress-related test to verify the automatic docking system, flown on a spare Soyuz (which happened to be an A9) since Progress wasn't ready.

You are correct, I had it backwards.
A9 = Almaz
A8 = DOS

correct?

[B. Hendrickx]

On the contrary, the crewed Almaz Soyuzi (A9) had a *post* retrofire jettison. It was the early A8 models that had pre-retro jettison, as per my postings above. So Soyuz-20 is consistent.
I imagine that it was a Progress-related test to verify the automatic docking system, flown on a spare Soyuz (which happened to be an A9) since Progress wasn't ready.

Soyuz-20 (serial number 11F615A9 nr. 64) was originally supposed to become the first of three vehicles to fly to OPS-3/Salyut-5. However, it was sent on an unmanned mission to DOS-4/Salyut-4 instead to test modifications that made it possible for both the DOS and Almaz versions of 7K-T to remain docked to the station for 90 rather than 60 days. To compensate for the transfer of an "Almaz" Soyuz to the DOS programme, the first vehicle slated to fly to DOS-5/Salyut-6 (11F615A8 nr. 41) was transferred to the Almaz programme and launched to Salyut-5 as Soyuz-21.