Reusable Saturn V

[Carreidas 160]

The Saturn V rocket saw many improvements over its lifetime. If it remained in service after Apollo and Skylab as a heavy lift vehicle, who knows what it could have evolved into?

In perfect hindsight, could a simplified design be applied to Saturn V to make it cheaper to operate and potentially reusable?

My own thinking on this was to have a 2-stage RP1/LOX vehicle by adjusting the Saturn V as follows:
- Keep the first stage, extend it if necessary.
- Make F-1 engines restartable.
- Add landing legs.
- Replace the second stage with a RP1/LOX fueled, F-1 Vacuum powered engine, based on the 1st stage. (Imagine how big a F-1 Vac would be

Thoughts?

[hkultala]

The Saturn V rocket saw many improvements over its lifetime. If it remained in service after Apollo and Skylab as a heavy lift vehicle, who knows what it could have evolved into?

In perfect hindsight, could a simplified design be applied to Saturn V to make it cheaper to operate and potentially reusable?

My own thinking on this was to have a 2-stage RP1/LOX vehicle by adjusting the Saturn V as follows:
- Keep the first stage, extend it if necessary.
- Make F-1 engines restartable.
- Add landing legs.

Would not have been able to land due:

1) Too much thrust(F-1 does not have pintle injector, cannot throttle down as much as merlin, and only 5 engines means much higer T/W with one engine)
2) Control algorithms and computers not good enough. these have advanced in the last 50 years quite much

Either using parachutes to soften water landing or adding wings for flyback were the possible options for reusable S-1C.

- Replace the second stage with a RP1/LOX fueled, F-1 Vacuum powered engine, based on the 1st stage. (Imagine how big a F-1 Vac would be

This would hurt payload capasity by a lot, not a sensible change.

[AS_501]

I'm not the expert that Jim is on these topics, but I suspect the great size of the Saturn V would make a Falcon 9-style legged landing impractical or cost-prohibitive, if nothing else.  However, there was a proposal for winged a "Fly-Back" S-1C for an early, all-reusable Space Shuttle system.  If the Apollo program had not been cancelled, one wonders if at least some economies could be introduced that could have at least brought down launch costs.  I think there is another NSF thread out there on what a continued Apollo-Saturn system might have become.

[Antilope7724]

Here is an interesting video of a Saturn-I first stage, 1/12 scale model, air-dropped in a deployment test of a parawing recovery system, in 1963.

[Generic Username]

There were *many* proposals for reusable Saturn Vs, specifically reusable S-IC stages. There were a number of manned, winged flyback boosters like the Boeing Models 922 and 979 (http://aerospaceprojectsreview.com/ev1n2.htm), and similar designs from McD and NAR; there were also designs for parachute recovered (via splashdown) as well as balloon-retarded versions (including hot-air versions meant to provide enough buoyancy to actually float in the air, good for recovery directly onto the deck of a ship).

[RanulfC]

S1C proposal recovery down-range water landing brochure:
http://www.collectspace.com/ubb/Forum29/HTML/000880.html

Randy

[Proponent]

If you want something more technical, here's a 1963 study of parachute recovery for the S-IC.

[RanulfC]

If you want something more technical, here's a 1963 study of parachute recovery for the S-IC.

Hmmm, uses a toroidal parachute and lands engines first which is opposite of most other methods I've seen. You pretty much wanted to avoid landing on its engines even in water
Thanks.

Now if I could find some studies on the Saturn-1/1B recovery...

Randy

[Proponent]

Now if I could find some studies on the Saturn-1/1B recovery...

EDIT:  Added second report, on paraglider materials.

Scott Lowther also sells a Ryan report on recovery of Saturn first stages by paraglider, which I won't attatch, because I don't want to undercut his sales (his price is very reasonable).

[malenfant]

I'm not yet convinced that a reusable propulsive landing s1c was out of reach of 1970s tech.  Surveyor and viking demonstrate sub sale propulsive landing.  IIRC then I think warheads were reaching 1km accuracy at that point; a 1 km diameter pad is plausible.  For the T/W problem then replace the outboard engines with f1a and replace the centre engine with a cluster of redesigned, thottlable H1s (or reactivate E1 development?).

None of these are small challenges but are they significantly harder than building the shuttle?

Strikes me that the real reasons are that the prevailing culture was biassed in favour of wings and that government was determined to kill S1c anyway (or not to revive it).

[simonbp]

S1C proposal recovery down-range water landing brochure:
http://www.collectspace.com/ubb/Forum29/HTML/000880.html

Randy

I really like that idea. If it were combined with a few small solid landing rockets triggered by a radar altimeter (to keep the F-1s from getting too beat up when hitting the water), that is probably the plausible scheme I've seen for a reusable S-IC.

[RanulfC]

Now if I could find some studies on the Saturn-1/1B recovery...

EDIT:  Added second report, on paraglider materials.

Scott Lowther also sells a Ryan report on recovery of Saturn first stages by paraglider, which I won't attatch, because I don't want to undercut his sales (his price is very reasonable).

VERY reasonable, very well done and researched information, his cause is just, EVERYONE BUY SOMETHING FROM HIM RIGHT NOW! (Maybe classified as a blatant plug )

Thanks, this gives me some mass estimates to work with Strange that all the methods are still "engine-down" on landing when the S-1 was designed to land "stage-interface" down with retro-rockets for final velocity damping.

I'm not yet convinced that a reusable propulsive landing s1c was out of reach of 1970s tech.  Surveyor and Viking demonstrate sub sale propulsive landing.  IIRC then I think warheads were reaching 1km accuracy at that point; a 1 km diameter pad is plausible.  For the T/W problem then replace the outboard engines with f1a and replace the center engine with a cluster of redesigned, thottlable H1s (or reactivate E1 development?).

Boost back (or forward as its "landing point" was quite a ways out into the Atlantic) would have required more propellant and meant a loss of some payload capacity. Then there is all the landing equipment, (gear, guidance and sensors, etc) which reduces the payload even more. Given the constraints of required payload to a certain orbit for lunar missions (the 'reason' for the Saturn-V in the first place and its main mission) I don't see it happening.

Yes throttling the F1 enough to land would have been a major problem and replacing the center engine with a cluster of H1s (you'd need about 8 of them to be exact to match the take off thrust of the F1s used for the later Apollo missions, 9 for the F1A) where would you PUT them? You MIGHT be able to fit nine H1s on the S-1B stage (the S1B was a little over 6m in diameter) but the F1 itself was only 3.7m at its widest (nozzle) so there's really no room for that many H1s on the S-1C stage. Restarting the E1 development program is possible but unlikely given the budget environment at the time. Where would you land the stage is probably more important.

None of these are small challenges but are they significantly harder than building the shuttle?

Probably not but a better question is how is the suggested propulsive return/landing "better" than landing at sea and recovery or finding a way to return the booster back to the launch site by non-propulsive means?

Strikes me that the real reasons are that the prevailing culture was biased in favor of wings and that government was determined to kill S1c anyway (or not to revive it).

Well there WAS no support for continued lunar missions in the government for sure and in fact there was a good amount of opposition/bitterness over what some took as insulting failures by NASA and what they considered an out-of-control agency, and as the biggest, most obvious symbol of all that NASA stood for the Saturn-V MOON ROCKET (and that's what it was considered first and foremost in everyone's mind) it was the most obvious target.

But in general the reason wings and glide-back came up so much was it's simplicity and usefulness over recovery at sea and all the effort and costs that entailed.

Look at the situation:
Once its staged, your booster is going around Mach-6+ in the wrong direction from the launch site. Boost back require extra propellant, (technically so does adding mass of wings, wheels and jet engines but that actually works out as somewhat of an advantage because you know have someplace to store all that extra mass and your stage STILL ends up in the same place at around the same speed) with a set of wings you reenter and then do an aerodynamic turn (that costs you no propellant) to guide the stage back towards the launch site.

Of course in most cases it was found that you would not be able to "glide" all the way back to the launch site due to the speeds involved, (the "turn" in most cases had to be performed at low-supersonic or subsonic speed which means you have very little "energy" left at that point to return to the launch site with) which meant having to carry and use ordinary jet engines to actually propel the recoverable stage back to the landing site and the fuel to run them. The engines and fuel will mass far less than the boost-back and landing propellant would due to the very high ISP of such systems.

Once you add in the landing gear and other "landing" systems and structure required the "choice" is a lot less obvious of course, but you have a point in that there WAS a heavy bias towards winged, gliding return as an "obvious" choice. There still is, and its quite understandable as THE primary example of "routine, reusable, transportation" continues to be confused with what rockets do and that's the airplane

And the S-1C is a HUGE stage to be doing a vertical, propulsive landing with. These were folks (and times) when landing the LEM was considered a challenge, now try and wrap your mind around doing the same thing, on Earth, with something that is 421m tall, 10m in diameter and has an empty mass of a couple of hundred metric tonnes...

It was logical that it was possible and probably 'do-able" after all several people at the time were proposing similar systems doing propulsive VTOL (ROMBUS, SERV, SpaceLiner, etc) but...

Wings and wheels seemed MORE logical though, safer, more conservative. More importantly it was probably the only design that could logically get funding under the circumstances...

Randy

[RanulfC]

S1C proposal recovery down-range water landing brochure:
http://www.collectspace.com/ubb/Forum29/HTML/000880.html

I really like that idea. If it were combined with a few small solid landing rockets triggered by a radar altimeter (to keep the F-1s from getting too beat up when hitting the water), that is probably the plausible scheme I've seen for a reusable S-IC.

So far as I've seen this concept was the ONLY one that kept the engines from hitting the water first, and the dual use of the LOX tank as a pneumatic piston is sheer genius to me I just wish it had been applied to a booster with more potential to be continued in service which I don't see the Saturn-V as being

On the other hand though the pushing the very idea of building the S-1C into a reusable booster would have been a better option than going straight to the Shuttle but the idea of "incremental-ism" wasn't getting much traction at that time from what I could tell

A recoverable/reusable S-1C would have given experience and hard economic information for the further development of reusable upper stages (such as SpaceX has been doing) but with a much bigger payload margin to play with it would be more likely to evolve into a fully reusable vehicles I'd think.

Fly-back S1C topped with an workable SASSTO stage for example, based on the SII instead of the SIVB (and probably incorporating the SIVB tankage in fact) as a TSTO launcher. Even just using the afore mentioned recoverable/reusable sea-recovered stage would work as the "RSRM" of the Shuttle should prove

Now I have to start sketching recoverable SII stages "stretched" by adding the SIVB as a "continuing" Apollo program concept

Randy