Politicalnomad wrote:
What if the Soviets realize that their technological limitations mean that something like the N1 is literally just going to end up as a spectacular failure? Instead they opt for the EOR strategy, which theoretically makes the launchers a lot less complex to build, and much more in scope of competence. Instead of one giant launcher, the Soyuz 7K-LOK, the LK lander, and any other components they would need launch separately and dock in earth orbit before making a run at the moon.
But am I right or wrong to think that instead, they're merely going to end up with an entirely different set of problems which they may or may not be able to solve?
First of all I'll point out that EOR WAS in fact the plan from the start*. The N1 didn't have the energy to 'throw' a significant payload to the Moon without LH2 upper stages, (or something better than kerosene/LOX at any rate) so at least two launchers were required to assemble a Moon mission. It was not until the larger "Super-Boosters" like the UR700 with high performance hydrogen, (or nuclear) upper stages were proposed the Soviets began to have the on-orbit mass to do a 'single' launch architecture. The initial proposals were to use multiple R7's and Vostok vehicles, (later Soyuz) and multiple dockings to build up a Lunar Flight Complex. The 1964 proposal for a single launch, (two Cosmonaut) N1-LK3 assumed better efficiency than the N1 was actually capable of and it was found that either a Proton or second N1 would be required to launch the Lunar Transfer Stage which would dock with the crewed Soyuz and LK lander in Earth orbit before launching for the Moon.
There have been appearing of late 'revisions' which state (with no apparent certification or supporting documentation that I can find) that the Soviets had been working on and planning on equipping either or both of the N1 and Proton with hydrogen upper stages by the early and mid-60s to allow a 'single-launch' architecture but there's no evidence of this and in fact they lagged significantly behind in such development.
What was needed was practice and development of rendezvous and docking technique which lagged specifically because they main concept avoided that by going for the 'single launch' program. As it was the Americans were convinced early on that the "single-launch" and "direct landing" options would require such a huge booster (NOVA) that it was not feasible that both the booster and Apollo could be developed in time to meet the "less than a decade" goal. Von Braun and most of NASA had planned on EoR as the baseline mission plan with the only question being what form the Lunar Landing would take.
One very common misconception was that the "choices" were EITHER EOR, Direct Landing, or LOR when in fact LOR was always an option and was actually both compatible and supporting of EOR. The main 'issue' was that "Direct Landing" (where the whole lunar spacecraft lands on the Moon) was quickly found to be the 'simplest' option but the most complicated to carry out as well as the most mass intensive. On the other hand while EOR was found to be relatively 'cheaper', (no need to develop a large booster like the Saturn-V since the Saturn-1 had adequate payload) required extensive on-orbit assembly and operations which could not be completed in the time available. LOR replaced the need to launch, land and then re-launch the whole spacecraft to and from the Moon and therefore needed a smaller booster than NOVA such as the Saturn-V with a smaller, lighter single use Lunar Lander craft. Since the Saturn-V was already in development LOR came to be understood as the only meant to meet the time deadline despite the higher cost.
But since the initial concept required rendezvous and docking in Earth orbit the US set out to develop and prove those operations with the Gemini program. Along the way they also developed the techniques and technology for LOR as a 'side benefit'. On the Soviet side they had intended from the beginning to also develop rendezvous and docking and the Soyuz was designed with that in mind but between delays in development and technical and programmatic issues Soyuz was too late and neither Zond nor TKS were ready in time either.
Even by the Apollo-Soyuz Test Project (
https://en.wikipedia.org/wiki/Apollo–Soyuz_Test_Project) the Soviets were less proficient than the US in rendezvous and docking.
*Initially the plan was to use multiple R7 derived boosters to loft a crew vehicle, (originally an advanced Voskhod later the Soyuz) a lander/return stage and finally an orbital transfer stage which would all dock semi-automatically in Earth orbit. (A key point here is the Soviets preferred semi or fully automatic to human control whereas the US preferred human over automatic control for rendezvous and docking) Due to the payload of the R7 they'd need more than just the basics though. For example two launches to deliver the landing AND then the return stage. Two launches for the Earth and Lunar departure stages. (Keep in mind that at this point Direct Landing is the baseline concept) Finally they would then launch the crew and "top-off" propellant loads for the stages in orbit. Since the propellants were to be kerosene and LOX, (Korolev kept rejecting Glushko's offers of "high-performance" but toxic storable propellants and engines. And Glushko was unwilling to work on more powerful Kero-LOX engines let alone LH2 engines)
The "problem" with EOR, especially a large scale program that requires multiple rendezvous and docking events, is that any single launch failure can put the whole mission in jeopardy as by the time you can launch a replacement mission on-orbit propellant will have boiled off, electronics and other systems will have run longer than planned and overall systems will be closer to "Mean-Time-Between-Failure" limits so your chances of additional failure during the mission goes up greatly.
This of course assumes that all your EOR stages are simply floating around un-tended, and since everyone "knew" that we'd built a space station/construction base in orbit before we went to the Moon the stages would be monitored and maintained so who would be silly enough to simply loft stages into orbit without all that? And who'd go directly from the surface of the Earth to the surface of the Moon and back to the surface of the Earth anyway? That's going to take designing and building a single ship to do the three very different jobs! Much easier, (and cheaper) to build an efficient launcher that goes from Earth to orbit, (and back) then transfer to a ship that goes from Earth orbit to Lunar orbit where you meet an efficient Lunar surface to orbit ship and then ride that same system back to Earth. Don't you think?
Pipcard wrote:
When I asked some people at the NASAspaceflight.com forum, they told me the real problem was the lack of proper test-firing, not the number of engines.
Proper testing, (all up systems and engine testing which they had no capability of doing prior to actually launching) proper Quality Control, proper budget, even more time pressure than NASA, worse relations between 'contractors' for the various systems, parts and planning, the list goes on and on. Yes very much the number of engines in and of themselves wasn't even a 'clear' reason for the design to fail after all we'll see almost as many powering a heavy LV in the near future
(27 versus 30)
Part of the "problem" that WAS designed in however was the lack of payload to Earth orbit with all kerolox stages. (Similar issue is why neither the Falcon-9 or Falcon-9 heavy have significant interplanetary payloads) Both the Saturn-1 and V would have had similar issues with "only" kerolox stages to work with which is why Von Braun became a proponent of and then pitched LH2 so early.
Randy
