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Soyuz 3 - Blok DM
by
Danderman
on 25 Sep, 2013 17:10
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I would normally post this in the Advanced Concepts section, but people there mostly don't know a lot about Russian hardware.
Let me post this more as a question than a concept, but it occurs to me that just about any variant of Soyuz using an NK-33 as the main engine would be able to support replacing the 3rd stage (the RD-0124 based stage) and the Fregat with a Blok-DM, for the purpose of orbiting Glonass satellites. For this configuration, the 4 meter payload fairing could be used to encapsule both the Blok-DM (assuming it fits) and the payload. Since the Blok-DM would be encapsulated, there would be no need for it to fly with the normal upper body fairing, which would save about a ton of mass.
Of course, drop zones for this launcher would be different from the standard Soyuz, so I am ignoring that issue for now.
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#1
by
fregate
on 26 Sep, 2013 15:32
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LV Aurora project (canceled project to launch Soyuz-derived LV from Christmas Island, Australia) included a Space Tug Korvet as a fourth stage of LV for GTO/GEO missions. Please note that Aurora was roughly equivalent to what became a Soyuz 2-3. Soyuz- 3 suppose to have bigger payload.
IMHO Block-DM for Soyuz-3 might be something between Korvet and Block-DM-SLB configurations.
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#2
by
zaitcev
on 26 Sep, 2013 17:19
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I don't think it's on the cards, for technical and economical reasons.
Firstly, Blok DM is quite tall, compared to Fregat. The fairing would be like Contravenes fairing of Atlas, thus expensive.
Secondly, Blok I contains the control system of the launcher.
Finally, Blok DM is produced by RKKE. I doubt that the level of cooperation required to fly Soyuz without Blok I is attainable. It's one thing when the launcher presents a clear interface to the payload, and another is this.
By the way, remember that Proton missions with Blok DM are more expensive than with Briz M. Same thing: RKKE changes arm and leg for DMs that they make.
To see where this is actually going, look at Volga being flown at Soyuz-2.1b instead.
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#3
by
Danderman
on 27 Sep, 2013 01:23
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I don't think it's on the cards, for technical and economical reasons.
Firstly, Blok DM is quite tall, compared to Fregat. The fairing would be like Contravenes fairing of Atlas, thus expensive.
Let me address the physical constraints here.
The absolute widest part of the Blok-DM is the base (3.9 meters). However, the lower half of Blok-DM does not have to be inside the fairing, since it carries its own aeroshell. Above the base of the Blok-DM, the maximum diameter is 3.7 meters.
The standard Soyuz-ST fairing, as used in Guiana, is 4.1 meters exterior, and 3.8 meters interior, so the Blok-DM would fit, except for the lower area that does not need to go inside the fairing.
As for height, the maximum height of Blok-DM from the lower to highest interface plane is 5.6 meters, although the nozzle of the main engine does stick down below that point. The Soyuz-ST fairing has about 8.1 meters of space above the Fregat separation plane to the top of the fairing interior. There is probably vertical space for Blok-DM plus payload in that fairing. Since we know that 3 Glonass can fit on Blok-DM, it is possible that 2 could fit and fly in this configuration.
I am thinking that a Soyuz 3/Blok-DM could fly 2 Glonass class payloads at a time to the Glonass reference orbit. Or 2 Meridian, maybe.
Of course, all the other issues are still unresolved, such as flying Soyuz with the Blok-I and the political problems with Energia effectively taking control of a Soyuz design. And yes, Blok-DM is expensive commercially, but here we are talking about a Russian government project.
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#4
by
fregate
on 27 Sep, 2013 02:58
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Last year Energia proposed to use Block-DM instead Centaur upper stage for LM Atlas LV, in order to decrease a mission price tug and fill a market void after decommission of Delta II LV.
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#5
by
Danderman
on 27 Sep, 2013 05:12
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Secondly, Blok I contains the control system of the launcher.
I completely forgot about this, but for many years, the standard Soviet launcher was the Vostok launcher, which had no Blok I. It in the 1970s when the Soyuz began taking over the workhorse role from the Vostok.
Another take on this is the Molniya launcher - was the control system for Molniya in the Blok I or the Blok L?
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#6
by
zaitcev
on 28 Sep, 2013 03:26
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The standard Soyuz-ST fairing, as used in Guiana, is 4.1 meters exterior, and 3.8 meters interior, so the Blok-DM would fit, except for the lower area that does not need to go inside the fairing.
(....)
Since we know that 3 Glonass can fit on Blok-DM, it is possible that 2 could fit and fly in this configuration.
Sounds reasonable, with only downside that you cannot reap benefits of discarding Blok DM's own lower fairing, as your original post suggested. On the upside, reusing an existing fairing is a plus, money-wise.
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#7
by
Danderman
on 28 Sep, 2013 05:26
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I am not suggesting that the Russians would ever use a Blok-DM in the configuration I am describing, only that it is a possible configuration for Glonass.
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#8
by
fregate
on 28 Sep, 2013 08:56
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Replacing Block I (LRE RD-0124 aka 14D23, thrust 30 tf) with Block-DM (LRE RD-58M with thrust 8 tf) would significantly change LV trajectory due to worth thrust to weight ratio.
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#9
by
Dmitry_V_home
on 28 Sep, 2013 10:09
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Monster!
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#10
by
Danderman
on 28 Sep, 2013 14:11
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Replacing Block I (LRE RD-0124 aka 14D23, thrust 30 tf) with Block-DM (LRE RD-58M with thrust 8 tf) would significantly change LV trajectory due to worth thrust to weight ratio.
Same as Vostok rocket, except that Blok-DM has more thrust than the Vostok upper stage.
Note that I am stipulating that the system requires that the core Soyuz stage use NK-33 or better main engine.
In many respects, however, this is similar in concept to the Atlas V/Blok-DM proposed by Energia.
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#11
by
Danderman
on 28 Sep, 2013 14:12
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Monster!
Not as bad as I thought it would be, thank you.
The point is to develop a Soyuz derivative that could launch 2 Glonass-class payloads at a time, ie, optimized for lower payloads to a higher orbit. Sort of the "Atlas-F" of Russia or a new "Vostok".
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#12
by
Dmitry_V_home
on 28 Sep, 2013 15:13
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Everything is bad. according to calculations to orbit of GLONASS it is put nothing
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#13
by
Danderman
on 28 Sep, 2013 17:12
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Everything is bad. according to calculations to orbit of GLONASS it is put nothing
Please show the numbers. It is possible that your assumptions and mine are different.
Also, please remember that the core stage of the Soyuz uses the NK-33 and is the same size as the Soyuz 2.1-V launcher, not the other Soyuz 2 variants. The NK-33 engine may throttle down. In fact, it occurred to me that using the NK-33 throttle capability, the existing Soyuz drop zones could be used for the boosters, whereas the core stage would fire for a very long time, and when it did drop, it would be at such a velocity and altitude that not much would return to Earth.
After separation of the 4 Soyuz boosters, we would have a 180 ton thrust engine firing for a couple of minutes, which is not too different from when the Zenit first stage is jettisoned, leaving the 95 ton thrust second stage to fire for some minutes; in both cases the payload is the Blok-DM plus satellite. In the case of this concept, the satellite(s) is 2 Glonass with a mass of 3 tons total. In the case of Zenit/Sea Launch, the payload is 6 tons.
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#14
by
Danderman
on 28 Sep, 2013 17:14
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The standard Soyuz-ST fairing, as used in Guiana, is 4.1 meters exterior, and 3.8 meters interior, so the Blok-DM would fit, except for the lower area that does not need to go inside the fairing.
(....)
Since we know that 3 Glonass can fit on Blok-DM, it is possible that 2 could fit and fly in this configuration.
Sounds reasonable, with only downside that you cannot reap benefits of discarding Blok DM's own lower fairing, as your original post suggested. On the upside, reusing an existing fairing is a plus, money-wise.
Here I made an error - my measurements for the Blok-DM lower section included the removable fairing. If the removable fairing were not used (since the Blok-DM would be under the Soyuz-ST fairing), then it is likely that the entire Blok-DM body would indeed fit under the Soyuz fairing. The requirement would be to gain 10 cm of diameter by removing the lower Blok-DM external fairing.
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#15
by
Dmitry_V_home
on 29 Sep, 2013 05:49
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Everything is bad. according to calculations to orbit of GLONASS it is put nothing
Please show the numbers. It is possible that your assumptions and mine are different.
Also, please remember that the core stage of the Soyuz uses the NK-33 and is the same size as the Soyuz 2.1-V launcher, not the other Soyuz 2 variants. The NK-33 engine may throttle down. In fact, it occurred to me that using the NK-33 throttle capability, the existing Soyuz drop zones could be used for the boosters, whereas the core stage would fire for a very long time, and when it did drop, it would be at such a velocity and altitude that not much would return to Earth.
After separation of the 4 Soyuz boosters, we would have a 180 ton thrust engine firing for a couple of minutes, which is not too different from when the Zenit first stage is jettisoned, leaving the 95 ton thrust second stage to fire for some minutes; in both cases the payload is the Blok-DM plus satellite. In the case of this concept, the satellite(s) is 2 Glonass with a mass of 3 tons total. In the case of Zenit/Sea Launch, the payload is 6 tons.
My calculations are made for "Soyz-2".
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#16
by
Danderman
on 29 Sep, 2013 15:08
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My calculations are made for "Soyz-2".
My initial assumption is that the Soyuz variant would use the NK-33 in the core stage; any Soyuz using NK-33 also uses the enlarged core stage (such as on the Soyuz 2.1v) with additional propellant.
I believe that the current designation for this minimum "enhanced" Soyuz is Soyuz 2-3, but that may have changed.
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#17
by
Danderman
on 29 Sep, 2013 15:34
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I don't think it's on the cards, for technical and economical reasons.
By the way, remember that Proton missions with Blok DM are more expensive than with Briz M. Same thing: RKKE changes arm and leg for DMs that they make.
According to the state contracts that Stan Black posts, the Briz M costs the government $12,963,729.08, and the Blok-DM-03 costs $13,161,185.20.
In other words, the prices of the latest versions of these two upper stage are virtually identical (for the Russian government).
To complete the analysis, I should not that Briz-M is NOT a candidate upper stage for this configuration - the engine thrust level is too low to offset gravity losses, and the stage would not fit under the 4 meter fairing.
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#18
by
baldusi
on 29 Sep, 2013 18:49
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But that's the cost of the stage, we don't know the rest of the costs. I doubt it, but may be the difference is in operations cost.
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#19
by
Danderman
on 29 Sep, 2013 22:23
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But that's the cost of the stage, we don't know the rest of the costs. I doubt it, but may be the difference is in operations cost.
My point here is the Russian government does not pay the same price as SeaLaunch does for the Blok-DM.
Therefore, the high commercial cost of Blok-DM is irrelevant when it comes time for the Russian government to determine whether a Blok-DM/Soyuz LV makes sense as a Proton replacement.
