"Certainly the 'Buran-Energiya' system is the more effective space complex. But it is necessary to remember that "Buran" was created after 'Space-Shuttle' with a break of more than 5 years. It has allowed on one hand to apply more modern methods of designing, materials, manufacturing technologies, test methods etc. and to another - has enabled our designers to take into account all foreign miscalculations and mistakes.The on-board system was also created as an improved in comparison with the existing American shuttle. "
Energia/Buran could haul more payload, and had a built-in non-orbiter cargo capability that NASA was never able to develop. That's the "superior" part.But I'm comfortable saying, based on the history of RD-171 and Zenit for starters, that Energia would not have been safer than Shuttle. As for the ice/foam thing, wouldn't Energia have presented the same hazard to Buran TPS? Maybe even more since the boosters would also have shed ice. - Ed Kyle
I suspect that ice falling off the boosters would not have been that big of an issue. After all, we never lost an orbiter to ice, but we did lose one to foam coming off the external tank. I was under the impression that the Energia's core did not feature foam that could fall off like on the Shuttle's ET. Perhaps this would be one alleged superiority of the launch system Molniya is talking about. It certainly appears that's the case when you look at what launch footage is available. The only thing I see coming off the launcher seems to be ice, which surely would be less dangerous than foam.
It's true that the Energia rocket was only launched twice, and the Buran shuttle only launched once with it. This however has more to USSR's economic collapse than the merits of the design. But I've always wondered, had the USSR not economically collapsed, would the Energia launcher and Buran shuttle have proved the superior, safer designs? The Shuttle and STS after all has killed some 14 astronauts in two separate disasters due to design flaws the Energia/Buran system did not have. To the best of my knowledge, the Energia launcher lacked the falling foam problem that came with the shuttle's external tank, which later would doom Columbia. The Energia launcher also was an all-liquid engine design, so it lacked the o-ring issues on the SRBs that in 1986 would claim the shuttle Challenger shortly after lift-off. Yet the alleged superiority of the Energia/Buran does not end there. 1) Energia could be launched without the Soviet space shuttle.2) Soviet Space Shuttle could haul 5 mt more into LEO (thanks to not carrying the heavy main engines). 3) The Buran could supposedly be more easily refurbished for flight thanks to not carrying large engines. 4) The Buran demonstrated it could be flown unmanned, which was never demonstrated by the Shuttle. 5) The Buran had an automatic docking system, the Shuttle did not. 6) The Energia was modular and had far more lift capability (88 mt) compared to an equivalent STS cargo variant (70 mt). 7) With additional boosters and an upper stage, the "Vulkan Herkules" version of the Energia could have lifted 200 mt into LEO, which dwarfs the capability of even the Saturn V. On and on the list of alleged advantages go...But I've always wondered whether Valentin Glushko's setup was really safer than STS, having seen the numerous explosive first-stage failures of Zenits over the years. What I think is incontrovertible is that the Energia/Buran system was certainly more capable and flexible, and would have been able to much more easily transition to BEO manned spaceflight compared to the STS. But at the end of the day, was the Energia/Buran setup ultimately superior and safer than the Shuttle/STS? What do you think of Molniya's claims of the Energia/Buran setup being the superior design, is it chest-thumping or backed by the facts?
Quote from: Hyperion5 on 03/15/2013 03:29 PMI suspect that ice falling off the boosters would not have been that big of an issue. After all, we never lost an orbiter to ice, but we did lose one to foam coming off the external tank. I was under the impression that the Energia's core did not feature foam that could fall off like on the Shuttle's ET. Perhaps this would be one alleged superiority of the launch system Molniya is talking about. It certainly appears that's the case when you look at what launch footage is available. The only thing I see coming off the launcher seems to be ice, which surely would be less dangerous than foam. HUH? Ice is much more dangerous than foam. That is why the foam existed in the first place was to prevent ice. Look at LO2 tanks on launch vehicles, they don't have foam because they are not worried about ice.
Quote from: Hyperion5 on 11/25/2012 05:44 PMThere's also the Atlas V, which looks likely to start sending up American astronauts in a few years' time. Its RD-180 engine, unlike the RD-171, has proven extremely reliable. It has proven so reliable that ULA floated plans of an Atlas V Phase 2 with the exact same number of engine chambers as the Zenit. Yet with two RD-180 engines why doesn't ULA even appear to blink at the dangers of "catastrophic failures" you mention? Why would they even consider an Atlas V Phase 2 Heavy with six of those engines (12 engine chambers and considerably more turbopumps) on three cores? The answer, I think, is that dual RD-180 engines is a more reliable and safer setup than one RD-171. Wrong. The reason they use RD-180 for advanced designs is because they have a source for engine.RD-17X problems have nothing to do with the number of chambers. It has to do with manufacturing quality.
There's also the Atlas V, which looks likely to start sending up American astronauts in a few years' time. Its RD-180 engine, unlike the RD-171, has proven extremely reliable. It has proven so reliable that ULA floated plans of an Atlas V Phase 2 with the exact same number of engine chambers as the Zenit. Yet with two RD-180 engines why doesn't ULA even appear to blink at the dangers of "catastrophic failures" you mention? Why would they even consider an Atlas V Phase 2 Heavy with six of those engines (12 engine chambers and considerably more turbopumps) on three cores? The answer, I think, is that dual RD-180 engines is a more reliable and safer setup than one RD-171.
Btw Jim, about Ed's point on the RD-170 engines' design being problematic, I seem to recall you commenting that it had more to do with manufacturing quality than design. ...snip...So if the problem was with manufacturing quality, and they went all out on that with the RD-170 engines for the Energia's boosters, which I imagine they did, would that have been enough to give RD-180 like reliability?
Quote from: Hyperion5 on 03/15/2013 04:21 PMBtw Jim, about Ed's point on the RD-170 engines' design being problematic, I seem to recall you commenting that it had more to do with manufacturing quality than design. ...snip...So if the problem was with manufacturing quality, and they went all out on that with the RD-170 engines for the Energia's boosters, which I imagine they did, would that have been enough to give RD-180 like reliability? Regardless, as long as it was the Soviets building the boosters, you'd have those manufacturing quality issues. Who's to say the failures were the result of specific engine problems?I don't think it was the NK-33's that caused the failures of the N-1's specifically, but other quality issues of the N-1.
Alright, so it's much more dangerous, but the point stands that we lost an orbiter to the foam meant to prevent the ice, not the ice. So yes, in theory Jim, the ice is much more dangerous, but it's not what did in the Columbia. Can you name me another time when ice on the ET endangered a mission versus foam?
Buran superior to Shuttle? "Superior" in what sense?If economically, then on that metric almost anything is "superior" to Shuttle.
Shuttle was more economical than Titan IV, especially considering it could carry the same amount of cargo plus a crew, which would require a separate Titan flight.
Quote from: gospacex on 03/15/2013 05:32 PMBuran superior to Shuttle? "Superior" in what sense?If economically, then on that metric almost anything is "superior" to Shuttle.Buran was so economical it was never flown again.Shuttle was more economical than Titan IV, especially considering it could carry the same amount of cargo plus a crew, which would require a separate Titan flight.
Well, ďsuperiorĒ I think is too strong. The Soviets basically copied all of NASAís hard work developing the shuttle for it. They made some better choices I think, as they didnít have the political climate NASA had. Their directive was, ďGive use parity to the American Capitalist pigs as soon as you canÖlearn what you can from the work theyíve already doneÖthis is the money and assets you have to work withĒ. Where NASAís was, ďGives us a brand new Reusable Space plane never seen by the world before, that is a fully reusable system, or as close to it as possible. Spread the work all round the country so that Congress is happy with it. It must have a 60ft X 22ft payload bay.ĒI donít know that the Soviets had stolen the actual plans for the shuttle, but there was enough public knowledge about itís metrics that it gave the Soviets a pretty good place to start rather than having to start from scratch like NASA did. They didnít have access to make large solids like we did, so they went with what they had available. But that was a good move in itís own right, and NASA would have been much better off using existing assets rather than developing brand new reusable boosters. But NASA didnít have any reusable boosters assets, and the focus of the program was on reusability, and it was thought that reusable liquid boosters would take too long. Thus the 4-seg SRBís. The Soviets didnít care about reusing the boosters or main engines, so that influenced their changes and the assets they had available. The auto docking and auto landing capability might have just been a product of it being a later design than the Shuttle. I donít know.
The reason the SSMEís were on the orbiter was for reusability, but then that made it impossible for the stack to launch without the orbiter. So thatís hard to really say if Buran was superior. If the SSMEís had turned out to be very cheap and easy to refurbish, then we might have looked at the expendable RD-0120ís as wasteful and inefficient. Same with the booster. The fact that the SSMEís ended up costing not more to save and refurbish than making new, as was with the SRBís, was a hindsight perspective. You might say it ended up being better to do it the way Buran did by ďaccidentĒ. Reusability wasnít the cost saver we hoped, and expendability wasnít the liability we thought it would. I think if either NASA or the Soviets had evaluated the Buran and Shuttle designs before either of them had been built, the consensus might have been that the Shuttle was better due to itís more reusable elements, and Energyia/Buran would be more expensive and inefficient.
Buran/Energyia I believe didnít have those reusable elements because they really couldnít, or couldnít in the time and money limits they were given to give the Soviet Union space parity with the US. Energyia and Buran were more simple designs by using hydrolox and existing booster engines that didnít have any reusability criteria, and a MPS that was inline to the core, rather than placed in the orbiter. And those turned out to be better in the long run, more by accident than design.
The American shuttle design was studied intensively by Russian rocket scientists, but important aspects of it were rejected based on Soviet engineering analysis and technology:The Soviet Union at this point had no experience in production of large solid rocket motors, especially segmented solid rocket motors of the type used on the shuttle. Glushko favored a launch vehicle with parallel liquid propellant boosters. These would use a 700 metric ton thrust four-chamber Lox/Kerosene engine already under development.The high chamber pressure, closed-cycle, reusable 230 metric ton thrust Lox/LH2 main engine being developed for the shuttle was well outside engineering experience in the Soviet Union. No engine using these cryogenic propellants had ever been used in Russian rockets, and the largest such engine under development was the 40 metric ton thrust 11D57. Glushko believed that while a Soviet cryogenic engine of 200 metric tons thrust could be developed in the required time, to develop a reusable engine would be impossible due to limited experience with the propellants.This conclusion led to other important design decisions. If only expendable engines were to be used, there was no need to house them in the re-entry vehicle for recovery. This meant that the orbiter itself could be moved from the lateral mounting of the space shuttle to an on-axis position at the top of the rocket core. The result was the Vulkan - a classic Soviet launch vehicle design: booster stages arranged around a core vehicle, with the payload mounted on top. The elimination of the lateral loads resulted in a lighter booster, and one that was much more flexible. The vehicle could be customized for a wide range of payloads by the use of from two to eight booster stages around a core equipped with from one to four modular main engines. Either a payload container for heavy payloads (Glushko's LEK lunar base) or the military's required spaceplane could be placed on the nose as the payload.As far as the manned orbital vehicle itself, three different primary configurations were studied extensively, as well as a range of more radical proposals. The final choice was a straight aerodynamic copy of the US shuttle.
I donít know about the foam shedding issues. How did the Soviets address it? Their core was still hydrolox, so it would have still had to be insulated. Did they insulate it internally or something? I assumed the still had them, but it just flew enough to be an issue.
However, despite all of that, I believe Buran/Energyia was very expensive like the Shuttle, not cheap because it was a reusable spacecraft, even if it was more simple and flexible. I think the one dirty little secret that the Sovietís didnít know from STS, was the huge costs of STS. We could afford those costs, but the Soviets broke their bank trying to get there. They stole the design, but didnít steal the cost information. And you could say, thatís how we got even. ;-)
A few other issues with Energyia/Buran.The Zenit boosters didnít have the O-ring problem, but thatís not to say they wouldnít have had other problems. The Zenit boosters have had their issues over the years. Out of 80 total launches, 10 failures and 3 parital failures? A failure on Buran could have resulted in a Challenger type incident, depending on the nature of the failure. The Shuttle SRBís turned out to have a pretty reliable flight rate comparatively. 1 failure in 271 launches I think.
Also, IMHO, the Soviets copied some drawbacks of the shuttle when they didnít have to with their changes. They could have designed Energyia to be inline, and mounted Buran on the top. ....Especially with their budgets and assets. Perhaps a smaller 30-40mt launch system, say a 5m hydrolox core with two RD-0120ís and two outboard Zenit booster would have launched a smaller shuttle, and then individual payloads for space station components or whatever. Buran or Shuttle could only put 20-25mt to LEO, so a 30-40mt system would better that. Then launch a mini-Buran to rendezvous with the payload, rather than carrying it up with it. Maybe that could have been sustainableÖ But they followed us into the budget issues that followed the large reusable spaceplane/cargo hauler in order to have ďparityĒ with us.
In terms of economics, the RD-0120 hydrolox engines on the Energia's core were simpler, single-turbopump designs with modestly inferior performance compared to those on the Shuttle. However, they cost a lot less because it the Soviets weren't pushing to the limits of engine tech with them and they weren't designed with lots of re-use in mind. It may very well have been cheaper for the Soviets to have produced them in large quantities rather than painstakingly refurbish them after each flight. Heck, that might have been cheaper for the shuttle as well.
Didn't the Soyuz have an auto-docking feature way back in the 1970s? If not, when was that added? Anyone know? I would think an auto-pilot could have been developed and added to the shuttle, given our electronics were much more advanced than the Sovets'. Regardless, I think the fact that the Buran had an auto-pilot was a major safety advantage over the Shuttle. If the Soviets had had a problem early in the program, it would not have cost cosmonaut lives. Also, had they lost an orbiter, they could have brought it back to flight without risking the lives of crew, which the shuttle couldn't do. As was the case with STS-1 and the first flights after Challenger and Columbia, the launches were all manned. That's a heck of a lot of risk that the Soviets could simply have avoided. I understand some look at Zenit failures and say, "of course the Energia/Buran system wasn't safer than STS/Shuttle". However given the Soviets wouldn't have had to take the same risks with their shuttles, I think this might be a closer-run thing than some estimate.
I thought the Soviets had done cost estimates on the shuttle and found it didn't make economic sense. Thus they figured it had to have a military purpose, which made them doubly determined to have their own.
from http://www.astronautix.com/lvs/energia.htmWell there you have it, Lobo. The engines being mounted on the core was a choice of Glushko's to cut the developmental difficulties. I can't say I disagree with it either. Had the USSR not collapsed, I don't doubt they could have produced a truer SSME equivalent, but it seems they didn't think it worth the effort.
Aren't NASA budgets a matter of public record? I had always heard the Soviets couldn't understand the economic justifications being made for the shuttle based on their own analysis, so they figured it must have a military purpose. You could say their paranoia was what pushed them into making their own shuttle.
Though it only flew twice, you would think a failure rate like that would have done in one of the first two Energia launches. They did after all have some eight RD-170 engines between them, and not one of them had issues or failed a la the RD-171 on the Zenit.
AFAIK, the Buran could launch with 30 mt of payload in the payload bay, not 24 mt like the Shuttle. I do agree launching an inline shuttle would have been safer, but would it have been easier to integrate? Given the Soviets liked to do horizontal integration (see any number of Energia pictures with Polyus or Buran), I would bet they found the engineering challenges not worth it. They could have done vertical integration, but I'd guess based on Spacex going with horizontal integration over vertical integration that this isn't a cheap way to do things.