NASA Study Summary: "Performance of Low Cost S-IVB with UA-1207 SRMs LV"

[luke strawwalker]

Here's an interesting study in the "alternate Saturn derived vehicles" category from 1970 entitled "Performance of Low Cost S-IVB with UA-1207 Solid Rocket Motor for Interim Launch Vehicle" by Bellcomm, Inc. It proposed to use a cluster of UA-1207 Titan IIIC 120 inch SRMs for a first stage, but unlike many other proposals which used the S-IVB as a second stage, this one used either a single or pair of UA-1207 SRMs for a second stage, either underneath or flanking either side of the S-IVB used as a third stage. This could orbit some substantial payloads, upto over half that of Saturn V, and WELL beyond Saturn IB capabilities, if you could get past the clustering of massive numbers of large SRMs (and the infrastructure impacts, which weren't addressed at all). This vehicle was designed as a temporary stand-in from the termination of Apollo until the Shuttle became available, and presumably make it obsolete.

It's an interesting idea and would certainly make an interesting model, especially some of the larger versions, and especially if they were made with separable boosters... LOL

Enjoy! OL JR

[luke strawwalker]

Pic one is of the various configurations studied in this report. It shows the combinations of UA-1207 120 inch SRMs used to make up the first and second stages of the vehicle, topped by a 'cheap' version of the Saturn IB/V S-IVB stage acting as a third stage. Some of the configurations placed the second stage airlit SRMs on either side of the S-IVB, some placed them directly below it, surrounded by the first stage SRMs which would be dropped at staging from around it...


Pic two is a closeup of configs 1-5... the configuration designations beside it, like 4+1, is the number of first stage SRMs and the number of second stage SRMs. How they figured on supporting nearly a million lbs each of SRM on either side of an S-IVB would have been interesting to see...


Pic three is the larger configs 6-10... most of these exceeded the 740 psf max-Q limits of the S-IVB structure. No mention was made of structural beef-up required to the S-IVB to handle the thrust of this many SRMs at liftoff or the weight of a massively larger payload on top than the Saturn V stack handled...


Pic four is a chart showing the performance of the various configs, and an "end view" of the stack showing how the first and second stage SRMs were to be arranged, along with the third stage S-IVB. Some of these were pretty impressive capability-wise, if the problems inherent in such designs could have been affordably overcome... Of course no mention or consideration of this problem was given in the report...


Later! OL JR

[Bill]

To think that somebody got paid to sit around and dream up stuff like this...


Bill

[luke strawwalker]

This one is basically BOTE (back of the envelope) stuff-- for instance, NO mention is made of how you just "magically" get two 120 inch SRMs (calculated the base weight from a chart I posted in another thread) weighing 620,130 lbs EACH to hang off the side of and S-IVB for a second stage without a SUBSTANTIAL support method, ESPECIALLY under high acceleration Gees and high max Q dynamic drag pressures... This just TOTALLY doesn't pass the sniff test. That weight isn't even figuring in the additional weight of equipment and tankage and steering fluid for the SRM nozzle liquid steering fluid injection TVC system required for TVC on the second stage SRMs--

SO this was totally "blue sky" thinking... which is good; nothing wrong with that, but it's not hard to see why this never got any traction at all... NASA couldn't really afford to do shuttle (right) and certainly couldn't have afforded a new three stage LV, even if based on existing hardware such as S-IVB and UA-1207 SRMs, that was such a radical departure from existing engineering and would therefore require a LARGE development, testing, and engineering program and a complete qualification program as well.

I think the three SRM cluster first stage topped with an S-IVB capable of 50,000 lbs of payload would have been a MUCH more likely vehicle, and the engineering would have been quite simple compared to some of these behemoths... nevermind the fact that you could simply launch three of these smaller beasts to orbit your 150,000 lb payload instead of one single "mega SRM launcher" like this to do the same thing-- and then the factor of "what payloads" starts to rear its ugly head-- which is a nagging question that more and more demands attention with some of NASA's current plans (SLS), just as it did for Ares before it... when the payload development gets cancelled to provide funds to develop the boosters, does it really even make sense to develop the booster anymore?? After all, why develop the launcher if you can't afford payloads to put on it?? The 70's were dark times; there wasn't money for shuttle and payloads too, let alone a second booster system-- basically that's been the KILLER in NASA since the end of the Apollo/Saturn programs... NASA could never afford an HLV alongside shuttle, despite some interesting proposals for it (Shuttle C, NLS, Big Dumb Booster, etc) which would have had obvious uses, especially when it came time to build the ISS... but NASA couldn't afford it. Neither will it be able to afford not ONE new booster but TWO-- which is what (IMHO) doomed Constellation from the starting gate-- requiring TWO rockets to do the job instead of a single common design launched more often, raising flight rates and therefore amortizing overhead over a greater number of launches.

Back to the vehicle proposals in this thread, personally I'd like to have seen a version with a cluster of UA-1205/1207 SRMs SURROUNDING a lengthened and substantially beefed up S-IVB, which would have formed the core vehicle-- sorta like a mega-sized Delta II but using the beefed up S-IVB for a core stage and clustering the UA-1205/1207 boosters from Titan IIIC around it instead of the much smaller Delta boosters... have some of those airlit for a second stage-- perhaps cluster eight of them around the S-IVB, with the two on either side airlit, and the three between them on the front and back groundlit for liftoff, and shed mid-flight much like Delta II, but shedding three adjoining boosters on the front and back of the rocket, leaving the two opposite flanking SRMs to airlight for a "second stage". It would look much like this rocket proposal below, but using the S-IVB instead of the S-II stage... technically speaking, the S-IVB wouldn't even have to be lengthened-- a cylindrical "interstage" or trusswork spider beam type structure could have linked all the bottom ends of the boosters together and provided a lift point for the S-IVB above it, dropped like the S-IB interstage after the two "second stage" flanking SRMs were dropped after burnout, just prior to J-2 startup on the S-IVB. That to me would have been a MUCH more likely configuration than placing the flanking SRMs 'up top' with the S-IVB, and would have avoided the problems with the possible instability of placing the paired SRMs directly below the S-IVB (which I don't think would have really been a problem; certainly not one that couldn't have been worked around... )

Anyway, it's an interesting "what could have been"... even if quite unlikely...

Later! OL JR :)

Pic one below would be what "my" proposal would have looked like, except with a S-IVB in the middle instead of an S-II stage, and surrounded by 6-8 UA-1205 or UA-1207 SRMs like a gigantic version of Delta II...

Pic two is the obvious study predecessor to the "single center SRM single stage" version mentioned in the study-- if the center engine on the 'alternate' clusters had been airlit with the other 3 or 4 surrounding it groundlit as a 'first stage' and then dropped off at burnout like a Titan IIIC. Taking it to a pair of SRMs for the second stage and adding more "stage zero" SRMs clustered around it was just a "logical next step".

Pic three is sort of the version I consider to have been most likely-- though this is a graphic of the old Very Large Solid Rocket study by GCR in '61, and a three stager depending on the 4 J-2 260 inch second stage that never existed (morphed into the 5 J-2 396 inch S-II for Saturn V is more correct). I'm thinking more of the same triangular 3 SRM cluster of 120 inch UA-1207 boosters for the first stage lofting the S-IVB as second stage... wonder what it would have done as a three-stager with a six-RL-10 engine S-IV stage on top of the S-IVB (assuming the thing wouldn't have been badly under-thrusted by using a single J-2 engine on the second stage "stock" S-IVB...)

[luke strawwalker]

I knew there was SOMETHING about some of those big clusters of boosters around a pair of airlit upperstage SRMs that I liked...

Reminds me of the "Tantive IV" from Star Wars... LOL:)

Cool! OL JR :)