Author Topic: Deorbit engines on Soviet reconnaissance satellites  (Read 8123 times)

Offline Stan Black

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #20 on: 02/01/2013 10:16 PM »
 I'm trying to get my head around this. The 8D66 was at the rear for Zenit. A backup was added; the solid propellant 11D82. But would the 8D66 have remained at the rear? The 11D82 at the front? If it was always the plan from the days of Vostok, why does Voskhod feature a different solid propellant unit?

Offline B. Hendrickx

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #21 on: 02/01/2013 11:57 PM »
One way to check his information about the Zenit-6/8 series is to see whether they left any debris in orbit prior to the deorbit burn.
They indeed did.

That would mean Zavyalov is wrong and the most likely scenario is that the 11D452 was only used for orbital corrections and discarded prior to the deorbit burn, which was performed by an aft-mounted solid-fuel engine.

In his online book Zavyalov gives a propellant mass of 250 kg for the 11D452. The 8D66, solely used for deorbit, had a propellant mass of 280 kg. 250 kg was hardly enough both for orbit corrections and deorbit.

Offline B. Hendrickx

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #22 on: 02/02/2013 12:08 AM »
 I'm trying to get my head around this. The 8D66 was at the rear for Zenit. A backup was added; the solid propellant 11D82. But would the 8D66 have remained at the rear? The 11D82 at the front? If it was always the plan from the days of Vostok, why does Voskhod feature a different solid propellant unit?

Again, the information provided by Zavyalov should be treated with caution. The most likely scenario still is that the Zenits flew with either the 8D66 or the 11D82 deorbit engine, not with both at the same time. This is also confirmed in this book on Zenit, where it is said that the solid-fuel deorbit engine eventually replaced the liquid-fuel deorbit engine :
 
С. И. Королев, Н.К. Матвеев. Космические аппараты серии Зенит

epizodsspace.no-ip.org/bibl/korolev-s/zenit.doc
 

Offline jcm

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #23 on: 02/03/2013 01:05 AM »
I'm trying to get my head around this. The 8D66 was at the rear for Zenit. A backup was added; the solid propellant 11D82. But would the 8D66 have remained at the rear? The 11D82 at the front? If it was always the plan from the days of Vostok, why does Voskhod feature a different solid propellant unit?

Again, the information provided by Zavyalov should be treated with caution. The most likely scenario still is that the Zenits flew with either the 8D66 or the 11D82 deorbit engine, not with both at the same time. This is also confirmed in this book on Zenit, where it is said that the solid-fuel deorbit engine eventually replaced the liquid-fuel deorbit engine :
 
С. И. Королев, Н.К. Матвеев. Космические аппараты серии Зенит

epizodsspace.no-ip.org/bibl/korolev-s/zenit.doc
 


One of the biggest challenges of historical research is the confident statements made by people who were there at the time and remember what happened in great detail but completely wrongly. I've come across this talking to US CORONA veterans too - for example, that  A happened so then they did B, when in fact we know very well that B happened 2 years before A. This is why you really need both contemporary documents and modern reminiscences.

With all respect to Zavyalov's status as a participant, I think he has to be wrong.


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Offline Stan Black

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #24 on: 02/03/2013 06:55 PM »
 Remember reading somewhere Voskhod had additional solid propellant soft-landing engines under the parachute lines? Did any of the Zenit derivatives feature something similar?

Offline B. Hendrickx

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #25 on: 02/03/2013 09:12 PM »
One of the biggest challenges of historical research is the confident statements made by people who were there at the time and remember what happened in great detail but completely wrongly. I've come across this talking to US CORONA veterans too - for example, that  A happened so then they did B, when in fact we know very well that B happened 2 years before A. This is why you really need both contemporary documents and modern reminiscences.

With all respect to Zavyalov's status as a participant, I think he has to be wrong.

Yes, memories are fallible... By the way, Zavyalov may not have been personally involved in the development of the Zenit deorbit engines. The Isayev bureau worked on a wide array of projects.

Offline B. Hendrickx

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #26 on: 02/03/2013 09:21 PM »
 Remember reading somewhere Voskhod had additional solid propellant soft-landing engines under the parachute lines? Did any of the Zenit derivatives feature something similar?

In a document written by Korolyov (published in "The Creative Legacy of Academician S.P. Korolyov") it is said that the Voskhod soft-landing engine was supposed to reduce touchdown speed from 8-10 m/s to 0-2 m/s.

In the Zenit book I mentioned in an earlier post the Zenit landing sequence is described in some detail and there is no mention of a soft-landing engine. The parachute system was designed to enable a touchdown speed of 10 to 12 m/s, which was said to be sufficient to ensure the re-usability of the photographic equipment and the descent capsule itself.

Offline Stan Black

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #27 on: 02/03/2013 09:55 PM »

So a new but related question - in 1973-75 the Yantar small film capsules were test flown on Gektor satellites as "FEU-170".

The Yantar history in Novosti Kosmonavtiki tells us FEU-170 was mounted on the Zenit-2M's nose in place of the Nauka capsule, and the experiment involved recovery of the SpK capsule.

What's not entirely clear to me: did this test include test of the 11D864 deorbit motor, with FEU-170 separation and deorbit one or more orbits before recovery of the main Zenit-2M satellite? Or was it just a test of the SpK heat shield and parachute system with separation of the capsule from the Zenit-2M after the Zenit-2M's deorbit burn?

Also, what is the object that remained in orbit after recovery? Some kind of cover for the FEU-170? or an attach device?

Well that recent publication says

Quote
Спуск капсулы ФЭУ-170 № 1 был осуществлен 08.10.73

САМАРСКИЕ СТУПЕНИ СЕМЕРКИ

And the rest came down on the 9th?

http://www.zarya.info/Diaries/Zenit/Zenit-2M.php

Offline jcm

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #28 on: 02/04/2013 05:05 AM »

So a new but related question - in 1973-75 the Yantar small film capsules were test flown on Gektor satellites as "FEU-170".

The Yantar history in Novosti Kosmonavtiki tells us FEU-170 was mounted on the Zenit-2M's nose in place of the Nauka capsule, and the experiment involved recovery of the SpK capsule.

What's not entirely clear to me: did this test include test of the 11D864 deorbit motor, with FEU-170 separation and deorbit one or more orbits before recovery of the main Zenit-2M satellite? Or was it just a test of the SpK heat shield and parachute system with separation of the capsule from the Zenit-2M after the Zenit-2M's deorbit burn?

Also, what is the object that remained in orbit after recovery? Some kind of cover for the FEU-170? or an attach device?

Well that recent publication says

Quote
Спуск капсулы ФЭУ-170 № 1 был осуществлен 08.10.73

САМАРСКИЕ СТУПЕНИ СЕМЕРКИ

And the rest came down on the 9th?

http://www.zarya.info/Diaries/Zenit/Zenit-2M.php

Ah, very interesting. My reconstruction indicates Kosmos-596
landed at about 0745 UTC on Oct 9; the descent of the FEU-170 would then probably have been at around 0730 UTC (deorbit) 0755 UTC (approx touchdown) on Oct 8 (or possibly one orbit later), and the inference of
coming down on different days is that the FEU-170 did indeed include the little solid deorbit motor.

I'd love to see a TsSKB drawing or photo of the FEU-170 attached to
the Zenit-2M !
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Offline Nicolas PILLET

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #29 on: 03/17/2014 05:56 PM »
Remember reading somewhere Voskhod had additional solid propellant soft-landing engines under the parachute lines? Did any of the Zenit derivatives feature something similar?

In a document written by Korolyov (published in "The Creative Legacy of Academician S.P. Korolyov") it is said that the Voskhod soft-landing engine was supposed to reduce touchdown speed from 8-10 m/s to 0-2 m/s.

In the Zenit book I mentioned in an earlier post the Zenit landing sequence is described in some detail and there is no mention of a soft-landing engine. The parachute system was designed to enable a touchdown speed of 10 to 12 m/s, which was said to be sufficient to ensure the re-usability of the photographic equipment and the descent capsule itself.

The question of soft landing engines for Sharik-type satellites is not clear to me. I think that there is soft-landing on Bion and Foton, but I'm not sure. I've took these pictures in Samara, which make me think that the answer is "Yes, there are soft landing engines under the parachute"...

Foton-8 :
http://www.kosmonavtika.com/satellites/foton/visite/08/fig4-3.jpg

Bion-10 :
http://www.kosmonavtika.com/satellites/bion/visite/10/fig5-1.jpg
Nicolas PILLET
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Offline archipeppe68

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #30 on: 03/18/2014 07:38 AM »
This contains some diagrams of the engine and cover

http://wsn.spaceflight.esa.int/docs/EuropeanUserGuide/chapter_6_foton.pdf

Most of the drawings in that document are mine, I did the illustration job for the whole ESA's Microgravity Platform Handbook back in 2005....

P.S. I spent a whole working week inside a real Foton reentry capsule (hosted inside the ERASMUS Center) taking photos and handmade drawing to realize the technical tables.

Ciao
Giuseppe
« Last Edit: 03/18/2014 10:37 AM by archipeppe68 »

Offline Nicolas PILLET

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #31 on: 04/21/2014 06:42 PM »
Remember reading somewhere Voskhod had additional solid propellant soft-landing engines under the parachute lines? Did any of the Zenit derivatives feature something similar?

In a document written by Korolyov (published in "The Creative Legacy of Academician S.P. Korolyov") it is said that the Voskhod soft-landing engine was supposed to reduce touchdown speed from 8-10 m/s to 0-2 m/s.

In the Zenit book I mentioned in an earlier post the Zenit landing sequence is described in some detail and there is no mention of a soft-landing engine. The parachute system was designed to enable a touchdown speed of 10 to 12 m/s, which was said to be sufficient to ensure the re-usability of the photographic equipment and the descent capsule itself.

In this page, it is written that Kobalt had Soyuz-like gamma-altimeter :

http://caves.ru/threads/34180-%D0%9E%D0%B1%D1%81%D1%83%D0%B6%D0%B4%D0%B5%D0%BD%D0%B8%D0%B5-%D0%BE%D0%BF%D0%B0%D1%81%D0%BD%D1%8B%D1%85-%D0%BD%D0%B0%D1%85%D0%BE%D0%B4%D0%BE%D0%BA/page68

So, it would mean that Kobalt had soft-landing engines, since the gamma-altimeter's role is to ignite them...
Nicolas PILLET
Kosmonavtika : The French site on Russian Space

Offline Stan Black

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Re: Deorbit engines on Soviet reconnaissance satellites
« Reply #32 on: 04/21/2014 08:15 PM »
Remember reading somewhere Voskhod had additional solid propellant soft-landing engines under the parachute lines? Did any of the Zenit derivatives feature something similar?

In a document written by Korolyov (published in "The Creative Legacy of Academician S.P. Korolyov") it is said that the Voskhod soft-landing engine was supposed to reduce touchdown speed from 8-10 m/s to 0-2 m/s.

In the Zenit book I mentioned in an earlier post the Zenit landing sequence is described in some detail and there is no mention of a soft-landing engine. The parachute system was designed to enable a touchdown speed of 10 to 12 m/s, which was said to be sufficient to ensure the re-usability of the photographic equipment and the descent capsule itself.

In this page, it is written that Kobalt had Soyuz-like gamma-altimeter :

http://caves.ru/threads/34180-%D0%9E%D0%B1%D1%81%D1%83%D0%B6%D0%B4%D0%B5%D0%BD%D0%B8%D0%B5-%D0%BE%D0%BF%D0%B0%D1%81%D0%BD%D1%8B%D1%85-%D0%BD%D0%B0%D1%85%D0%BE%D0%B4%D0%BE%D0%BA/page68

So, it would mean that Kobalt had soft-landing engines, since the gamma-altimeter's role is to ignite them...

http://novosti-kosmonavtiki.ru/forum/messages/forum9/topic11293/message857911/#message857911

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