Author Topic: What would a better Saturn V/Lunar Program have looked like?  (Read 17918 times)

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437
 What would a better Saturn V/Lunar Program have looked like?

Yet another hypothetical, and intellectual exercise.

We’ve explored what a better STS would have looked like, and what if Apollo/Saturn had never been cancelled.  However, the problems with Saturn that lead to the hope of a cheap/reusable STS (which didn’t exactly pan out, obviously), were because of the huge costs of the Saturn V system.

As I understand, a monolithic in-line system like the Saturn V was the most simple, most reliable heavy lifter if you are starting from a clean sheet design like NASA was in the 60’s.  If they were to go to the moon, they needed a new rocket.  And Monolithic inline has the fewest elements doing the least amount of staging.  Fewer, but large, engines mean the most reliable/simple MPS’s on the stages.  Each stage only has one LOX tank and one fuel tank, so it’s the most mass and volume efficient design.
I think this was a lot of the reason this system was chosen for Saturn V, and why the RAC-2 studies looked so tempting for SLS.

However, it has some drawbacks.  None of the elements would be shared by any other launcher, so NASA bore all the development and overhead expenses 100%.  It’s good at launching heavy loads, but not so good at scaling back to intermediate loads.  INT-20 and INT-21 made for some interesting concepts, but they still weren’t great ways to scale down.  INT-21 actually was pretty good for a fairly heavy LEO launcher.  INT-20 had a much too powerful first stage for it’s S-IVB upper stage.  Saturn II concepts needed either new S-II engines, or SRB’s to just get off the ground. 

So there’s 3 whole stages, and two different engine lines that would be used for nothing else that NASA would need to maintain.  When the Apollo money was rolling in, they were flush with cash and money was no object.  So for this exercise, let’s assume that some bright bulbs in NASA decided to conceive a system that would be sustainable in the long run after the Space Race was won, and they understood that level of funding wouldn’t be around after that.  So instead of the mightly monolithic inline Saturn V, something else was conceived that would have still got us to the moon before January of 1970.  Maybe that would be utilization of existing assets in the Titan-III of that time to have the least development and most cost sharing with USAF, or maybe it would be new engines and rockets, but in parallel staged configurations that would have been cheaper to maintain, and had a higher production rate, and NASA could have afforded after the Space Race was won.  So perhaps some of the concepts talked about in the “What if Saturn have never been cancelled” thread, like multiple 6.6m kerolox cores strapped together?
Or maybe it would be a combination of both.  A smaller kerolox or hydrolox first stage with multiple Titan III SRB’s strapped to it, and an S-IV type upper stage/EDS?
But keep it all in the technology and knowledge of the time.  Space travel was brand new, and Gemini was the testbed for technologies that were co-currently being developed for Apollo as Apollo and Saturn and the LEM took shape.  We didn’t’ even know if we could do an EOR or docking in space until we did it during Gemini.  We know today we could do complex in orbit assembly, and probably could mount a lunar program all based on small EELV/Titan-III class launchers, and propellant transfer.  But that would have been a real unknown back then.  So any system alternative could probably have some of that, but not too much. 
And whatever it is, would also need to be useful in the pre-Apollo 8 test flights like the Saturn 1B was, and useful in the post-Apollo 17 back-to-LEO NASA Era that would have been potentially affordable enough that STS wouldn’t have had to be conceived.  Maybe even Apollo 18, 19, and 20 could have flown under the budget cutbacks with the budget savings?

So in short, how could we have gotten to the Moon by December of 1969 in a cheaper and more sustainable way, that could have then carried on past Apollo 17, eliminating any HSF gap, and then dovetailing into a 70’s and 80’s new focus for NASA which was basically LEO space stations?  (although STS was so expensive, that basically got put on hold for two decades outside of Skylab)

Myself, I’m thinking about a 6.6m-ish hydrolox first stage, that would be basically a stretched version of the S-IV, with an S-IV on top.  Both powered by J2’s.  Then multiple Titan-III SRB’s around it sufficient to get around 120mt to LEO.  The core stage could even be lit after takeoff like Titan’s core was, as the J2’s had to be developed to air-start to be an EDS.  A cluster of 3-5 on the first stage (whatever’s required depending on fuel load and when they’d ignite), and one on the upper stage.  RL-10’s could be used on the S-IV-like upper stage as well, as they already existed and could have been used without the need for a 2nd engine development program. 

So, one production line turning out two length cores of the same diameter.  One new hydrolox engine development program.  Use of existing Titan IIIC SRB’s (available by 1965), so no new development there.  Titan SRB’s were used all through the 60’s, 70’s, 80’s and 90’s so they’d have been available for a lot of NASA history, and NASA could have updated their core when USAF upgraded SRB’s along the way.  The LV is scalable by the number of SRB’s attached to it, so it could do more medium lift configurations, as well as heavier lift ones. 
If you couldn’t fit enough SRB’s on it to get a Saturn V class payload to LEO for a single launch Apollo lunar architecture, then a two launch architecture with EOR and then Apollo LOR could be done.  Lauch of the LEM and EDS from Pad 39A, and Launch of Apollo CSM from Pad 39B, within perhaps hours or a day of each other.  EOR, Apollo docks in the same position on the LEM in the cradle on the S-IV that it was for Apollo TLI, and then the TLI burn is done. 
If two launches are required, then that does add an extra element to the mission.  But the mission already depended on LOR.  At least a failed EOR wouldn’t result in LOC like a failed LOR would have….two of the crew anyway.  So I don’t think that would have been a major problem by 1969, and KSC has two pads and could accommodate two launches in a short time frame.  The VAB certainly could have processed two LV’s at once, so not real problem there. 

After Apollo 17, Skylab still could have been built from an S-IV hull.  A Skylab two could have used two or three similar modules attached to a central hub.  It might need to be launched on top of the S-IV upper stage to get it into LEO.  But again, shouldn’t be a problem.  Apollo CSM could have been continued and refined for space station taxi service.

Although it’s not as sexy as the Shuttle, the Russians have been flying Soyuz and Proton in one form or another since the lat 1960’s, and they’ve never had a HSF gap like we have.  So there’s something to be said for simple, cheap, easy, and reliable. 

But there might be better ideas out there.  What do you guys think?

Offline RanulfC

  • Senior Member
  • *****
  • Posts: 4595
  • Heus tu Omnis! Vigilate Hoc!
  • Liked: 900
  • Likes Given: 32
Good one... Again :)

Given the "restrictions" I'll have to think about it a bit before digging in but I think I'll take a "swing" at part of the post:
Quote from: Lobo
Although it’s not as sexy as the Shuttle, the Russians have been flying Soyuz and Proton in one form or another since the lat 1960’s, and they’ve never had a HSF gap like we have.  So there’s something to be said for simple, cheap, easy, and reliable.
... And they haven't ever gone to the Moon either so that's something to consider. They also "saw" the need for a massive, and expensive HLV for about the same "reason" the US did.

Despite being "simple, cheap, easy, and reliable" and while they built several Earth-Orbit Space Stations over the decades, up to Mir they still hadn't "quite" found it "sustainable" enough over the long run to utilize the system to develop and deploy anything for manned flight beyond LEO.

While it is true the Russians never had the HSF "gaps" the US did, neither for the most part did they seem to take HSF or "space" seriously to the extent that the US did at the time.

It's always actually "amazed" me that the Russians have NOT gone to the Moon given the way they built a "workable" system around Soyuz-Proton. During the "gap" between Apollo and Shuttle I could have seen them putting their steady and increasing space experiance to work to push a modular mission to the Moon having their crew(s) stay longer than ours to prove the "point" :)
(After all the rhetoric was that they would always out "last" a capitalist system :o)

But they couldn't. Various factors, (lack or political, financial support, etc...) combined to keep them from starting "another" space-race and that "battlefield" was set aside until much, much later. And even today though Russians continue to fly into space they've scaled back their operations greatly and in a great part it's because their system may be "simple, easy, and reliable" but I don't think its really all that "cheap" and it still requires a huge amount of infrastructure and people to keep running. Worse yet it actually had a few "advantages" over the NASA/Apollo program in that part of it was paid for by the military for their use and though it was quickly made "obsolete" for military use and devoted to just launching payloads it STILL isn't "cheap" enough or "mass-produced" enough to really gain any advantages.

I'm "guessing" that says something about the long term viability of the system and "way" that payloads in general and HSF in particular is "done" that needs some fundamental re-examination... But that's ANOTHER topic :)

Looking at what we "know" now versus what people "knew" then I think we're going to be hard pressed to NOT come out to the exact same conclusions under the cited circumstances without a serious amount of hand-waving to get the "results" we want :)

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline Proponent

  • Senior Member
  • *****
  • Posts: 7277
  • Liked: 2782
  • Likes Given: 1462
Of course, we now know that while the Soviets were actively conducting the Salyut/Mir program, they were also developing Buran and Energia.  That must have cost a lot money and would have made it difficult to pursue a manned lunar program.  Maybe if they hadn't decided to spend so much money on the big rocket, the might have been able to use their smaller rockets to go to the moon (this sounds depressingly familiar...).
« Last Edit: 10/15/2012 09:14 pm by Proponent »

Offline IRobot

  • Full Member
  • ****
  • Posts: 1312
  • Portugal & Germany
  • Liked: 310
  • Likes Given: 272
I would just upgrade the RP1-LOX engines for better ISP and either reduce the overall size, maintaining LEO payload or maintaining the size and increasing the payload.

In terms of purpose, I think the best would be to build the ISS with some Skylab size elements. Four-five launches would be enough.

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437
Of course, we now know that while the Soviets were actively conducting the Salyut/Mir program, they were also developing Buran and Energia.  That must have cost a lot money and would have made it difficult to pursue a manned lunar program.  Maybe if they hadn't decided to spend so much money on the big rocket, the might have been able to use their smaller rockets to go to the moon (this sounds depressingly familiar...).

Yea, it’s hard to really compare exactly our program and the Russians.  We had a lot more actual money to spend, and a greater array of expertise, brain power, and advanced technology than the Soviets did.  Some of that was their economy, some of it was their closed society that (IMO) would have made it tougher for some of their best and brightest to work their way into a position where they could have contributed to the Soviet effort.  So I think they were working from a more limited pool than we were, with more limited resources.  As I understand, they couldn’t build large cylindrical cryo tanks, so their big tanks for N-1 had to be spherical, which was limiting in geometry.  And they didn’t have really much knowledge in hydrolox propulsion, so they tried to do everything in kerolox, which made their upper stages far less performing. 
I think they had a pretty huge investment in N-1, and then couldn’t get it flying so all of that time and resources were sort of wasted.  And then again later with Energia/Buran.  They just didn’t have the resources to sustain such an expensive system along with their normal expendable launches.  Even more so as the Soviet Union started to crumble in the late 80’s.   There was nothing wrong with Energia, but it sort of ended up being another big, expensive heavy lifter that never really did anything.  Those two programs, and the timing of them, might have been what kept the Soviets from trying to get to the moon later.  If they hadn’t been trying to get Energia to launch a Soviet Shuttle for military parody (the main goal of Buran I think), and focused on using Energia to be an inline heavy lifter launching a lunar capable soyuz and updated LK lander, maybe they could have gotten there in the 80’s?  Energia with an EDS could have certainly performed the mission, and the hydrolox core showed by the 80’s the Soviets could do hydrolox, something they couldn’t do in the 60’s. 

Dunno, probably lots of reasons.  Heck, we might not have gotten there if the Soviets actually had beaten us.  Political support could have dried up for it.  Although maybe NASA would have then been focused to going to Mars or something, to get a different “first” for America.  Who knows?

Offline Lars_J

  • Senior Member
  • *****
  • Posts: 6160
  • California
  • Liked: 677
  • Likes Given: 195
It seems like the best way to build a Saturn V like LV on the cheap would be to have a heavy and intermediate launch vehicle using the same components. In this case the 1st stage and heavy boosters would be a 6.6m diameter RP core powered by two F-1. The second stage would be the S-IVB stage as is.

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437
Good one... Again :)

... And they haven't ever gone to the Moon either so that's something to consider. They also "saw" the need for a massive, and expensive HLV for about the same "reason" the US did.

Despite being "simple, cheap, easy, and reliable" and while they built several Earth-Orbit Space Stations over the decades, up to Mir they still hadn't "quite" found it "sustainable" enough over the long run to utilize the system to develop and deploy anything for manned flight beyond LEO.

While it is true the Russians never had the HSF "gaps" the US did, neither for the most part did they seem to take HSF or "space" seriously to the extent that the US did at the time.


I didn’t mean to imply the Russians did everything better.  They had achievements, and so did we.  We accomplished more technological achievements like a super heavy lift vehicle, landing on the moon, and building a big reusable space plane.  They got a man into space first (barely), but into orbit too, which we didn’t do until John Glenn.  They did a space station before we did.  They did in-orbit assembly of a space station before we did.  And they maintained HSF capabilities pretty much unbroken since the mid 60’s. 
Just saying there can be things to learn from them too.


It's always actually "amazed" me that the Russians have NOT gone to the Moon given the way they built a "workable" system around Soyuz-Proton. During the "gap" between Apollo and Shuttle I could have seen them putting their steady and increasing space experiance to work to push a modular mission to the Moon having their crew(s) stay longer than ours to prove the "point" :)
(After all the rhetoric was that they would always out "last" a capitalist system :o)

But they couldn't. Various factors, (lack or political, financial support, etc...) combined to keep them from starting "another" space-race and that "battlefield" was set aside until much, much later. And even today though Russians continue to fly into space they've scaled back their operations greatly and in a great part it's because their system may be "simple, easy, and reliable" but I don't think its really all that "cheap" and it still requires a huge amount of infrastructure and people to keep running. Worse yet it actually had a few "advantages" over the NASA/Apollo program in that part of it was paid for by the military for their use and though it was quickly made "obsolete" for military use and devoted to just launching payloads it STILL isn't "cheap" enough or "mass-produced" enough to really gain any advantages.


I’m not for sure, but I think after they couldn’t get the N-1 flying and lost the race to the Moon with us, they shifted focus to their LEO space station program.  Rather than arriving late to the Moon, with an inferior lander and capability to us.  I’d imagine there’s some politics in that, and they new even if N-1 got flying, it couldn’t put two crew and a lander the size of the LEM on the surface. 


Looking at what we "know" now versus what people "knew" then I think we're going to be hard pressed to NOT come out to the exact same conclusions under the cited circumstances without a serious amount of hand-waving to get the "results" we want :)


Well, obviously any of these hypothetical questions sort of assume that someone back then would have had the foresight/intuition, to have seen some of the problems we now realized in hindsight. 
As probably the SLS RAC-2 team found out, a big, monolithic in-line rocket is one of the fastest and most reliable and efficient ways to get a payload of a certain size into space for all the reasons I stated in my genesis post.  Especially when starting from scratch as Apollo was and as the RAC-2 team was assuming in their studies. 
But a big monolithic in-line can not be as “practical” a way to do it from the standpoints of launching anything other than your super heavy payload and cost sharing of systems and components, as some other systems.

So back in the early 60’s, a fledgling NASA who’d been beaten by the Soviets into space, had a mandate from a popular president, cold war politics, basically a blank check for funding, and very little knowledge of the challenges and complexities they would face.  A monolithic in-line is very simple, and making it large enough to do the entire mission in one launch reduces mission complexity.  I’m sure it seemed like the most logical choice.

But what if someone had the intuition to fear a budget axe falling after they achieved their goal, and the political forces weren’t backing them any more?  And he didn’t want to be stuck with this giant, expensive rocket that really wasn’t affordable without that big budget and a mission of doing lunar landings?  And wanted something that could get us to the moon by 1969, but also would be affordable after that too?
That’s kind of the the hypothetical here.  So yea, this thread needs to take some creative liberties to set up a scenario that someone might have thought beyond the most direct way to get from point A to point B….something that could also get to point C afterwards.  ;-)

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437
It seems like the best way to build a Saturn V like LV on the cheap would be to have a heavy and intermediate launch vehicle using the same components. In this case the 1st stage and heavy boosters would be a 6.6m diameter RP core powered by two F-1. The second stage would be the S-IVB stage as is.

Yea, I had this thought too.  Build that 6.6m mono-core kerolox booster, using either F-1 or H-1 engines.  And strap 3 or 5 of them together for a heavy lift first stage.

However, if you are going to the moon, then you need an EDS.  A multi-core first stage using a gas generator (low ISP) engine would be limited once it got past the lower ascent, wouldn’t it?  Could an S-IVB stage make up the difference, and then also to the TLI burn?  In Saturn, the S-II did most of that upper ascent.  The S-IVB didn’t have to do a whole lot in addition.  Wouldn’t a multi-core first stage kerolox GG only be useful to about the altitude the S-IC was?  And if you need two more stages on top like the S-IC did, then what have you gained?  Other than a bit more scalable system.

That’s why I thought of the two hydrolox stages both based off the S-IV stage.  So hopefully it’s not quite like developing two new stages completely from scratch the way the 3 Saturn V stages were developed from scratch.  Hopefully development of these two 6.6m hydrolox stages would be more like developing “1.5” new stages.  ;-)

And then for the “first” stage, the existing Titan IIIC SRB’s would be used, so no development needed, and no need to support that production by NASA alone. 
I’d picture the stretched hydrolox core to look a bit like the Delta II first stage with it’s ring of SRB’s around it, in it’s heaviest lift configuration.  It would have less SRB’s, and the core would do more of the initial ascent for the medium lift configurations.

Offline ARD

  • Member
  • Posts: 71
  • Liked: 0
  • Likes Given: 0
Way I see it, a kerolox core, 6.6 meters across with a set of uprated H-1 engines, and a hydrolox stage (J-2) on top, is the way to go.  Lash 3, 4, or 5 of those together and you get the capability of a Saturn V (or at least an INT-20) with little hardware that you wouldn't have for purely LEO or space station resupply missions.  The H-1 engines can see some use on smaller LVs--apparently, those were used on Deltas in the 1970s.  You have this way only two engine production lines, one of those also supplying engines for DoD and smaller unmanned missions. 

Basically, my suggestion is Falcon Heavy (or Atlas Phase II), but with a somewhat stretched Saturn IB as the starting point. 

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437
Way I see it, a kerolox core, 6.6 meters across with a set of uprated H-1 engines, and a hydrolox stage (J-2) on top, is the way to go.  Lash 3, 4, or 5 of those together and you get the capability of a Saturn V (or at least an INT-20) with little hardware that you wouldn't have for purely LEO or space station resupply missions.  The H-1 engines can see some use on smaller LVs--apparently, those were used on Deltas in the 1970s.  You have this way only two engine production lines, one of those also supplying engines for DoD and smaller unmanned missions. 

Basically, my suggestion is Falcon Heavy (or Atlas Phase II), but with a somewhat stretched Saturn IB as the starting point. 

See my previous post.  I think what you describe would be a good LEO heavy lifter, but the idea of this thread is to go to the Moon.  How much of the ascent can the low ISP (gas generator) cluster of 6.6m kerolox cores do?  The S-IC was this, just in a wide-body version.  It burnt for 150 seconds.  But the entire burn to LEO was 675 seconds (over 11 minutes) when you add the S-IC, S-II and S-IVB first burn up. 

The Falcon 9’s gas-generator first stage burns for 170 seconds.

So how long of a burn do you think this cluster of 6.6 kerolox gas-generator engine cores you’ll get?  I’m no rocket scientist, but I think probably much beyond the burn time for the S-IC or F9, your performance starts dropping off considerably.  Staged combustion kerolox will get a longer useful 1st stage burn, but I don’t think we had any at that time.  Just the Soviets. 
And even then, the Atlas V’s staged combustion engine burns for 253 seconds, still requiring a considerable burn from Centaur to just get to LEO.  The S-IVB stage only needed to do 165 second burn to get to orbit. 

(although perhaps with cross feed, such an LV could get a longer burn out of the first stage...but cross feed would add complexity to this new LV in the 1960's...)
I’m just thinking if you are trying to get to the Moon, an upper stage on a gas-generator kerolox engine that could do both the 2nd stage ascent as well as the TLI burn would be very large.  It would be something like the S-II and S-IV stage combined in one for a Saturn V class LV.    I think that’d be some big mass penalties for the TLI burn.
That’s why I’m not so sure that’d be the best way to go. 
So my concept is to have a sustainer hydrolox stage, either ground lit, or air lit. (a J2 could do either).  Let the solids do the initial heavy lifting and the core burn almost to orbit.  Then the S-IV stage can do the last part of the ascent, and the TLI burn as it did for the Saturn V. 
Then the H-1 and then F-1 are never developed.  The H-1 was later used for Delta in the 70’s, but (according to Wikipedia anyway), the H-1 was developed specifically for Saturn 1.  The F-1 was developed for Saturn V.  My concept eliminates both of those development programs.  RL-10 already exists, as does Titan SRB’s.  NASA need only develop J2 for this concept.  “1.5” new stages and 1 new engine.  I think that’d beat Saturn’s 3 new engines and 4 new stages (between Saturn 1 and Saturn V) anyway.

Perhaps some people with more knowledge on this could weigh in?

Offline Lars_J

  • Senior Member
  • *****
  • Posts: 6160
  • California
  • Liked: 677
  • Likes Given: 195
It seems like the best way to build a Saturn V like LV on the cheap would be to have a heavy and intermediate launch vehicle using the same components. In this case the 1st stage and heavy boosters would be a 6.6m diameter RP core powered by two F-1. The second stage would be the S-IVB stage as is.

Yea, I had this thought too.  Build that 6.6m mono-core kerolox booster, using either F-1 or H-1 engines.  And strap 3 or 5 of them together for a heavy lift first stage.

However, if you are going to the moon, then you need an EDS.  A multi-core first stage using a gas generator (low ISP) engine would be limited once it got past the lower ascent, wouldn’t it?  Could an S-IVB stage make up the difference, and then also to the TLI burn?  In Saturn, the S-II did most of that upper ascent.  The S-IVB didn’t have to do a whole lot in addition.  Wouldn’t a multi-core first stage kerolox GG only be useful to about the altitude the S-IC was?  And if you need two more stages on top like the S-IC did, then what have you gained?  Other than a bit more scalable system.

Well clearly if you are looking for a more affordable system with fewer components, then you might not get Saturn V performance, and so your lunar landing strategy might not favor LOR.

As for a TLI burn - my suggestion would be to put a shortened S-IVB as a 3rd/TLI stage for lunar missions. Same tooling and engine as S-IVB.

So with two engines (F-1 and J-2), and one tank tooling (6.6m), you could lift anything from 25t with a single stick, to 85t for heavy variants (or perhaps significantly more). Costs could be brought down by mass-production of the above elements. (BTW my performance numbers are just guesstimates, feel free to correct)
« Last Edit: 10/16/2012 03:08 am by Lars_J »

Offline RanulfC

  • Senior Member
  • *****
  • Posts: 4595
  • Heus tu Omnis! Vigilate Hoc!
  • Liked: 900
  • Likes Given: 32
Don't forget that the biggest "hold-up" on the whole Apollo program was the decision on the "how" and it came down in the end to "making" the deadline or not. EOR was the 'prefered' method for all the "space" advocates inside and outside NASA, but the overall "timeline" meant it wasn't going to be done in less than a decade. After that it was either direct or LOR and direct simply needed TOO big a rocket to do.

Given "some" flexability and less "pressure" I'm pretty sure that some sort of EOR operation would have won out in the end. If there had been serious development issues with the Saturn-V and an up-rated and more "modular" Saturn-1 had been needed and developed you probably have a really good start on a flexible space transport system. However, (again) its a "NASA only" booster so there would be a cost to figure in. (Anybody come up with a GOOD reason for a manned military presence in space? The DoD/AF have been trying for years but no joy... Now if they could somehow "convince" the "powers-that-be" and THEY needed a Saturn-1 class booster you've got some good traction started... :) )

Reusabilty would always be in the "back" of everyones mind so you'd see work begun on trying to recover the Saturn-1 booster and later probably some sort of recoverable and reusuable upper-stage and/or vehicle. But if the flight rates never allowed the cost savings to appear overall the program cost might not be so bad.

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437

Well clearly if you are looking for a more affordable system with fewer components, then you might not get Saturn V performance, and so your lunar landing strategy might not favor LOR.

As for a TLI burn - my suggestion would be to put a shortened S-IVB as a 3rd/TLI stage for lunar missions. Same tooling and engine as S-IVB.

So with two engines (F-1 and J-2), and one tank tooling (6.6m), you could lift anything from 25t with a single stick, to 85t for heavy variants (or perhaps significantly more). Costs could be brought down by mass-production of the above elements. (BTW my performance numbers are just guesstimates, feel free to correct)

While this would be more scalable than the Saturn V, it’s still basically 3 stages, even though the 6.6m upper stage and S-IV stage could share the same production line, as in my concept.  So we’ll call it “2.5” new stages.  And two new engines.  Not sure if it gains much (or any) development savings over Saturn V (if we exclude Saturn 1B)?

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437
Ok, so looking at my concept a bit more, a few assumptions.

1)   EDS with roughly the same performance as the S-IVB stage.
2)   Hydrolox core stage with roughly the same capacity and performance of the S-II stage.
3)   8 Titan IIIC SRB’s can roughly approximate the performance of the S-IC stage.

#2 might mean the core needs to be a little wider than 6.6m.  Perhaps 7-8m.  The EDS would then be wider and shorter than the S-IV stage, as the idea is they share the same production line. 

So, for a 1-launch architecture:

The Titan UA1205 SRB available in 1965 had about 1.3M lb thrust, and 115 seconds of burn time.  Six of them is about equal in thrust to the S-IC stage, but these SRB’s are heavier, lower ISP and don’t burn for quite as long. (S-IC burned for 150 seconds).  We’ll assume 8 UA1205 SRB’s to make up that difference.  Geometrically, they should fit around the core ok.  The core might even need to hold a little more hydrolox than the S-II to make up the burn length difference, but that’s really not a problem.  The core will be designed from scratch (just as the S-II and S-IC were) and can be whatever it needs to be. 
So, if the core has  a cluster of 5 J2 engines, and they air start after SRB separation, just as they did after S-IC separation, then the core basically performs the S-II burn.  And the EDS performs the S-IVB burns with a single J2.
Since we are following the performance of the Saturn V, and we know what it could do, it can be roughly extrapolated to say this could then lift roughly the same payload to LEO and TLI as Saturn V.

Some issues…
Would 8 SRB’s burning cause any problem to the non-burning cluster of five J2’s?  Could the SRB nozzles be lowered  below the core engines a bit to compensate if so?
And because the SRB’s can’t throttle down, would there be too many g’s pulled with that many SRB’s burning?
Maybe my assumptions about 8 SRB’s approximating the S-IC is incorrect.

If those issues proved to problematic, a two launch solution could be done.

Using this data as a reference:

http://www.friends-partners.org/partners/mwade/lvfam/saturnii.htm

It looks like my concept with four UA1205 SRB’s could get almost 52mt to LEO, assuming the core is roughly the performance and capacity of the S-II.  That’s a bit lean for the latter Apollo missions, so perhaps a 6 SRB launch to launch the LEM and the fueled EDS, and then Maybe another launch without the EDS, letting the core put the Apollo CSM into orbit for EOR with the LEM/EDS.  Looks like some of the Saturn II configurations with Titan SRB’s didn’t even need the S-IVB stage to put payloads in LEO.  IT just needs to get about 30mt to LEO for the fully fueled Apollo CSM.  It lists a variant with just the S-II stage and four SRB’s getting 39mt to LEO, so it looks like that’d work with a core-only stage for Apollo.

Both stacks are rolled out to Pads 39A and 39B.  The EDS/LEM is launched first into a parking orbit and checked out.  If everything is ok, then the crew is launched from the other pad for EOR.  Once Apollo CSM docks on the LEM’s docking port, the EDS does the TLI burn, and everything else is just like how all the Apollo missions actually went down. 

I think that would work out ok.  It’s only adding in one element over Saturn V, which is the EOR. 

Again, the advantages is a pretty scalable system, only one engine to develop, and “1.5” stages to develop.  It can put up pretty sizable LEO payloads in a single launch, such as large space station modules, post-Apollo.  However, just the core along with probably 2 SRB’s should get S-1B sized payloads into LEO for Space Station Taxi.  So that would’t be a very expensive LV to launch and maintain.  The EDS could actually be shelved during the post Apollo era, if it wasn’t needed, but since the same production line that makes it is still making the hydrolox core, it could be made again any time it was required for a mission. 

This LV would always need at least two Titan SRB’s to launch, as it can’t get itself off the ground otherwise, obviously.   Like the Saturn II. 

So I guess, in short, this concept is the Saturn II concept, just with the EDS and core sharing a production line, and the core being design from the jump to mount combinations of Titan SRB’s, where the S-II in the Saturn II concept wasn’t and would have had to be redesigned.  This saves the development of the H-1, the F-1, the S-1B and the S-IC.  One engine and two stages. To develop.  And one engine and one stage production line to maintain.

I am probably overlooking something pretty important with this concept, but what?  Otherwise, it seems pretty practical. 

Offline Proponent

  • Senior Member
  • *****
  • Posts: 7277
  • Liked: 2782
  • Likes Given: 1462
As background to the topic at hand, allow me to point out the Army's 1960 study "A Lunar Exploration Program Based upon Saturn-boosted Systems."  As far as I know it's the most detailed look in the early-1960s at lunar missions involving more than two launches.  A number of scenarios are discussed, but the preferred one, diagrammed on PDF p. 262, involves six launches of an 80,000-lb-class launch vehicle (equivalent to the Saturn C-3, though that's not quite the configuration shown in this study): five tanker launches plus one for the spacecraft.  The spacecraft landed directly on the moon, carried two astronauts, and was hydrogen-fuelled.  Make what you want of the weight estimates.  On the one hand, the a weight savings could have been made by using LOR rather than a direct landing.  On the other hand, 1) early 60s weight estimates were often on the optimistic side (John Houbolt thought one C-3 would suffice for LOR with a crew of three!), 2) replacing lox/hydrogen with hypergols increases weight, and 3) so does increasing the crew from two to three.

The study also claims that if the workhorse launch vehicle had a capacity of less than 45,000 lb to LEO, then not just re-fuelling but also assembly would be required in LEO.  Forty-five thousand pounds was about the capacity of the proposed Saturn C-2, but in this study it was the Saturn B-1 (with a lox/RP-1 second stage) that was under consideration.

There's another study, done shortly after NASA was assigned the moon mission, that compares several approaches, including, IIRC, orbital assembly or re-fuelling based on Saturn C-3s, EOR, LOR and direct, that's quite interesting.  Unfortunately, I don't have access to it at the moment.

Offline Proponent

  • Senior Member
  • *****
  • Posts: 7277
  • Liked: 2782
  • Likes Given: 1462
Now if they [USAF] could somehow "convince" the "powers-that-be" and THEY needed a Saturn-1 class booster you've got some good traction started..

The Air Force did convince the powers that be that it needed the Titan III-C, which was in the same class as the Saturn I (though somewhat smaller than the Saturn IB, or course).  I think there could have been an opportunity there to have a Saturn I-class booster used by both the Air Force and NASA.  As it was, there were some fierce arguments between the Titan III-C and Saturn camps.  There's an interesting Titan III history that's been posted somewhere on this site (by Blackstar?).  The Air Force was claiming at one point, for example, that the Saturn's 8-engine cluster was so complex that it wasn't clear it would ever work, let alone be reliable.
« Last Edit: 10/17/2012 02:21 pm by Proponent »

Offline Lobo

  • Senior Member
  • *****
  • Posts: 6915
  • Spokane, WA
  • Liked: 672
  • Likes Given: 437
Now if they [USAF] could somehow "convince" the "powers-that-be" and THEY needed a Saturn-1 class booster you've got some good traction started..

The Air Force did convince the powers that be that it needed the Titan III-C, which was in the same class as the Saturn I (though somewhat smaller than the Saturn IB, or course).  I think there could have been an opportunity there to have a Saturn I-class booster used by both the Air Force and NASA.  As it was, there were some fierce arguments between the Titan III-C and Saturn camps.  There's an interesting Titan III history that's been posted somewhere on this site (by Blackstar?).  The Air Force was claiming at one point, for example, that the Saturn's 8-engine cluster was so complex that it wasn't clear it would ever work, let alone be reliable.

Yea, I think a bit of a problem there, is the USAF wanted a system based on their Titan ICBM, which needed storable propellants, as it would be sitting around in missile silos for years.  So hypergolics or solids were the obvious choices there.
NASA doesn’t need rockets that use storable propellants, they can fuel it up prior to liftoff just fine.  So I could see NASA wanting to go with higher performance non-storable cyrogenics like kerolox and hydrolox.  Titan’s hypergolic core was obviously not a really efficient propellant, and very toxic. 
USAF could certainly use a cryogenic rocket like NASA for their satellite missions, because the criteria is the same as for NASA.  But (I am assuming here), since they already had the Titan II ICBM, by adding some SRB’s to it, they could get the payload capacity they needed, without the need for another separate rocket system to maintain.  And that makes sense really. 
The problem for NASA is that it would be pretty difficult to do a lunar mission with just Titan IIIC launches.  It would require a bunch of in orbit assembly and elements that had never been done, and weren’t sure could be done in space until Gemini showed they could.  But even then, I’m sure they wanted to keep the number of in orbit assembly and docking maneuvers down to a bare minimum to reduce the LOM or LOC chances for a lunar mission, which would already be full of LOM or LOC risks.

It just would have been nice if the two could have come together on some things.  Like a smaller MLV which used USAF’s existing SRB’s.  USAF gets it’s Titan III, and NASA gets a crogenic high performance rocket that could do a lunar mission in two or perhaps even one launch.

Offline RocketmanUS

  • Senior Member
  • *****
  • Posts: 2226
  • USA
  • Liked: 71
  • Likes Given: 31
No better but different.
Titan IIIC and or Saturn 1B.
Space station launch by either with add on modules.
Assemble cargo or crew Lunar vehicle at station.

Station for space research or space assemble during the year for what space program was needed at the time. A lot smaller than ISS, but modules about the same size. Use modifies Apollo CSM for a short duration module, use for experimenting on new equipment and or things that they wanted to return to Earth after they were done with it at the station.

This could have given them the flexibility to do Lunar missions when they wanted to without a bigger commitment. Use hypergolic fueled EDS, easy to store in space till needed. Crew could have launched to station weeks before their intended launch window, no launch or weather delays this way. With these launchers Apollo CM would have had to add propellent to it's tanks at the station for a Lunar mission.

As far as a better Saturn V/Lunar Program have looked like, I think Saturn V would have needed to be replace by INT-20/21 and use a dedicated assemble station for BLEO missions and launch the LH2/LOX EDS last with crew already at the station for crewed missions.

We could have had the Apollo CSM in place for either time of mission even if they made a LEO version of the Apollo CSM, people and factory would still be there.

Offline go4mars

  • Senior Member
  • *****
  • Posts: 3748
  • Earth
  • Liked: 158
  • Likes Given: 3463
Sea Dragon. -Bob Truax
Elasmotherium; hurlyburly Doggerlandic Jentilak steeds insouciantly gallop in viridescent taiga, eluding deluginal Burckle's abyssal excavation.

Offline Lars_J

  • Senior Member
  • *****
  • Posts: 6160
  • California
  • Liked: 677
  • Likes Given: 195
However, if you are going to the moon, then you need an EDS.  A multi-core first stage using a gas generator (low ISP) engine would be limited once it got past the lower ascent, wouldn’t it?  Could an S-IVB stage make up the difference, and then also to the TLI burn?  In Saturn, the S-II did most of that upper ascent.  The S-IVB didn’t have to do a whole lot in addition.  Wouldn’t a multi-core first stage kerolox GG only be useful to about the altitude the S-IC was?  And if you need two more stages on top like the S-IC did, then what have you gained?  Other than a bit more scalable system.

That’s why I thought of the two hydrolox stages both based off the S-IV stage.  ...

While hydrolox makes a lot of sense for an EDS, I'm not sure I understand your "hydrolox focus". Sure, it matches NASA who at the time (and since then) has had a "hydrolox or bust" mentality. BUT... If you are really interested in a more affordable Apollo/Saturn-style program, it would probably be a good idea to take a second look at "kerolox". It still works over 100km altitude you know. ;) Hydrolox is great, but you have to balance the added performance with the added cost & complexity.

I'm not against hydrolox, but it there was one element I would not want to lose in a "better lunar program", it would be the F-1 engine.

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
0