NASA Study Summary: Selected Methods for Uprating Saturn Vehicles (1966)

[luke strawwalker]

Hello again! Here's another study summary I completed last night. It's entitled "Selected Methods for Uprating Saturn Vehicles, from June 1966. Unfortunately the graphics with this one are of very poor quality, for whatever reason-- I don't think they were particularly good to start with, and storage issues may be part of the problem or duplicative fading (every time you make a copy of a copy, errors are introduced and repeated and original data is lost). Or this may have been a poor (but only existing) copy to start with. I dunno...
It may also be more akin to a "white paper" like those submitted for conferences like AIAA nowdays instead of a true "study report" to NASA HQ or a particular center or technical branch like most of the other studies I've summarized.

AT any rate, it's not a particularly long study, but most of the information in it is relevant to the modeler and is in the summary. The various vehicles are ranked by their performance levels, so you can see what upgrades would have been most likely or had the greatest impact on improving Saturn performance, or which were 'overkill'... there's some discussion of FLOX propellants and even a HYPERGOLIC FUELLED S-IC stage, but a lot of the stuff here goes hand-in-hand with the stuff posted in the last Saturn Improvement Study I posted.

The most interesting NEW thing I've seen in this report and not in others are the proposals for a SRB-BOOSTED GROUND-LAUNCHED S-II STAGE launch vehicle. Basically, it's a modified S-II Saturn V second stage, flanked by four 120 inch Titan III-C SRMs, which act as a 'zero stage' at liftoff, carrying the liquid-powered stage to altitude before it ignites it's engines, which greatly increases the payload capability and efficiency of the rocket, identically to how Titan III/IV 'zero stage' did it. The other innovation mentioned specifically in this report that I have not seen before is the proposal to create a "milkstool" so that the ground launced S-II vehicle could be launched off the same pad as the Saturn V. While this proposed ground launched S-II never was developed, the "milkstool" WAS used to launch Skylab Saturn IB's from the Saturn V MLP's at SLC-39 to provide the exact same 'interface height' for the S-IVB second stage of Saturn IB at the same levels as the interfaces servicing the S-IVB on Saturn V. This proposal was for a milkstool that would basically duplicate the height of the S-IC stage (so it would have been taller than the milkstool used with Saturn IB) while supporting both the S-II stage and the 4 Titan SRB's on the sides of the S-II.
There are a couple of 'graphics' (pictures hardly seems appropriate given the poor quality) that were SO badly damaged as to be virtually unrecognizable, but with some judicious 'reconstruction' in "Paint" I managed to pull them back together enough to illustrate the idea.

Here's the report summary... More to come! OL JR :)

[luke strawwalker]

Ok... the first pic is sort of a graphic showing the various permutations of combinations the study looked at... from upgrades to the existing Saturn vehicle engines, to new advanced engines like HG-3, to various solid and liquid rocket booster options... See the poor quality and low-budget effect of the 'shadow graphics'...

The second pic is a chart showing the growth potential and performance of the Saturn IB vehicle with various modifications, and at the high end, various types and numbers of SRB's attached to it. None of these were particularly likely to ever be developed, as they'd be WAY too costly for the performance gains possible...

The third pic is graphically illustrating the definition of the "intermediate vehicle" range, that is, that area of performance NOT covered by upgraded Saturn IB's compared to the performance of the base Saturn V. Basically, the "ultimate upgrade" to Saturn IB could only lift 150,000 lbs to orbit, and the BASE Saturn V vehicle (off-the-shelf) could lift 250,000 lbs to orbit, so to carry payloads in this 'intermediate range' would require either "SUPER-MODS" to Saturn IB (which would never happen due to costs) or "downgrades" to Saturn V to accomplish the mission. These "downgrades", either through engine number reduction (not installing 1 or more F-1's in the first stage, or 1 or more J-2's in the second stage), or stage deletion (not using the third stage but simply placing the payload on top of the S-IC/S-II stack (like Skylab) or putting the S-IVB with the S-II Interstage directly on top of the S-IC first stage and deleting the S-II stage) or a combination of these two methods would have filled the 'intermediate region' performance gaps quite nicely while increasing the number of flown stages (which is important for getting per-unit costs down, and therefore $/lb to orbit costs down).

The fourth pic is the "Intermediate Vehicle" range with the cadidate configurations and their performance charted from least to most performance. Note the two-stage S-IC/S-II combination used to launch Skylab here, as well as the combination S-IC/S-IVB vehicle, on down to the various "ground launched S-II combinations" using various types and numbers of SRMs-- one variant using new engines in the S-II stage without SRM's (probably a fairly large cluster (7?) HG-3's. Minuteman ICBM first stages were also proposed for fairly low-thrust, short duration "JATO type" SRBs, but this wasn't particularly realistic-- the same money spent on manrating and modifications for mating UA-1205 or 1207 Titan III SRB's with the S-IC or S-II stage would have had FAR more "bang for the buck" than messing with the relatively low thrust and short duration Minuteman motors, which would require LARGE clusters to accomplish much performance gain (and therefore would have COMPLETELY TORPEDOED the 'safety numbers' (interesting how the 'reliability and safety numbers' aren't even discussed in these OLD reports!:))

The fifth pic appears to be a duplicate... maybe from another source or part of the report...

Later! OL JR :)

[luke strawwalker]

The first pic is a reconstruction of the GROUND LAUNCHED S-II proposal, with 4 UA-1205 or 1207 Titan III-C/Titan IV SRBs attached directly the sides of the modified S-II stage. Note the stage skirt attached to the base of the stage for an aero-fairing and attach point for the SRBs, and presumably there would be modifications such as a spider beam attached to the top of the stage to attach the fwd points of the SRMs to the stage. The J-2 (or HG-3) engines could be either lit at liftoff (which wasn't particularly beneficial since the J-2's (and presumably the HG-3's as well) were designed with high-expansion nozzles for vacuum operations at altitude, and would have been WAY over-expanded for use at sea-level-- probably requiring redesign for ignition at sea-level... Much MORE likely is that the rocket would leave the pad under the power of the 4 120 inch SRM's for the first two minutes of flight, and the J-2's would have been ignited shortly before burnout and seperation of the SRBs. Several variants of this rocket were discussed, including versions with the S-IVB installed acting as a "second stage" ala Saturn IB, which would actually have been a 2.5 stage vehicle when considering the SRBs used for liftoff. The other proposal was simply using the S-II as the upperstage with the SRBs acting as a "zero stage" or half-stage, providing the liftoff thrust and then the S-II carrying the payload to sufficient altitude and velocity that it could inject itself into orbit and circularize that orbit with the apogee burn. The vehicle concept in the picture is of this type-- 4 120 inch SRMs lifting the modified S-II stage, with an S-II/S-IVB interstage on top to reduce the diameter from 396 inches of S-II to the 260 inches of S-IVB, then bolting the 260 inch IU directly to the S-II/IVB interstage, with the spacecraft adapter panels (which usually covered the LM on Saturn V flights) used to cover whatever payload was carried (if any) and adapt and attach the Apollo spacecraft on top of the stack. This would have required the addition of another 'white room' and access arm to the pad to service this vehicle, even atop a milkstool, due to the deletion of the S-IVB stage and subsequent difference in height. If such a vehicle had become a common crew launch vehicle, then a new MLP/tower may well have been built to purpose-serve this vehicle at a lower height than a modified Saturn V tower would have allowed... Of course for unmanned payload launches, a 33 foot diameter payload fairing could have been developed, (which would have required either a new 33 foot IU or mods to attach the 260 inch Saturn V IU directly to the top of the S-II stage inside the fairing) or the S-II/IVB interstage attached atop the S-II (with the standard IU attached directly atop it) with the payload attached directly atop that, either with it's own fairing/nosecone or a 260 inch encapsulating fairing on top of that... similar to that which covered Skylab's front end with the Apollo Telescope Mount and docking module during liftoff and early flight.

The second pic is such a modified ground-launched S-II cargo vehicle, apparently with a 33 foot diameter payload fairing/nosecone, sitting atop the "milkstool" which was the REAL point of the illustration here... the vehicle is more 'notional'... hence why I didn't go into a HUGE amount of work to completely fix the picture like I did with the one above... (and really, I had VERY little to work with-- the last pic was intact enough to see what the thing really looked like, but had a lot of spots and missing line segments that I went into Paint and corrected-- this one was so messed up it was sort of hard to distinguish between "spots" on the picture and the actual lines of the drawing which were missing so many parts as to appear as disconnected "spots") It's good enough to get the general idea though...


The third pic is the Saturn V growth spectrum, with the various configurations graphically represented with their performance levels for easy compare/contrast. The larger Saturn V upgrades would have used the 156 inch SRM (was that ever developed or just test items/notional?? Have to research that) and/or the 260 inch monolithic SRM proposed for a Saturn IB replacement first stage (not particularly likely-- infrastructure difficulties in handling/stacking such stages would have been EXTREMELY expensive to implement for Saturn V boosters, and the thrust levels and acoustics impacts would have probably prevented their use at LC-39... requiring either a new offshore launch pad or something like that... and IIRC the pads themselves were only designed to handle 11 million pound of thrust (or was it 14 million?) so that bad boy would have probably required a complete rework of the pads to resist that level of liftoff thrust and handle that much weight anyway-- which would have been EXTREMELY expensive! The best alternative was using 260 inch Liquid Rocket Boosters (LRBs) each fitted with a pair of F-1 engines. This would have required either a new MLP or a complete rework of the Saturn V MLP/LUT but would have been crawler-transportable since they're moved empty (unlike the SRM proposals that would have required pad-stacking the SRM's due to the weight, which meant a whole new crawler-transportable SRM mobile stacking facility would have been required, moved to the pad after the Saturn V core vehicle was delivered atop the MLP/LUT to the pad from the VAB, which then would have covered and provided heavy-lift crane capacity to stack the SRBs on the pad and attach them to the Saturn V core vehicle, and then the SRM Mobile Stacking Facility would have been transported away by the crawler much like the Mobile Service Tower used on Apollo was.) LRB's would have eliminated all this, but would have been more expensive on a per-unit basis due to the more complex liquid engines, tankage, and structures. Of course such an LRB COULD have been used as a first stage for Saturn IB had the proper design and modifications been incorporated in it's development.

Finally, the last pic is probably one of the most interesting and bizarre graphics I've seen in any of these reports-- the "Ever Increasing Saturn V". The proposals for the most extreme heavy-lift configurations for Saturn V are here... from the relatively 'tame' proposals for an additional four twin-F-1 engined LRBs attached to a beefed up Saturn V core vehicle, to the nuclear third stage options discussed previously in other studies, but then the last configuration is for a MEGA-SATURN vehicle capable of over a million pounds to LEO... it would utilize four TWO-STAGED LRB's flanking the core vehicle and supporting most of the additional thrust and weight loads and aero forces, and would lift off under the presumed thrust of 13 F-1 engines in the Saturn core and 4 LRB first stages, presumably the LRB first stages would have been jettisoned along with the Saturn core first stage, and the second stage engines of the core vehicle and four booster upperstages ignited, then those five second stages would be discarded and a NEW THIRD STAGE, MUCH larger in diameter than the 33 foot Saturn V first/second stages (probably about, at a MINIMUM, 76 feet in diameter, and more likely about 80-83 feet in diameter, large enough to cover the combined first and second stage assemblage of 33 foot core stages flanked by 4 21.6 foot booster stages, assuming such a vehicle would have even been controllable from a 'fuel sloshing' perspective or buildable and transportable in the first place, or even desirable-- it's probably more likely a smaller 'hammerhead' design with an upperstage of at most between 40 and 50 feet would have been designed had such a variant EVER been given serious consideration, and that smaller third stage would have had either an aero-fairing covering the second stage booster tops and tapering down to the diameter of the third stage (much like the way the cluster of tanks and spider beams were 'tapered down' to the smaller 221 inch diameter of the S-IV stage on Saturn I Block II, or sorta similar to the conical interstage used to adapt the 396 inch S-II stage down to the 260 inch S-IVB stage on Saturn V), or the other possibility is that they would have used an 'inverted conical frustrum' interstage (like Ares I) to adapt the larger third stage to the 396 inch Saturn V second stage, with the 260 inch booster second stages equipped with nosecones similar to the Titan III SRBs or shuttle SRBs, flanking the second stage of the booster, with the inverted conical interstage nestled between them (ala Soyuz booster). Of course such a massive booster and the "Rube Goldberg" quality of it would almost certainly NEVER seen the light of day, even had such a HUGE lift capacity been a requirement... there would have been more straightforward and easier to achieve plans to get such performance without resorting to a monster like this... but it IS an interesting idea and would make a WEIRD model!

Later! OL JR :)