NASA Study Summary: "SATURN V DERIVATIVES"(1968)

[luke strawwalker]

Here's a brief study (more like a white paper) from 1968-- "Saturn V Derivatives". Much of what it discusses has been covered in other studies, such as the INT 20 and 21 vehicles, and the uprated Saturn V with 4 SRM boosters strapped on the first stage... BUT there is ONE concept that I've not seen anywhere else before... The "Saturn S-ID".

This concept vehicle would have taken a standard S-IC Saturn V first stage and totally reworked the thrust structure, to turn it into a 3 or 5 F-1 powered "MEGA-ATLAS" of sorts... The rocket would lift off under the power of all it's F-1 engines (3-5 depending on the payload) and fly normally until 70% of the propellants were gone. The outer 2 or 4 engines would shut down, their fuel valves would close, and then the outer skirt and thrust structure, with the fins and fairings, would jettison. The center engine, attached to a conical thrust structure at the base of the S-ID stage, would keep thrusting and push the entire S-ID stage with it's payload to LEO. The payload capacity would have been 50,000 lbs with the five engine variant. Basically, shuttle size payloads, with no shuttle-- only a single S-ID stage! The outer ring of booster engines could have theoretically been made recoverable (though no discussion was made of this in this study, but it mentioned a Boeing study that fleshed out the concept). The payload would have been even greater had the stage fuel tanks been enlarged.

Another "what if" that never happened but should have...

Here's the summary, and the pics to follow...

More to come! OL JR

View attachment NASA STUDY SUMMARY- SATURN V DERIVATIVES.txt

 

[luke strawwalker]

Ok... the first pic is the Saturn V derivative family... the first vehicle is the regular Saturn V, capable of orbiting 275,000 lbs. The second vehicle is the "A" vehicle (S-IC/S-IVB) capable of orbiting 132,000 lbs. The third vehicle is S-ID stage and a half to orbit concept, a modified S-IC with the new thrust structure, capable of orbiting 50,000 lbs (about 2/3 more than Saturn IB). The fourth vehicle is the "C" derivative, which takes the S-ID stage and a half and adds an S-IVB stage on top, capable of orbiting 180,000 lbs. The fifth vehicle is a beefed up S-IC or S-ID based vehicle with beefed up S-II and S-IVB stages and perhaps a propellant tank stretch, to handle 4 SRMs, in this case, 120 inch Titan III-C SRMs, capable of orbiting 400,000 lbs. The sixth vehicle is the same vehicle as the last one, but strengthened and fitted with 156 inch SRMs, capable of orbiting 500,000 lbs. The last pic is the same vehicle strengthened to handle 260 inch SRMs capable of launching 700,000 lbs. to orbit...



The second pic is the "A" vehicle... pop the center F-1 off the S-C, plug the lines, slap the S-IVB on top, presto there ya go. Instant 132,000 lbs to LEO or 32,000 lbs to the moon. "SEO" is geosynchronous orbit.



The third pic is the "B" vehicle, or S-ID. Basically rework the thrust structure by mounting the center engine on a cylinder attached to a new conical thrust structure on the back of the stage, to transfer the thrust to the vehicle skin. Rework the outboard engine thrust structure cross beams with a cylinder in the center large enough to clear the center engine, by removing the cruciform where the center engine USED to be mounted. Make the aft structure seperable from the fuel tank/new thrust structure joint where the outboard engines transfer their thrust to the vehicle structure, install seperation devices into the propellant lines so they can sever at staging and fall free, install gimbals on the center engine and rework the IU in a 33 foot ring to fit the top of the stage, and to handle the vehicle modes for proper control, and presto- instant 1.5 stage to orbit "mega-Atlas" capable of orbiting 50,000 pounds without an engine upgrade or tank stretch. Do the tank stretch and you up the payload. Uprate the F-1's and you REALLY up the payload!



The fourth pic is the "C" derivative-- put the S-IVB on top of your new S-ID stage, and presto-- 180,000 lbs to LEO, or 45,000 lbs to the moon.



The fifth pic is the "D" derivative, the actual "upgrade" beyond Saturn V. This is pretty much what was discussed in the other uprating studies in more detail. Strengthen everything quite a bit, stretch the propellant tanks, and slap on 4 SRMs of your favorite flavor-- off the shelf 120 inch Titan III-C boosters, 156 inch SRMs, or the 260 inch SRMs tested by Aerojet as possible first stage replacement for Saturn IB.



More to come... OL JR

 

[luke strawwalker]

Ok... the first pic is a chart from the study... I know, doesn't have much to do with modeling the thing, but it does shed some insight into some of the conclusions and thinking... this one has a lot going on... The solid curved areas at the top of the chart are the performance envelopes of the various SRM equipped Saturn V's. Moving DOWN the chart, toward the curved line at the bottom of the 'wedges' created by the lower line, the lower line shows the maximum core propellant tank stretches beyond which no further increase in performance occurs. The left edge of the chart shows the maximum payload envelope size for the vehicle, which of course gets shorter as the fuel tanks get longer, with the 410 foot height limit being fixed. As you move from left to right, you can see the increase in payload capability to LEO, as shown at the bottom of the chart. The width of the 'wedge' for each vehicle shows the increase in payload capability starting on the left with a basic unchanged (but beefed up) Saturn V with the SRM's, to the full tank-stretched beefed up Saturn V with the same SRM's at the lower right, or "point" of the wedge. Each step to the right is going up to the next largest size SRM, from the 120 inch, to the 156 inch, to the 260 inch. The dotted line defines the same fields and values for the vehicles, if they ALSO incorporated the uprated liquid engines in the stages, the F-1A and J-2S.
As I said, a LOT going on in this chart, but you can also "pick-n-choose" your favorite variant and favorite options and see what the performance would be... quite interesting graph and a TON of information in it! Even shows how much you can stretch the tanks before you hit diminishing returns.



The second pic is the development cost picture for all the variants... if done piecemeal one at a time, versus a combined project doing all the work at once and qualifying all the vehicles at once, which was actually cheaper...



The third pic is an artist concept of the S-ID at staging. It reproduced with almost UNUSABLE quality, so I sent it over to Paint and reworked it into something actually viewable. Not perfect but 'good enough'...



Well, that's it for this one...

Later! OL JR