What if Apollo/Saturn Had never been Cancelled?

[RyanC]

There were also proposals to develop a 6-man CM interior for logistics duties; which would have actually enabled a large crew to be supported on such a notational station; allowing for the station to actually be maintained/expanded and serious research done at the same time; something which can't be done with ISS at the present, due to Soyuz crew size limitations.

EDIT: fixed Logistics CM crew size.

[Kaputnik]

Why would a replacement SIB stage need to use two F-1s? Why not just use one F-1A?

[RyanC]

Why would a replacement SIB stage need to use two F-1s? Why not just use one F-1A?

A single F-1A would have 1.7 to 1.8 mlbf of thrust -- Saturn IB's S-IB had 1.6~ mlbf of thrust.

While going to a S-IC style tank architecture instead of clustering would save a lot of booster weight, you'd still have to unload mass from the Apollo CSM to put it into LEO. Well, that and you would not have a performance margin in case of an underperforming engine or one that cuts out early.

Also, having 86,000 lbs to LEO enables you to be able to launch a fully fuelled CSM with 12+ day independent endurance; along with an orbital module for extra workspace/cameras/scientific experiments without having to break out Saturn V.

[RyanC]

The MODAP Logistics CSM according to "Modified Apollo Logistics Spacecraft: Final Technical Presentation" (SID 63-1459) would have weighed 19,973~ lbs (*) and had the capability of:

6-Man Crew Transport to/from Space Station

6 Month Docked Stowage connected to Space Station

Transporting 7,157 lbs of cargo in cargo containers in four Service Module Bays where propellant used to be.

These containers would have massed 1,970 lbs. This would provide a 45-day resupply for a space station.

Cargo Bay Door opening would have been through using shaped charges on three sides, with the fourth side having hinges.

It sounds crazy, but a similar technique was used to blow off the SIM Bay on the J missions CSMs.

Cargo transfer would have been accomplished through using a mechanical arm to move individual containers into a smaller cargo transfer airlock on the station and/or via connecting a hose to allow for liquid cargo transfer.

[NOTE FOR * : This weight is for the spacecraft without cargo or cargo containers. Additionally, a 3,400~ lb Spacecraft Adapter would have been needed to adapt it to either Saturn IB or Titan IIIC.]

Significant changes other than reducing propellant tankage and cargo bay conversions that stand out to me are:

* SPS replaced with LEM Descent Engine. This would have cost the government only $95,000 USD versus $320,000 for SPS.

* Fuel Cells (1,450~ lb) were replaced with Batteries (600~ lbs). It's worth noting that NAA pointed out that if H2 boil off issues over six months of storage were resolved satisfactorily, a fuel cell system weighing only 320~ lbs could do the job.

* 570~ lb reduction in Heat shield mass due to lesser heating load from orbital re-entry vs lunar re-entry.

* Using a solid motor retro-rocket package similar to that on Mercury for orbital deboosting of the CM -- it would have massed 1,268 pounds. It makes sense; because you don't have to deboost the entire CSM -- just the CM. But this means additional R&DTE and further changes to the Service Module, so we can delete it and just eat the reduced cargo load if cost is a concern.

* Retros would have been added integral to the CM to allow a minimal earth-landing capability -- though water landing would still be the prime landing mode. This could be eliminated for lesser R&DTE.

If MODAP had been approved sometime in 1964, operational flights would have occured in July 1968; roughly some 55~ months after ATP.

Total costs to develop the MODAP CSM and provide 49 flight articles would have been $1,881 million in FY67 dollars; that's $12,280 million in 2010 dollars. Peak funding would have reached about $380 million a year in FY67 dollars ($2,480m in 2010 USD).

----------------

The above data provides us with a crude approximation of what a LEO-only Block III CSM would have been like if it had been decided to continue use of Apollo/Saturn technology in January 1972 instead of going with the Space Shuttle.

The biggest problem is going to be the delay that was imposed by the cancellations of 1968 and the time wasted until 1972 -- the last Apollo CSM delivered was Apollo 17's CSM-114 on 24 March 1971, and the production line would have shut down a bit before that delivery date; as subsystem providers finished out their contracts.

Once a production line has been shut down, even only for a small period; it's a pain to get it restarted again.

Development times for Saturn V variants ranged from 24 months for the INT-20 and -21, to 64 to 70 months for some of the more exotic variants; and those were assuming that a decision to develop them were made before Saturn V production shut down.

I think it's fairly safe to assume that even minor changes like implementing J-2S engines and simplifications based on  operational experience for a Block II production run of Saturn Vs would require 48 months from ATP.

Furthermore, even if we stuck to our guns and held the changes for a Block III CSM to a minimum, such as using developed subsystems, like the LEM DPS wherever possible; and keeping changes within reasonable bounds, such as a new Block III AGC that takes advantage of computing developments since 1964 to shrink weight, volume and power consumption, while offering more computing power, it'd be reasonable to assume it would still take 55~ months.

This would mean that it would take until December 1975 for Saturn VB lifting capability to be available to mission planners on a reliable basis; and July 1976 before manned flights can resume.

Hey, that's a good one for an alt-hist story -- the 4 July 1976 launch of the Skylab 5 Manned Reboost Mission from LC-39A, while LC-39B launches a few hours later the Viking nuclear powered rover for a landing date of 4 July 1977 on MARS.

Or why Saturn V/Centaur is awesome.

EDITED to clarify a bit more about a hypothetical Block III CSM.

[Proponent]

In reading about Saturn IB, there were a lot of replacements proposed, from solid first stages of single 260 inch monolithic motors to clusters of 120 inch motors from Titan III.  I don't think any of them were particularly realistic or even desirable.  Intuitively, the amalgamation of clustered tanks and small kerolox H-1 engines and heavy stage weight looks terribly inefficient, and in a way it is, but on the other hand, it was PAID FOR and design and development of a new system is VERY expensive!  From what I've read, the performance improvements of a "dual propellant tank" Saturn IB replacement probably wouldn't have justified the development costs in capability or cost savings over continuing with the standard Saturn IB.

The S-IB's clustered tankage wasn't actually as much of a drag on performance as people think, partly because the stage wasn't that amazingly heavy, and partly because first-stage weight isn't so important, since it's dropped early in flight.  Just for the fun of it, I've run some numbers with Schilling's Launch-Vehicle Performance Calculator for the proposed Saturn IB with J-2S-powered upper stage and miscellaneous weight reductions ("SA-217" in the attached paper).  Performance from Cape Canaveral to a 185-km circular orbit at 28.5 degrees is predicted to be 20,900 kg (not far from the value of 20,400 kg given in the attached paper).  Now lighten the S-IB's tankage by 7000 kg so it has the same structural fraction (7.4%) as the modern Atlas V 401.  The payload is now 21,700 kg, a gain of merely 700 kg for the shedding of 7000 kg of first-stage weight.  As you say, re-designing the first stage would not have been a cost-effective way of boosting the Saturn IB's performance.  Opportunistic weight reductions, engine improvements and second-stage stretches were better ways to go.

EDIT:  "again of" -> "a gain of"

[Proponent]

INT-21 is basically what launched Skylab, and had 75mt to LEO, and then obviously Saturn V had 110mt. to LEO.

http://en.wikipedia.org/wiki/Saturn_INT-21

I have a little trouble parsing Wikipedia's statement about the INT-21's LEO capability, but to the extent that it implies the capability was 75 tonnes it is incorrect.  The INT-21's LEO capability would have been about 255 klb = 116 metric tons -- see the attached paper.

Skylab did not make full use of the Saturn V's two-stage payload capability.

The S-IVB stage, though crucial to the Saturn V's TLI capability, added little to its LEO capability.

[Proponent]

Why would a replacement SIB stage need to use two F-1s? Why not just use one F-1A?

Indeed, I don't think two F-1s would be possible.  With an thrust-to-weight ratio of about two even at take-off, the acceleration would quickly become outrageous.

[Lars_J]

Yes a Saturn IB with a single F-1A powered first stage would seem like a great natural evolution. Was it ever seriously considered, or was Shuttle development started early enough that people just didn't consider it?

[RyanC]

the last Apollo CSM delivered was Apollo 17's CSM-114 on 24 March 1971, and the production line would have shut down a bit before that delivery date; as subsystem providers finished out their contracts.

I've been digging for information and found that my earlier information was incorrect. CSM-114 was ready at the factory for delivery on 17 March 1972.

Additionally, in SP-4011, SKYLAB: A CHRONOLOGY, it mentions that on 18-19 July 1972; the SL-2 CSM was shipped to KSC -- that was CSM-116. Generally the CSMs arrived at KSC a day or so after they were ready for delivery at the factory.

Unfortunately, I haven't been able to find further information on CSM-117/118/119.

This does indicate that the Apollo production infrastructure was not yet quite totally shut down by January 1972; which means that it's plausible to reduce Block III operational availability from ATP to about 48~ months.

(Remember, you need to give a bone to to the Space Industrial Complex; and being able to update subsystems from their basic 1966-1968 technology level to a 1972-73 technological level would be more interesting to the engineers than a simple re-ordering of Block II.)

[Kaputnik]

Why would a replacement SIB stage need to use two F-1s? Why not just use one F-1A?

A single F-1A would have 1.7 to 1.8 mlbf of thrust -- Saturn IB's S-IB had 1.6~ mlbf of thrust.

While going to a S-IC style tank architecture instead of clustering would save a lot of booster weight, you'd still have to unload mass from the Apollo CSM to put it into LEO. Well, that and you would not have a performance margin in case of an underperforming engine or one that cuts out early.

Also, having 86,000 lbs to LEO enables you to be able to launch a fully fuelled CSM with 12+ day independent endurance; along with an orbital module for extra workspace/cameras/scientific experiments without having to break out Saturn V.

I was under the impression that the design goal for F-1A was 2 million lb thrust at sl, although Mark Wade puts it at 1.8.
Surprisingly, it appears that a single F-1A would weigh considerably more than eight H1 engines- does this seem correct or do the published numbers not take adequate account of thrust structure etc?
Even if the redesigned first stage might not gain much performance, commonality of tanking with the SIVB and common engine with the larger Saturns ought to allow some costs savings. Plus the next generation SIVB, with the J2S, woudl have offered a significant performance boost.
Couple that with a cheaper and lighter CSM optimised for LEO, and it sounds like quite a useful vehicle.

The main advantage, I would see, is that your workhorse manned launched would utilise the same class of engine as you would need to one day return to the moon. Plus you have the reliability of one engine per stage.

[Lobo]

Basically this entire exercise is predicated on the idea that "shuttle will cost too much to develop; there's no sense in doing it on the cheap, so let's improve incrementally what we have and use that.  So I doubt that new twin F-1 booster stages can be justified, or new upper stages.  Streamlining the program, simplifying production of F-1, and incrementally improving and simplifying the construction of existing stages would seem the way to go.  S-ID mods could have been incorporated as an "incremental improvement" to the thrust structure of S-IC, so it's FAR more likely than any new S-IB replacement first stage. 

Later! 
OL JR

You might not have needed to mess around with the S-IB replacement stage.  You could get rid of it entirely.  The INT-20 could probably have used just two F-1's on the low end of it's range, and up to 4 depending on what it was lifting.
S-IC stages would have been made at a greater production rate for INT-20, INT-21, and Saturn V.  It's reasonable to think those costs per unit would have been coming down.
Probably a new thrust structure on the S-IC would be desirable, because the one to hold up to all 5 engines would be probably a lot heavier than you'd want for a 2 or 3 F1 engine config for medium lift.
So you maybe develop two thrust structures to fit the S-IC.  One that would have 3 engine ports in a row (it'd looks like the Saturn V, but with two outboard engines removed on opposite sides.)  The outter two units would gimbal.  THe center engine, if used, would not.  So if you had two F1's, they be on two outboard ports, opposite, both woulg gimbal.  You can add an 3rd center engine to it for more lift.
For the 4 or 5 -F1 config for ENT-20, ENT-21, or Saturn V, you'd have a thrust structure like the Saturn V had, but with the ability to drop the center engine.

So you have 3 LV's using the S-IC.  Two LV's using the S-II, and two LV's using the S-IVB.  All based around two engiens.  THe F1 and J2. (upgraded to F1A and J2S).

http://www.astronautix.com/lvs/satint20.htm

[Jason1701]

I'm confused about that page. Why would a 6g limit give less payload than a 4.68g limit?

[Lobo]

I'm confused about that page. Why would a 6g limit give less payload than a 4.68g limit?

Yea, I didn't get that either... 

[Proponent]

I'm confused about that page. Why would a 6g limit give less payload than a 4.68g limit?

The figures shown for the 4.68-g case appear to be in pounds rather than kilograms.  The Saturn V "A" derivative described in the attached report appears to be identical to the INT-20; 4.68-g and 6.0-g payload figures are given on page 5.

I've contacted Mark Wade about this error a couple of times.  Although he has replied to me on other topics, I've never received a reply on this topic.

[Proponent]

I was under the impression that the design goal for F-1A was 2 million lb thrust at sl, although Mark Wade puts it at 1.8.

Definitely 1.8 Mlb at sea level.  Two million pounds sounds about right for the vacuum thrust.  You can find F-1A docs on NTRS.

Surprisingly, it appears that a single F-1A would weigh considerably more than eight H1 engines- does this seem correct or do the published numbers not take adequate account of thrust structure etc?

Interesting, I hadn't noticed that.  The H-1D had a sea-level T/W of (204,300 lb) / (2003 lb) = 102 on the basis of engine dry weight (figures from the attached report), whereas the F-1's T/W was (1,522,000 lb) / (18,619 lb) = 81.7.  It was a famously conservative design in respects other than sheer size.  I haven't found a precise weight for the F-1A, but if it weighed the same as the F-1 the T/W would have been (1,800,000 lb) / (18,619 lb) = 96.7.  I suppose the F-1A might have been lighter than the F-1 and might have more or less matched the H-1D's T/W.

Incidentally, the H-1 document shows that the wet weight of that engine exceeded its dry weight by about 10%, and the burnout weight was between the two.

The main advantage, I would see, is that your workhorse manned launched would utilise the same class of engine as you would need to one day return to the moon. Plus you have the reliability of one engine per stage.

Given that the Saturn I twice demonstrated engine-out capability, I'm not sure that an F-1-boosted stage would necessarily have been more reliable than the original 8-engine version.

[Spacely]

I'm trying to do dig it up, but I recall a trial balloon floated in the mid-80s whereby Apollo CMs would be re-started to fly atop Titans.  I can't recall whether this was to replace Shuttle, or simply to serve as ACRVs.

[Patchouli]

I'm confused about that page. Why would a 6g limit give less payload than a 4.68g limit?

The figures shown for the 4.68-g case appear to be in pounds rather than kilograms.  The Saturn V "A" derivative described in the attached report appears to be identical to the INT-20; 4.68-g and 6.0-g payload figures are given on page 5.

I've contacted Mark Wade about this error a couple of times.  Although he has replied to me on other topics, I've never received a reply on this topic.

You'd probably want to keep the acceleration under 4.68 G anyway as not the over stress the payload or the launch vehicle.

[Archibald]

I'm trying to do dig it up, but I recall a trial balloon floated in the mid-80s whereby Apollo CMs would be re-started to fly atop Titans.  I can't recall whether this was to replace Shuttle, or simply to serve as ACRVs.

I've heard of that, too - "refurbished apollo capsules" was the term I remember. I think it was post- Challenger, when a kind of panic stroke Freedom designers.
Motto was now "we need a lifeboat, quick !" and tons of concepts were reviewed. I remember a thing called SCRAM that used the Viking aeroshell, and had very high G-loads.
Never knew if capsules were rejected on *serious* reasons -the high G-loads on an injured crew memeber - or because they were less *glamourous* than spaceplanes / lifting bodies (HL-20 to X-38).

How serious was the "injured crew member = runway landing" reason ? I mean that space station Freedom had lots of things hyped by NASA, things that did not survived into the ISS...

[Proponent]

You'd probably want to keep the acceleration under 4.68 G anyway as not the over stress the payload or the launch vehicle.

Yeah, that's exactly where the 4.68-G limit comes from:  it was the maximum acceleration that the original Saturn V needed to withstand.  Going to a 6-G trajectory would have required strengthening the vehicle at some considerable expense.

[PhillyJimi]

I think also adding some of the money spent on the ISS needs to be included for the early 90's into the 2000's. 

I am estimating building a Sat V every year or 9 months what ever make the most sense between production and costs.  In most cases the Sat V would no longer be used to lift astronauts.  I am also assuming the planned upgrade to the F-1A rocket motor happened to increase to 2 million lbf.  I am also expecting the defense department would also purchase a few Sat V flights to help with costs, if they had the capability I am sure someone would of thought up a few missions for it in 40 years, especially in the Star Wars era. I am expecting performance increases to all 3 stages over the 40 years of service. 

Sat 1-B, I am also assuming at some point the crew capsule would be able to be recycled or replaced with a small winged, dream chaser style capsule.  It would be the crew taxi to LEO.  Hopefully the costs would start to drop and stabilize. 

late 70's

Skylab 2 or expand the existing Skylab.  Change crews every 6 months.  At some point the Skylab module or 3rd stage fuel tank becomes a generic platform for human space flight and large science missions in order to lower costs.  Eventually partner with other nations in the future.

Do Apollo 18, 19, 20 & 21 (include a far side mission).  Slow the pace of the missions down cut the support crew down while also cross training the remaining crew for the new missions. 

80's Space Station Telescope

Launch "Sky Lab Telescope" to the L2 Lagrange point at the moon - A Skylab sized space station as a backbone for mounting space telescopes.  Include a small astronaut apartment for servicing missions.  It would maybe take 3 or 4 Sat V launches but it still could be in use today and would be upgradeable and expandable.  Just imagine the size of the telescope that could be launched with a Sat V.  Or it could be an array system consisting of 10, 30" inch telescopes working together or as individuals.  Crew would dock with the station and live in the crew quarters.  Servicing could be done via space walks from the crew quarters.  Launch a servicing missions as needed.  Add a major part every 5-10 years on a crewed Sat V.  The science could grow at a reasonable pace rather then trying to take giant steps every 20 years. 

Major Deep space science probes are launched on a Sat V.  They can be more robust and more capable due to being able to throw more hardware.  Including more probes like the Huygens probe for Titan.  Start with the stage 3 fuel tank, standardized this platform or backbone should lower costs and make weight less of a concern considering we have the big gun to shoot it out into space.  With something like this landing probes on the moons of Jupiter becomes doable. 


90's - Moon base or Mars Mission? 


Considering Skylab or SkylabX has been flying for so long we don't need to build another space station.  Of course keeping a space station going is going to cost money so not all of the ISS funds get freed up to spend in the 90's and 2000's. 

Mars Part I - Flyby

I think a flyby of Mars and landing on one of the Mars moons would be the first logical steps before actually landing on the surface. 

I am proposing 2 or 3 Sat V launches launch a skylab sized habitat module and a 2nd skylab sized module but have this one be the propulsion module with fuel and extra water.  Maybe a 3rd flight to fuel it.  Mate them in orbit.  Fly the astronauts up in a 1-B and have them fly off to Mars.  Spin it to create some gravity.  Include a bunker in near the propulsion module and water for any solar storms.

Mars Part II - Landing on Phobos or Deimos with a practice landing on the Earth's moon. 

Do it again but this time with an  extra Sat V launch with the hardware for a Mars moon lander.  Land on a Mars Moon.

Mars Lab 1 Sat V launch - Land the experiments to establish living off of the surface as much as possible.  Breaking the CO2 into usable O2 for breathing and for rocket return fuel.  Try growing plants in a greenhouse.  Get very good at very precise landings. 

Robotic Mars landing - Generate our own O2 fuel and blast back off with a soil sample. 


2000's

Mars Landing and/or establishing a colony on the moon first? 

Land the most of the hardware a year before we launch the men to use it. 


2010's

We would also tell some of the experts who would want to trash our old Apollo era technology for a large reusable shuttle.  We would tell them that didn't work in the 70's and it still won't work today.  The people arguing that the Apollo rockets are the same technology as to what the Russians are still using it is time to move forward or in 35 years we'll still be stuck in time like the Russians are now in 2011 with no real capabilities, how depressingly sad would that be! 

Sure maybe some of this might require more money they the STS and the ISS combined but considering NASA just got about $500 million to study the gravity of the Moon, I think these kinds of programs are exciting enough to keep the public engaged and funding it.