Yangel Presents First (and the R-56 rocket flies)

[fasquardon]

In February 1962 Nikita Khrushchev organized a meeting of the USSR’s Defense Council with the main missile designers in the Soviet Union. In attendance were Chelomei, Korolev and, courtesy of Glushko's maneuverings, Mikhail Yangel. At stake was who would get to design the USSR's heavy lift rocket.

Chelomei would bring his ideas for a UR-500 rocket (eventually the Proton) and the monster UR-700.

Korolev would bring his ideas for the N-11 and N-1 rockets.

Yangel brought the R-36 (which became the Tsyklon launcher) and the R-56.

In OTL, Khrushchev would choose the N-1 as the Soviet heavy lift vehicle, the UR-500 as a medium lift vehicle/superheavy ICBM and the R-36 as an ICBM only. Yet, according to Sergei Khrushchev (son of Nikita and himself a rocket scientist), had Yangel been the first to present his designs, there was a very real chance that his father would have chosen the R-56 to be the Soviet Union's largest rocket.

So WI Yangel presents his designs first and Krushchev picks the R-56 for the heavy.

The first thought that occurs is what happens to the other rocket proposals. If Yangel wins the big ticket item, does the R-36 get developed (and if not, what fills the 1-2 tonne to LEO lift capacity that Tsyklon filled for the Soviets)? If Korolev doesn't sell the N-1 to Krushchev, does development of the N-11 get the green light? And if Korolev does get the N-11, does Chelomei get the UR-500 greenlit?

Personally, I would think that if Yangel gets the R-56 approved, he'd also get the R-36 approved and Chelomei would get the UR-500 approved, which leaves Korolev walking away from the meeting empty handed.

If that happens, it rather begs the question of what Korolev would do - no way he'd take it lying down. On the other hand, sunk-cost syndrome would make it difficult for Korolev to get the R-56 replaced by the N-1 (just as Yangel and Chelomei didn't succeed in displacing the N-1 in OTL), nor can I see Korolev getting the UR-500 replaced by the N-11. This may push Korolev to work more on the problem of assembling large space ships in orbit using multiple Soyuz launches (as per his original plans to reach the moon, which were abandoned once work on the N1 was approved) and to work more on improving the Soyuz rocket with better engines (perhaps working with Kuznetsov, as he had already while developing the R-9 missile, which could mean that even in a TL without the N-1, an engine like the NK-33 might still be designed) or with a high power LH2/LOX upper stage.

All of this could leave Yangel in a very strong position - he'd be the designer of the R-56, the favorite designer of the military men and the most important ally of Glushko (particularly since Glushko didn't like either Korolev or Chelomei). This could, almost by accident, lead to Yangel emerging as the most important chief designer until his death in 1971 as well as a more efficient distribution of resources within the Soviet space program.

It could also lead to a faster consolidation of the Soviet space program under Glushko after Yangel died, since in TTL, Glushko would have been the power behind both Chelomei and Yangel's rockets and Yangel's death is better timed for Glushko than Korolev's death was (since Korolev died just as the moon program was kicking into high gear, while Yangel's death would, IMO, either come after the moon program had actually gotten a man on the moon or just as the USSR was about to get a man on the moon).

Alternatively, it could lead to a much more prominent place for Vladimir Utkin after 1971. Since Yuzhnoye Design Bureau/OKB-586 produced the excellent Zenit rocket during Utkin's watch, I've always been curious what a more prominent place for him and OKB-586 in the 70s and 80s would have led to.

Finally, there's the question of what the R-56 would turn into in this TL. At the time of the PoD, the Soviets weren't really thinking of going to the moon. There's the chance that when Krushchev does decide to go to the moon in 1964, the R-56, like Korolev's N-1, could rapidly gain weight, becoming an oversized beast that was doomed to failure. Given that Yangel, unlike Korolev and Chelomei, didn't give in to the temptation to fatten the R-56 in the design studies produced during the early years of the moon program, I have hope that the R-56 would remain a rocket able to launch 40-50 tonnes to LEO and construct a moon ship in about 3 launches.

I'm curious how long people think the R-56 would take to develop. The Proton rocket took 3 years from the 1962 meeting to reach a flying state and another 11 years after that to fly reliably. Since the R-56 would be using the same first stage engines and the same propellant and technologies as the Proton, I would have thought it possible that the early stages could go well and the rocket could have its first successful flight somewhere in the 1965-1967 period. That may be optimistic though - larger rockets are always more difficult to make than smaller rockets. And much hinges on how soon the R-56 can be made reliable - most of the Proton's failures were of the upper stages - particularly the 2nd stage - since the R-56 used different engines for the upper stages, the rocket may prove more reliable than the Proton. There are no guarantees though.

Given how Yangel's other design efforts, I would expect the R-56 could be made reliable in time to get a Soviet man to the moon before the Apollo program ends and I'd say the Soviets have a decent chance at getting to the moon first with the R-56.

Either possibility opens all sorts of opportunities for both the Soviet and American programs.

References:

https://falsesteps.wordpress.com/2016/09/11/the-r-56yangel-works-for-us/
https://en.wikipedia.org/wiki/Mikhail_Yangel
http://www.bis-space.com/belgium/wp-content/uploads/2015/05/yangelrockets2.pdf
http://www.bis-space.com/belgium/wp-content/uploads/2015/05/yangelrockets1.pdf
http://www.astronautix.com/r/r-56.html

fasquardon

 

[fasquardon]

Also, it occurs to me that the R-56 with its 40-46 tonne to LEO payload would be a great LV for a mini-shuttle - say something a big bigger than Chelomei's OTL LKS design.

fasquardon

 

[fasquardon]

No-one have any thoughts? I would have thought this one would have real potential for a Soviet focused space TL.

fasquardon

 

[nixonshead]

Interesting question! Off the top of my head I'd suspect R-36/56 would put UR-500 out of business, but you'd think Chelomei would get something out of the meeting (Khrushchev Jr. needs something to keep himself busy). Almaz wasn't proposed until 1964, two years after your PoD, so not sure what he might propose.

Korolev would have Soyuz on the drawing board by this point, and given his success with Vostok and Voskhod would probably get to keep manned spacecraft. Would he be willing to quash his aversion to launching on hypergolics for larger missions? Maybe. He'd worked with Yangel in the 1950s, and they seem to have gotten on quite well, aside from their disagreement on storable propellants. Probably he'd go ahead with plans for Soyuz on R-7, maybe fleshing out his Soyuz-A concept for Earth orbit assembly missions, but keep N1 in his back pocket for when the decision comes a few years later to race the US to the Moon. At that point he'll certainly push for his large kerolox moon rocket, but the politics could see him put those Soyuz-A studies to work on a scaled-up EOR architecture launched by R-56.

Would Yangel have his own ideas for a manned spacecraft though? IOTL he seems to have been much more of a rocket guy than a spacecraft guy... but then again Glushko was an engines expert who delivered Energia/Buran, so we can't rule out something completely new. With Dynasoar dead and STS not yet approved, I doubt an LKS-style shuttle would get approved, but a Yangelised version of TKS could be a possibility. With R-56's greater lifting power, he (or Chelomei, working with Yangel) would be able to propose a larger space station for all those military space application that they didn't yet realise weren't worth doing.

Basically, I think this could be a great idea for a TL, with several plausible and very different outcomes giving lots of scope for creative freedom.

 

[fasquardon]

Khrushchev Jr. is a big reason I would expect the Proton to edge out the N-11. (The other reasons are the military benefits of storables and the way the Proton and R-56 can use many common components.)

Actually, I wonder if the R-56 being picked may mean the Proton emerges as a different rocket due to the higher-ups forcing Yangel and Chelomei to make their rockets use as many of the same components as possible?

__________

I wonder if Khrushchev could do something odd like approve the UR-700, the N-11 and the R-56. Or the UR-500, the N-1 and the R-56? I kind of doubt it, given that it seems that everyone seems to have seen the R-56 as a UR-700/N-1 alternative, rather than a medium size rocket. If the UR-700 got the approval, I could see it being good for the USSR, since they'd get the less toxic N-11 as their main heavy space booster and the UR-700 could well fail and the fruits of research into it could be folded into the R-56 (which would be launched far less and thus pollute less land and poison fewer people than OTL's Proton).

I doubt Khrushchev would approve a suite of rockets that were so heavy though.

__________

I wonder if it is plausible for Khrushchev to make a serious promise to Korolev or Chelomei that he would commit to racing the Americans to the moon as compensation for their not getting a rocket at this meeting.

I think Chelomei was the one most keen to go to the moon, so maybe we would get the N-11, the R-56, the R-36 and a moon program all in 1962. That would be a big deal!

__________

IOTL he seems to have been much more of a rocket guy than a spacecraft guy...

Then again, all of the chief designers seem to have preferred rockets - they were what made everything else possible and they were big prestige items. Certainly I've read that Yangel's bureau did excellent work on the lander for the Soviet moon landing.

__________

With Dynasoar dead and STS not yet approved, I doubt an LKS-style shuttle would get approved

I was thinking ahead to the mid 70s, if the US got interested in orbital spaceplanes in TTL (IMO very likely). Since in TTL, the Soviets very likely have the R-56 by '75, it is harder for Glushko or whoever else is running the show that they need to go straight for a giant space Winnebago like the US. The rocket capable of launching the LKS already exists, making it a much more appealing path.

fasquardon

 

[Archibald]

Once JFK commit NASA to the Moon, the Soviet Union is bound to have a symetrical answer sooner or later in the name of Cold War terror parity (what I called a dick-measuring contest, mine is bigger and so big it can reach the lunar surface. Meh.)
Now a lunar architecture using a couple of R-56 + EOR and LOR - I want to see that.

 

[Dathi THorfinnsson]

Now a lunar architecture using a couple of R-56 + EOR and LOR - I want to see that.

Heh. Have fun doing that with '60s era Soviet computing.

 

[fasquardon]

Heh. Have fun doing that with '60s era Soviet computing.

I thought the Soviets actually had more computing power applied to their ground operations than the Americans did in this period? Seem to remember that was a big reason why the Soviets took a lead in EOR operations in OTL.

Might be remembering that wrongly, but certainly Soviet computing was competitive in the 50s and 60s (and by competitive, I mean their designs compared favorably - I am pretty sure that they had far fewer computers available).

Now a lunar architecture using a couple of R-56 + EOR and LOR - I want to see that.

I'd REALLY like to see a lunar mission with EOR+LOR for the Soviets, mainly because I think that's their best bet to actually reach the moon. If they'd stuck with Korolev's original plan and build a moonship with Soyuz rocket launches ("Dawn of the Dragon" style), I reckon they could've had the first man on the moon by 1967 and saved a whole bunch of money developing all the N-1 gubbins.

Once JFK commit NASA to the Moon, the Soviet Union is bound to have a symetrical answer sooner or later in the name of Cold War terror parity

Khrushchev deciding to commit to the moon race in Feb 1962 would be a big change though. In OTL the Soviets didn't take the race seriously until 1964.

With a Feb 1962 commitment, I'd say even the N-1 might be ready in time to beat the Amerikanski to Luna.

(what I called a dick-measuring contest, mine is bigger and so big it can reach the lunar surface. Meh.)

An unmentionable so large it collapses under its own gravity... Now that would make an embarrassing visit to the doctor's office.

fasquardon

 

[nixonshead]

Heh. Have fun doing that with '60s era Soviet computing.

The Soviets managed fully automated docking in LEO as early as 1967 (Cosmos 166 and 168), so I'd see EOR at least being perfectly within their capabilities. LOR might be more complicated with less accurate ground-based tracking... but maybe not. I don't know if the LEO rendezvous used any ground data or were fully autonomous. If the latter, LOR is also doable.

I think they'd still have next to no chance of beating the US to the Moon (they started too late with too few resources in just about any likely timeline), but they might not be too far behind, and with an interestingly different approach.

 

[fasquardon]

The Soviets managed fully automated docking in LEO as early as 1967 (Cosmos 166 and 168), so I'd see EOR at least being perfectly within their capabilities. LOR might be more complicated with less accurate ground-based tracking... but maybe not. I don't know if the LEO rendezvous used any ground data or were fully autonomous. If the latter, LOR is also doable.

I think they'd still have next to no chance of beating the US to the Moon (they started too late with too few resources in just about any likely timeline), but they might not be too far behind, and with an interestingly different approach.

Well, I was thinking the "LOR" part would be as much "LOR" as Apollo had - namely, a separate lander that came to the moon in a package with the rest of the moon ship, then did a LOR and docked with the Earth return ship on the way back.

And I had gotten the impression that besides the N-1, all of the other hardware for a trip to the moon was well in hand - something which could only be helped by the weight limits being relaxed by the greater payload and flexibility of multiple R-56 launches (so, if the base mission is to use 3 launches, and the hardware goes overweight, it is easier to add a 4th R-56 launch than it is to fatten up the N-1).

Long story short, I would have thought that with a 1962 commitment, the Soviets would be well placed for a landing between 1967 and 1969. Certainly, I would have thought the Soviets would be first AROUND the moon in this scenario, since and earlier commitment to developing a larger capsule and a commitment to a bigger rocket would make the free-return trip the Soviets considered much more doable. If the program was able to promise a landing before 1971, I could see the political leadership being more enthusiastic about getting the first man into Lunar space as well, since "first man to the moon and close second to getting men ON the moon" is alot better than "first man to the moon and pathetically distant second to getting men ON the moon and do you call that dinky little pogo stick a lunar lander?"

I wonder how a somewhat successful Lunar program would influence Soviet rocket design? If they half-beat-half-lose the moon race with their smaller rocket or if they win comprehensively, it could make the Soviets much more confident that doing things their own way is better.

fasquardon

 

[fasquardon]

Here's a thought I've been having...

Let's say that by '73 the Soviet Launch Vehicle stable is the Soyuz, the Proton and the R-56. In this period in OTL, the politicians started getting interested in more environmentally friendly rockets (since Proton launches were dirty enough to worry even Soviet politicos in the 70s) - in this ATL, I am guessing that the Soviets would be similarly keen to make things cleaner. In OTL, the big contenders were what became the Zenit (from Yangel's own Yuzhnoye Design Bureau) - a modular rocket that could handle payloads from the Soyuz scale up to 60 tonnes to LEO - and Glushko's modular heavy rockets. In OTL the two proposals were merged and became Zenit and Energia (which was partially composed of Zenit first stages).

If Yuzhnoye Design Bureau already has the premier Soviet rocket and Korolev had been working more on upgrading the Soyuz rocket, would there be so much interest in new rockets in the SU? Would the Yuzhnoye team follow Chelomei's path and offer a ker/LOX version of the R-56 to the Politburo? Or would they offer something like the Zenit regardless?

And how practical is it to actually change a hypergolic rocket to a ker/LOX rocket? What I've read is that it would be trivially simple and require only minor changes - but I'm pretty sure what I've read was written by biassed chief designers who wanted to make sure their own projects got funded. So far as I am aware, no hypergolic rocket has been redesigned to burn ker/LOX.

fasquardon

 

[fasquardon]

And how practical is it to actually change a hypergolic rocket to a ker/LOX rocket? What I've read is that it would be trivially simple and require only minor changes - but I'm pretty sure what I've read was written by biassed chief designers who wanted to make sure their own projects got funded. So far as I am aware, no hypergolic rocket has been redesigned to burn ker/LOX.

Anyone have any idea what the answer to this question is?

fasquardon

 

[e of pi]

Anyone have any idea what the answer to this question is?

fasquardon

I'd describe it as neither impossible nor trivial. The mixture ratio is different, so the relative lengths of the tanks need to be altered, and LOX requires insulation NTO doesn't. Titan made the inverse switch--kerolox to hypergol--but I'm not really aware of anyone going the other way. Given the issues hypergol costs presented for Ariane and Titan, you'd think if it was "trivial" those rockets would simply have switched instead of developing entirely new replacements. I suspect that answer is that it's much more practical on paper than in practice, and in reality by the time you do it it's hard enough that it makes sense to make other small changes like new materials, tooling, and engines, new upper stages, and maybe a new diameter...and pretty soon it's a whole new LV.

EDIT: Running some numbers, starting with NTO/UDMH like the R-56 was to us, you need to change from the oxydizer tank being about 54% of the combined volume to about 62% of the combined volume. Worse, the combined density of kerolox is only 87% that of the NTO/UDMH, so your liftoff mass will drop by 13% unless you also stretch the tanks. Then you have to insulate the LOX, and deal with the added dry mass of more tank and the insulation. It's not impossible, but it's not trivial, and by the time it's over it'd be perhaps the same diameter, but overall a dramatically new rocket.

 

[Dathi THorfinnsson]

I would imagine that the turbopumps and engines and stuff need a bit of work, too.
Since UDMH can be used as a monopropellant, I'd suspect that that's used to power both sets of pumps, whereas LOX/Kerosene you need to pre-burn some fuel... No?

 

[fasquardon]

I would imagine that the turbopumps and engines and stuff need a bit of work, too.
Since UDMH can be used as a monopropellant, I'd suspect that that's used to power both sets of pumps, whereas LOX/Kerosene you need to pre-burn some fuel... No?

The RD-253 used staged combustion, so that element of the design would be the same. 'Course the combustion chamber may need to be altered and the turbine alloy may need changing...

I'd describe it as neither impossible nor trivial. The mixture ratio is different, so the relative lengths of the tanks need to be altered, and LOX requires insulation NTO doesn't. Titan made the inverse switch--kerolox to hypergol--but I'm not really aware of anyone going the other way. Given the issues hypergol costs presented for Ariane and Titan, you'd think if it was "trivial" those rockets would simply have switched instead of developing entirely new replacements. I suspect that answer is that it's much more practical on paper than in practice, and in reality by the time you do it it's hard enough that it makes sense to make other small changes like new materials, tooling, and engines, new upper stages, and maybe a new diameter...and pretty soon it's a whole new LV.

EDIT: Running some numbers, starting with NTO/UDMH like the R-56 was to us, you need to change from the oxydizer tank being about 54% of the combined volume to about 62% of the combined volume. Worse, the combined density of kerolox is only 87% that of the NTO/UDMH, so your liftoff mass will drop by 13% unless you also stretch the tanks. Then you have to insulate the LOX, and deal with the added dry mass of more tank and the insulation. It's not impossible, but it's not trivial, and by the time it's over it'd be perhaps the same diameter, but overall a dramatically new rocket.

OK. Sounds like a world with the R-56 is a world that still has Zenit and perhaps something very like Energia in it (though if the US doesn't opt for a shuttle in this TL, it may be a much smaller Energia).

fasquardon

 

[RanulfC]

fasquadron wrote:

And how practical is it to actually change a hypergolic rocket to a ker/LOX rocket? What I've read is that it would be trivially simple and require only minor changes - but I'm pretty sure what I've read was written by biased chief designers who wanted to make sure their own projects got funded. So far as I am aware, no hypergolic rocket has been redesigned to burn ker/LOX.
Anyone have any idea what the answer to this question is?

E of pi wrote:

I'd describe it as neither impossible nor trivial. The mixture ratio is different, so the relative lengths of the tanks need to be altered, and LOX requires insulation NTO doesn't. Titan made the inverse switch--kerolox to hypergol--but I'm not really aware of anyone going the other way. Given the issues hypergol costs presented for Ariane and Titan, you'd think if it was "trivial" those rockets would simply have switched instead of developing entirely new replacements. I suspect that answer is that it's much more practical on paper than in practice, and in reality by the time you do it it's hard enough that it makes sense to make other small changes like new materials, tooling, and engines, new upper stages, and maybe a new diameter...and pretty soon it's a whole new LV.

EDIT: Running some numbers, starting with NTO/UDMH like the R-56 was to us, you need to change from the oxydizer tank being about 54% of the combined volume to about 62% of the combined volume. Worse, the combined density of kerolox is only 87% that of the NTO/UDMH, so your liftoff mass will drop by 13% unless you also stretch the tanks. Then you have to insulate the LOX, and deal with the added dry mass of more tank and the insulation. It's not impossible, but it's not trivial, and by the time it's over it'd be perhaps the same diameter, but overall a dramatically new rocket.

To be more detailed, the Titan I LR87 engine ran on kerolox which was then switched to Aerozine-50 (50/50 mixture of hydrazine and UDMH)/N2O4 after some modification. What is even more interesting is the LR87 was also modified and tested as an LH2/LOX engine and appears to have "lost" to the J2 for use in the Saturn series by missing one (1) criteria. (Reference doesn't say what that was, but my guess would be thrust)
https://en.wikipedia.org/wiki/LR-87

And it should be noted that the growth/later version of the R56 was to be switched from the RD253 to the RD270. Worse come-to-it how tough would it be to switch to the RD170 when it becomes available?

One thing that has always bugged me is that the Soviets were very conservative in a lot of ways and tended to stick with something till forced to change. They didn't really push ahead with LH2 engines till they absolutely had to but they did tend to do a lot of one-off and test programs that promised much but were never pursued. Conversely they tended to take risks they didn't have to in order to achieve some goals but then turned right around and refused to take other risks that seemed lesser or with bigger payoffs.

(All that work and they never seemed to have stumbled across liquid methane or sub-cooled propane as propellants that were easier to work with than LH2 and better performing than storables or kerosene???)

Understandable in general I guess but it makes me wonder how possible a certain scenario I've had in mind is. (How does this relate? Let me 'splain ) Well in THIS scenario with the R-56 and possibly Proton available it still looks like the US would probably be first to land on the Moon but would it be possible to suggest that landing first, while a laudable and PR goal, may not be as important as who stayed? (Or at least stayed the longest?)

Would there be, could there be support for pulling a "Project Pilgrim" to if not beat the American's to the Moon show the Soviets were perhaps more 'serious' than the Americans about space?
https://www.wired.com/2012/04/one-way-space-man-1962
https://en.wikipedia.org/wiki/Countdown_(1968_film)
http://spacebookspace.blogspot.com/2009/06/pilgrim-project-hank-searls.html
I have my doubts it would be plausible, further I think the amount of hubris, and assumed superiority in the American case to let the Soviets set up the details is possible I doubt they'd get away with it. But really what could the American's do if the Soviets actually tried it?

Randy

 

[fasquardon]

Would there be, could there be support for pulling a "Project Pilgrim" to if not beat the American's to the Moon show the Soviets were perhaps more 'serious' than the Americans about space?

I could imagine the Soviets trying to push for a lunar shelter with maybe a 1 month stay for two people. Project Pilgrim just seems outrageously risky for the 1970s and I doubt the Soviets would be willing to take such a risk so publicly.

Having read more about the costs estimated for the Soviet moon base plans, I can't see the Politburo ever signing off on such plans - or at least not until the Soviet Union was much richer than it ever got in real history.

And it should be noted that the growth/later version of the R56 was to be switched from the RD253 to the RD270. Worse come-to-it how tough would it be to switch to the RD170 when it becomes available?

I can't see Glushko getting the funds to develop the RD170 unless they were building a bigger rocket, which may mean the R-56 would lose its niche. But even if the Soviets had the RD-170 available and re-engined the R-56 with it, would that be an efficient way to go? By the 1980s (I don't see the RD-170 being available earlier), the Soviets had better manufacturing techniques, particularly for the tanks, and the pad infrastructure and where the fuel and oxidizer ports were located may need to change...

One thing that has always bugged me is that the Soviets were very conservative in a lot of ways and tended to stick with something till forced to change.

Hmm. I thought they tried to change too often myself. They had lots of nice paper rockets and partially developed rockets but relatively few finished rocket designs.

(All that work and they never seemed to have stumbled across liquid methane or sub-cooled propane as propellants that were easier to work with than LH2 and better performing than storables or kerosene???)

Given the infrastructure of the day, I can understand why they didn't choose methane - Meth/LOX makes alot more sense now we have a large LNG infrastructure. As for propane, yes, I wonder about that too. I am guessing that bang for development buck is an issue though - kerosine was already an extensively used aviation fuel and LH2 offers much higher ISPs than anything short of nuclear propulsion.

fasquardon

 

[RanulfC]

I could imagine the Soviets trying to push for a lunar shelter with maybe a 1 month stay for two people. Project Pilgrim just seems outrageously risky for the 1970s and I doubt the Soviets would be willing to take such a risk so publicly.

Actually it was never name "Project Pilgrim" outside of the book/movie, and the fact it WAS 'officially' named the "One Way" mission would in no way have provided a 'warm-fuzzy' feeling of expanding mankind's frontiers...

Pretty much the exact same reason suggesting the same thing for Mars has fallen flat

However, there is a fine line between "outrageously" and "desperate" which one must admit made the book/movie plausible if not likely. The hard to differentiate part is the plan really, really, really is NOT a 'suicide' mission and IF you are going to do it you CAN in fact build in several places where you can not go if things are not just right. But to get to the point where the "reward" outweighs the "risk" would take some justification that is probably unlikely.
On the other gripping hand though given the way the Soviet's operated their space program they could actually have gotten pretty far along before they had to make a go/no-go decision and no one would find out about it.

Having read more about the costs estimated for the Soviet moon base plans, I can't see the Politburo ever signing off on such plans - or at least not until the Soviet Union was much richer than it ever got in real history.

Actually there's the rub as it were; This would have cost on par to several lunar LANDING missions but not as much as any proposed 'base' plan until and unless they decided to proceed with expanding and developing an actual base. It could be pitched as cheaper than any of the base proposals and not much more expensive than the lunar landing proposals and argued on those grounds. But as we both agree someone as to be really desperate, very early on for it to be plausible which is unlikely.

I can't see Glushko getting the funds to develop the RD170 unless they were building a bigger rocket, which may mean the R-56 would lose its niche. But even if the Soviets had the RD-170 available and re-engined the R-56 with it, would that be an efficient way to go? By the 1980s (I don't see the RD-170 being available earlier), the Soviets had better manufacturing techniques, particularly for the tanks, and the pad infrastructure and where the fuel and oxidizer ports were located may need to change...

Depends I suppose on where they are planning on going and the justifications thereof. Under the assumption they are going to either switch propellant at some point OR build a new rocket I guess it comes down to which seems the better choice at the time of the decision. The circumstances are going to be the major decision factors and those in turn depend on what both the USSR and US are doing at the time.

Hmm. I thought they tried to change too often myself. They had lots of nice paper rockets and partially developed rockets but relatively few finished rocket designs.

I got the idea that was BECAUSE while they were interested in options when it came down to it they choose to retain and modify rather than build new. When they DID decide to build something new they tended towards fully different designs that were less supportable than the older designs. They never seemed to develop long-range plans and changes seemed to come in spurts and only when they had no other choice. YMMV

Given the infrastructure of the day, I can understand why they didn't choose methane - Meth/LOX makes alot more sense now we have a large LNG infrastructure. As for propane, yes, I wonder about that too. I am guessing that bang for development buck is an issue though - kerosine was already an extensively used aviation fuel and LH2 offers much higher ISPs than anything short of nuclear propulsion

I was under the impression that the USSR had a relatively better Natural Gas system than Europe or North America earlier? And while LH2 offers the higher ISPs and kerosene was available the latter was significantly lacking in performance they needed while the former was going to be expensive and difficult given their general development issues. Having said that it pays to keep in mind that in the US we actually learned about the real world performance of a lot of propellants rather than the 'theoretical' performance only because someone decided to see what happened and we had the RL10 to do it with
(Seriously, you get an impression from what you can find, and it's hard in and of itself, that alcohol may not have been tried as a fuel in it but it WAS involved with some of the decisions on what to run through an RL10 and see if it worked. I mean I get boron, aluminum, and even fluorine but some of those early HEDM combinations HAD to rip up some turbopumps on a regular basis! )

What is odd however is apparently while arriving at LOX/SCPropane is pretty 'obvious' when working from an LH2/LOX 'gas-gas' combustion aspect, it also is pretty obvious if you work it from the Kerosene/LOX "liquid/fine-mist-gas" combustion angle but by the time this was 'evident' in US research we were well on the way to producing working LH2/LOX engines anyway so it wasn't pursued outside of testing. (And technically we already HAD a working LH2/LOX engine in modifications of the Titan LR87 engine, which is ANOTHER thing the Soviet's appeared to miss both intelligence wise and internal) I found little evidence that the Soviet's did as much "see-what-happens" testing at the US did, (and I suspect both economic and aversion to change factors here) and not a whole lot of work in general outside of kerolox, hydrolox, and storable propellant lines.

As I pointed out LNG seems a rather obvious choice, but the 'kicker' in the case of SCpropane is how much more 'bang' you get with no major changes in technology from kerolox to SCpropane/LOX. In most cases you literally get significant efficiency gains in the same space as kerosene. You have to add insulation to the kerosene tanks but that can be external and apparently you have a lot less combustion and injector design issues for the engine.

So while I can easily see little or no US interest, (in fact it was suggested for a number of concepts in military and civilian circles about 10 years ago but faded as methane got more popular) but not why no one in the USSR even considered it. Funny.

Randy

 

[fasquardon]

I was under the impression that the USSR had a relatively better Natural Gas system than Europe or North America earlier?

Yes. But that NG system was built mostly in the 70s (to exploit the Caucasian gas fields) and the 80s (to exploit the Siberian gas fields). And I know that for the Siberian system, a heck of alot of the infrastructure had to be imported from the West (large diameter pipes were a particular issue - the Soviets could have produced their own pipes, had they first built the factories needed, but Brezhnev had decided to rush completion).

As far as propane as a fuel, I found an interesting article here. This is the most interesting section:

The light alkanes are all readily available in industrial quantities,
are good coolants. Going from RP-1 to methane gains 3.8 % in Isp, but
costs about 22% in density. Other alkanes lie between the performance
of methane and RP-1.

Propane at room temperature is a non-starter for pump fed engines, as
its vapor pressure is too high for light weight tanks. Propane is
unusual in that it will not freeze solid if put in tanks in thermal
contact with LOX tanks; it has been proposed therefore to use sub-cooled
propane. Calculations done here show both propane at its normal boiling
point, and at 100 K, about 10 K above LOX temperature. Sub-cooled
propane (at LOX temperatures or slightly above to account for imperfect
chilling of propane by adjacent LOX tanks) is a winner, with a bulk
density nearly the same as that of RP-1, and a superior Isp.

The light unsaturated compounds are also readily available in industrial
quantities. These compounds may possibly give polymerization problems
when used for engine cooling, but again, they may not (particular those
which are very cold to start with may not warm up enough to cause
problems). They don't seem to be superior enough to alkanes to make
their use worth while, particularly considering that they generally have
higher chamber temperatures than for alkanes with the same Isp.

So it looks like replacing the kerosene with supercooled propane means pad infrastructure would need to change, the kerosene tank would need to be insulated insulated and the rocket engines must take the higher chamber pressure (depending on the engine involved this could be more or less of a problem). I don't think that would be a huge deal for an upgrade program. And the upgrade would mean losing some of the disadvantages of kerosene. The issue seems to be more that propane has never been enough of an improvement to be worth implementing.

Heck, much of the reason why methane is gaining traction now is because we are running out of sources of good rocket kerosene and because methane is relatively easy to synthesize using biological and non biological processes. Though I think there is an ISRU pathway that most efficiently produces propane - or maybe it was butane...

fasquardon

 

[RanulfC]

Yes. But that NG system was built mostly in the 70s (to exploit the Caucasian gas fields) and the 80s (to exploit the Siberian gas fields). And I know that for the Siberian system, a heck of alot of the infrastructure had to be imported from the West (large diameter pipes were a particular issue - the Soviets could have produced their own pipes, had they first built the factories needed, but Brezhnev had decided to rush completion).

Ok, I was misremembering the decade I guess

As far as propane as a fuel, I found an interesting article here. This is the most interesting section:

Dr. Dunn on scispace IIRC, from yarchives I suspect?

If you can find his "Propellants for SSTO Application" which expands and better quantifies that post is an excellent primer, (I can't find it since Dunn Engineering went away but it may be in archive-land) along with the always interesting: http://www.osti.gov/scitech/servlets/purl/379977, which inspired both Dunn and Clap, (of Blackhorse fame) to look beyond the 'hydrogen hype' as it's been called. Some links for you:
http://yarchive.net/space/rocket/fuels/hydrogen_deltav.html (note there's a text version of a Mitchel Clapp paper here on a possible kerolox SSTO here)
http://yarchive.net/space/rocket/fuels/hydrogen.html

And of course I think the most 'telling' indicator was of course cultural. In context, an off-handed comment by one rocket engineer concerning the 'poor' performance of late 1950s rockets was to say "You just wait until we get hydrogen rockets" as thought that would solve everything. And that's pretty much what non-technical and popular articles, talks and books by those same scientist was saying in that 'anything' would be possible as soon as we had hydrogen rocket engines. And they of course had the math/theory to prove it with Single Stage to Orbit vehicles and regular passenger flights every day to every corner of the globe by ballistic rocket! (Not to be confused with an ICBM because, well who would make THAT mistake? ) Of course these are basically the same folks who simply looked at the math for SCramjets, (which said once combustion went supersonic there was no point where you couldn't keep burning fuel and accelerating) and brushed of the actual design work as "trivial" so I suppose it stands to reason...

But I'm getting "blog-y" as my wife says so back to the subject at hand.

So it looks like replacing the kerosene with super-cooled propane means pad infrastructure would need to change, the kerosene tank would need to be insulated and the rocket engines must take the higher chamber pressure (depending on the engine involved this could be more or less of a problem). I don't think that would be a huge deal for an upgrade program. And the upgrade would mean losing some of the disadvantages of kerosene. The issue seems to be more that propane has never been enough of an improvement to be worth implementing.

"Super-cooling" to LOX temperatures as compared to Liquid Hydrogen, or Methane. Think about that for a second, and then note it's far denser than either of those. If all you're doing is "comparing" and going with the higher ISP then obviously hydrogen wins every time. Methane is a distant second and nothing else is going to be considered. Which, (hey look!) is exactly what happened pretty much everywhere OTL. You 'start' with kerosene and/or storable propellants and then move to hydrogen and never look back because why should you? And especially if the "big" boys are all doing it

The only program that didn't fall in line initially was Great Britain and even they eventually went kerolox even though keroxide was arguable, (and it was argued) operationally and economically better in the short term. But the Soviets and US pretty much drove everything till the mid-90s.

Heck, much of the reason why methane is gaining traction now is because we are running out of sources of good rocket kerosene and because methane is relatively easy to synthesize using biological and non biological processes. Though I think there is an ISRU pathway that most efficiently produces propane - or maybe it was butane...

Actually, believe it or not, propane was 'considered' seriously in the 70s while around the same time LH2 was being considered and studied as a possible commercial fuel. Several studies went into great detail on 'dual-fuel' propellant rockets using LH2 and propane, (sub-cooled but it's really not obvious in the text or figures) specifically to address two of LH2 problems; bulk and storage.

While NASA and the private sector were looking to LH2 for things like aircraft and vehicle fuel the military had already decided that operationally LH2 wasn't a good prospect and they went from propane to methane in quick succession. Funny enough the exact reason was that while propane was available since the idea was to look beyond petroleum and it's byproducts it was clear that a 'hydrogen' economy would be based on natural gas and not actual initial hydrogen production such as electrolysis. So logically the idea was to cut out the step where you turned natural gas into hydrogen since you weren't planning on using hydrogen anyway

That pretty much went away at the same time the 'hydrogen economy' for the commercial and general use did but it was still mentioned in the 'industry' for various purposes, including propulsion. And then Zubrin came up with "Mars Direct" and ISRU for methane, (it was actually 'suggested' as far back as 1962 but forgotten over and over again, http://spaceflighthistory.blogspot.com/2015/08/the-martian-adventure-forgotten-pioneer.html) and its been ramping up ever since. ISRU propellant making is a bit convoluted simply because everyone has an opinion, and the facts/math to back them up!

Thing is you have to look at the whole system rather than just what's easier to make and there things get complicated. The Sabatier process is pretty straight forward for methane but people tend to skip over the fact that it produces hydrogen peroxide about as good as it does oxygen for LOX and you don't have to cryo-cool that. On the other hand H2O2 and just about anything other than kerosene if crappy rocket propellant, so LOX makes sense for the most part. Similarly ethelyne (IIRC) was probably the most direct producible propellant but again you have the ISP issues and the main issue of someone having actually built and run a rocket on it. (Not so much of a problem these days but anytime before the early 2000s, other than test engines no one was really branching out) Got some good links here if you want to know more: http://forum.nasaspaceflight.com/index.php?topic=24928.msg730201#msg730201

Heck the whole site is great

Anyway it all comes down to the standard "Alternate History" beginning, "what if someone had done something different?"

Randy