Reusable spaceflight

[uk 75]

Now that we live in a world where ancient Soyuz capsules and a private venture US version are the only means we have of getting people into orbit, and no humans have left earth orbit since 1973, I was wondering what the alternatives might have been.
Should the US have developed a proper reusable spaceplane/shuttle programme from the 1960s on?
Should the Saturn V/Apollo have been churned out as the basic vehicle for a continuous manned space programme up to the present day like the Russian launchers?
Or should we have stopped all manned spaceflight after the moon landings and spent serious money on unmanned systems?

 

[martinbayer]

True reusability is key to bring costs down and open up space access. SpaceX is exhibit #1. Terrestrial power, resource and environmental concerns may become major drivers for industrial scale space activities over the next decades, such as the creation of space solar power platforms. Space tourism offers potential business opportunities in a fundamentally different sector. But while the exact focus of future space architectures may yet be unclear, and a high level of uncertainty persists with respect to what will be most probable and promising candidates for future space efforts, the aggregate probability of eventual large scale activities is IMHO high, and LEO will be a bridgehead in space. Therefore, although the actual main constituents of future global space activities can not accurately be defined at this time, cost effective, routine, reliable space transportation is an indispensable prerequisite for any and all large scale space endeavors. Reusable space transportation systems appear best suited to reduce transportation costs to levels required for such purposes. The optimum approach for supporting a wide spectrum of space science opportunities as well as enabling a large and robust space based economy sector lies therefore in creating a space transportation infrastructure with broad applicability that represents the common denominator for any and all future space activities, be they commercial, civil or defense related. Space transportation to low Earth orbit is the most basic space related activity that is required across the board for any effort, and the Earth-orbit transfer is a vital gateway that all space architectures have to pass through, even if only to deploy elements that allow to eventually harvest and process extraterrestrial resources. Reusable space transportation architectures are therefore generally seen as a universal enabler for opening space to widespread commercial use. Therefore, the first step towards and foundation for any sustainable space policy must be to develop, implement, and operate space transportation systems that provide essential capabilities for multiple users and applications, including assured access to and from low Earth orbit for passengers and cargo. Post Apollo at the latest, NASA’s focus (with associated backing/funding by Congress) should have changed from a fixation on crewed missions to solving this issue first with a true RLV, since reliable, routine, safe crewed space access will be a natural byproduct of any fully reusable launch vehicle. Only once this first step to orbit is reliably mastered once and for all does it make sense to start contemplating a return to the Moon or going on to Mars, since any space architecture based on expendable launch vehicles will ultimately rest on clay feet. Not that I have any strong feelings on this topic though...

 

[RanulfC]

Now that we live in a world where ancient Soyuz capsules and a private venture US version are the only means we have of getting people into orbit, and no humans have left earth orbit since 1973, I was wondering what the alternatives might have been.
Should the US have developed a proper reusable spaceplane/shuttle programme from the 1960s on?
Should the Saturn V/Apollo have been churned out as the basic vehicle for a continuous manned space programme up to the present day like the Russian launchers?
Or should we have stopped all manned spaceflight after the moon landings and spent serious money on unmanned systems?

IMO the US should have kept developing the Saturn-1B with seperate cargo and passenger/cargo/light-space-station support rather than leaping straight to the Space Shuttle. There were some good "glider" type vehicles in the wings, (see this thread and attached study: https://www.secretprojects.co.uk/threads/convair-variable-geometry-spacecraft.33646/) and the Saturn-1B could have been vastly cheaper with a higher flight rate as well as having numerous options for improvment. Frankly it coud have been turned into a recoverable booster stage and while it's likely the S-IVB would have been made cheaper and less robust I've seen several plausible paths to it also being turned into a recoverable stage at some point.

A similar pathway could lead to a fully reusable, (sans trunk unfortunatly) Falcon 9 but it a path SpaceX is unlikely to tread with the focus on Starship.

Affordable, assured access on a regular schedule it pretty much the key and to get there eveyone has pretty much known all along was going to require reusability to be developed and deployed. Even the Soviets developed what was supposed to be a partially reusable system with Energia, with the boosters recovered down-range by parachute. This was never installed or used and the entire LV was too expensive to operate for long at any rate.

As martinbayer notes NASA had fixated on manned spaceflight being primary which translated down to every flight having to be manned no matter what. Hence the fixation on a fully reusable TSTO from the start with both stages manned and enough capacity to fly large space station parts on every flight. This pushed the size and complexity of the shuttle concept upwards with the results was all know.

Recovery and reuse is a key but in addition there has to be enough of a market and demand to keep flight rates high and justify the recovery and reuse which historically is less clear.

Randy

 

[Dilandu]

Should the US have developed a proper reusable spaceplane/shuttle programme from the 1960s on?

Er... they tried) Space Shuttle, remember? Problem was, that there were little money available, the project was simplified/worsened to make it cheaper, and the whole approach essentially was a bit outside available technology.

Should the Saturn V/Apollo have been churned out as the basic vehicle for a continuous manned space programme up to the present day like the Russian launchers?

I'm afraid, it would be impossible. "Saturn V" was quite a costly rocket - an engineering work of art, but complex and expensive. And "Appolo", frankly, have little further ways to evolve. Oxygen atmosphere was a technological dead end.

 

[RanulfC]

Should the US have developed a proper reusable spaceplane/shuttle programme from the 1960s on?

Er... they tried) Space Shuttle, remember? Problem was, that there were little money available, the project was simplified/worsened to make it cheaper, and the whole approach essentially was a bit outside available technology.

"Smaller" is better Or in aerospace it's at least a bit cheaper to build initially. Problem was it was too big, too much and to far advanced for the time at least in the sense it was supposed to be a fully operational vehicle from the start. It should have been a "shuttle" not the "Shuttle" as a part of rather than the whole of the ongoing program. On the other hand, (and being generous) they were probably right to think that if they didn't get 'everything' right from the begining that Congress would nickle and dime the rest of the effort away and they'd never get any further. It's essentially what Congress did and is doing today.

I personally believe that they could have manged a smaller and more general program if the will have been there but I can also understand how hard that would have been to 'come down' to from Apollo. Still that was pretty much their job was it not?

Should the Saturn V/Apollo have been churned out as the basic vehicle for a continuous manned space programme up to the present day like the Russian launchers?

I'm afraid, it would be impossible. "Saturn V" was quite a costly rocket - an engineering work of art, but complex and expensive. And "Appolo", frankly, have little further ways to evolve. Oxygen atmosphere was a technological dead end.

[/quote]

Yes the Saturn V had one job and that was going to the Moon. Any attempt to keep it around was doomed on a economic basis alone. Apollo on the other hand still had some options but the main question was the cost versus the utlity since (as we've noted) everyone was sure that reusablity was the way to go and that, at the time, essentially meant wings-and-wheels of some kind. The Apollo capsule could be made reusable pretty easily but it was limited to around 5 astronauts in discomfort unless they expanded the outer mold line which was arguably the 'next' step anyway. The propsoed expansions went from 3 to 5 astronauts to 9 to 12 in the basic expansion and upwards of 24 for some of the more "less-plausible" concepts. But essentially it was still a capsule and even if reused not seen as especially economical in the long run.

The problem was that IF they were going to keep any Saturn they of course prefered to keep the Saturn V so the Saturn 1B fell out early and plans to mount Shuttles and Space planes on the S1C began to be the most studided options. And of course as stages in and of themselves, (plus cargo and crew) they tended to be big and expensive even before you figured in design and development costs.

Randy

 

[Dilandu]

The Apollo capsule could be made reusable pretty easily but it was limited to around 5 astronauts in discomfort unless they expanded the outer mold line which was arguably the 'next' step anyway. The propsoed expansions went from 3 to 5 astronauts to 9 to 12 in the basic expansion and upwards of 24 for some of the more "less-plausible" concepts. But essentially it was still a capsule and even if reused not seen as especially economical in the long run.

That was exactly the problem. Souyz became so effective, because it was more general-purpose craft than Apollo. You could modify Souyz for the array of missions just by refitting the orbital habitation module, without the need to rebuild the re-entry capsule. With Apollo, it was impossible. And again, oxygen atmosphere... It was a good short-therm solution, yes, but in long therms the oxygen-atmosphere crafts were just too problematic and dangerous. And I'm not sure, that Apollo could be refitted to use normal atmosphere without essentially building a completely new spacecraft.

 

[RanulfC]

That was exactly the problem. Souyz became so effective, because it was more general-purpose craft than Apollo. You could modify Souyz for the array of missions just by refitting the orbital habitation module, without the need to rebuild the re-entry capsule. With Apollo, it was impossible. And again, oxygen atmosphere... It was a good short-therm solution, yes, but in long therms the oxygen-atmosphere crafts were just too problematic and dangerous. And I'm not sure, that Apollo could be refitted to use normal atmosphere without essentially building a completely new spacecraft.

Apollo DID use a standard nitrogen-oxygen atmosphere after Apollo 1. They just transitioned to almost pure oxygen after lift off because the SUITS were designed to only use pure oxygen as an atmosphere. In fact they still are since they have to use a lower pressure in order to be able to move at all Hence why both Shuttle and ISS astronauts have to spend a couple hours 'pre-breathing' pure o2 to purge the body of nitrogen.

Soyuz was relativly cheap but it maxed out early in capability since you couldnt vary the crew much and while the habitation module gave some flexability it was the reentry module that dictated the mission. Apollo on the other hand was going to always be expensive but inherently more capable. If for no other reason than the enherent lift capability of it's likely launch vehicle. But expanding it from 3/5 to 9/12 was going to pretty much add a ring and new heat shield and a larger, (but squatter) SM about doubling the basic cost of the vehicle, but a pretty well studied and understood extention.

Personally I don't see it and it would likely have remained just a more advanced version of the Block III but adding two more seats and a set of retro-rockets. It would have been 'available' but far to expensive to use on a regular basis. So a new crew vehicle is pretty much a given and if they can avoid the 'requirement' of flying and bringing everything back in a single vehicle, (the Shuttle problem) we'd still see it looking like one of Convair study "winged bodies" because lets face it, that was the thinking at the time.

Randy

 

[Dilandu]

hey just transitioned to almost pure oxygen after lift off because the SUITS were designed to only use pure oxygen as an atmosphere. In fact they still are since they have to use a lower pressure in order to be able to move at all Hence why both Shuttle and ISS astronauts have to spend a couple hours 'pre-breathing' pure o2 to purge the body of nitrogen.

Er, not only that, but also because it allows the capsule to be made lighter - due to lower internal pressure (if I recall correctly).

Apollo on the other hand was going to always be expensive but inherently more capable.

It have more delta-V, but I wouldn't call it " inherently more capable" due to the limited architecture.

 

[uk 75]

Broadening this thread out rather than starting a new one.
The spaceplane (best illustrated in 2001 Space Odyssey) as opposed to the booster and capsule route into space seems to have died a death as too complicated and expensive.
Was this inevitable?

 

[Hobbes]

I don't think so. The Space Shuttle was large and heavy, which meant it was expensive to build and placed high demands on the heat shield. This led to a heat shield design that was expensive and fragile (=high maintenance cost). If Musk's experiments with Starship pan out, that would show cheaper alternatives are possible. IDK what SpaceX use for the heat shield, and if that would have been feasible to design in the 1970s. The underlying stainless-steel structure is old technology. With some adjustments to the airframe shape, it should be possible to rationalize tile shapes (see SpaceX's series production of hexagons vs. Space Shuttle with tens of thousands of unique shapes).
The USA went straight from Apollo to a kitchensink design, under financial constraints that led to non-optimal design decisions.

 

[martinbayer]

Broadening this thread out rather than starting a new one.
The spaceplane (best illustrated in 2001 Space Odyssey) as opposed to the booster and capsule route into space seems to have died a death as too complicated and expensive.
Was this inevitable?

I'd like to get a better understanding of how you exactly define a spaceplane - the Orion 3 is only one of countless conceivable configurations. I assume wings and (full?) reusability are implied, but would you consider both HTHL (with or without takeoff assist/launch aids) and VTHL, SSTO and TSTO (or even 3STO like the Lockheed concept shown at https://www.secretprojects.co.uk/threads/lockheed-california-earth-to-space-shuttle-of-1964.6741/), airbreathing and rocket propulsion (in all variations and amalgamations), and any and all theoretical potential combinations thereof to fall in this category? The answers to your question will notably differ for different concrete concepts in the wide range of permutations.

 

[Archibald]

That's the usual problem with space TLs - too many PODs, too many interesting (but non built) technologies...

For a workable Shuttle, my 100% hindsight favored solution would be

BOOSTER
- expendable S-IC (mass fraction 0.94)
- flyback S-IC (mass fraction 0.85)

ORBITER - tricky. Very tricky.
-IF hydrolox: internal LOX, external tank LH2
-IF something else: same mold as OTL Shuttle Orbiter
-except with the 300 cubic meter payload bay turned into a huge propellant tank. (payload would have to find itself another place to go)
- it would be possible to pile up 300 mt of kerolox inside the orbiter, enough to go in orbit with a small payload... if all goes well.

 

[uk 75]

I was tending to think of the literal version. A planelike vehicle which can go into orbit and recover to a runway afterwards.
But I am always happy to travel as widely as possible for ideas and information. So feel free

 

[Archibald]

Well I picked suborbital refueling as a "pet peeve" just for that reason.

I wanted a "spaceliner": that is, two jet engines like an A320, except with a rocket in the tail to go into orbit.
The rocket burns kerosene, the turbojet also burn kerosene, and kerosene is fine for airports, ground crews.
The rocket need oxidizer and there it is trickier for airports.

The least evil oxidizer is a thing called nytrox. Don't laugh: the inventors seemingly raided an hospital, and stole a) liquid oxygen and b) laughing gas / anesthetic : nitrous oxide or N2O.

Mixing N2O and LOX seemingly provides a begnin rocket oxidizer for airports.
Good then: kerosene and a innocuous oxidizer to burn it.

Problem: that's too heavy. Jets+Rockets can't go into orbit.
Except by cheating !
Blame planet Earth, which is a fatty and very dense, unlike Mars.
End result: takes a Mach 26 (yes, MACH 26) to go in orbit around it.

All right then, here is the plan to cheat the goddam orbit "Mach 26" daunting speed (delta-v for rocket nerds).

-1 Orbiter Turbojets to Mach 3 or Mach 4; then "lit the rocket" in the back.
-2 Orbiter rockets to Mach 20 and suborbital flight
-3 PIT STOP: for four minutes, a twin rocketplane acts like a KC-135, that is: a tanker refueling the orbiter.
-4 Tanker rocketplane glides back to Earth, orbiter makes the final step from Mach 20 to Mach 26 and boom, in orbit with a decent payload of cargo and passengers.
-5 Job done.

I can't see another way for practical "airport to orbit". Not using kerosene and jets, at least - like an A320.

 

[Michel Van]

Er... they tried) Space Shuttle, remember? Problem was, that there were little money available, the project was simplified/worsened to make it cheaper, and the whole approach essentially was a bit outside available technology.

NASA try with hardware of 1960s to build a Space Shuttle that could worked,
Then step USAF in game and Shuttle became BIG !
But sadly they got politic not right and Capitol Hill swing the Budget axe after Apollo,
NASA try to cope with situation by dropping the original hydrolox Design.
and went for Saturn F-1 Flyback with Orbiter,
but Capitol Hill swing the Budget axe again, thanks to Walter Mondale private little war with NASA.
NASA Administrator Fletcher was too inexperienced in time,
He went for cheapest design Big Solids, External tank and Orbiter with High Pressure engines.
This was cheapest Design to build, but also the one with Highest flight and maintenance cost.
Next to had Rockwell complete underestimated the issues with orbiter heat-shield maintenance.

The Shuttles flow around 135 times, lost two orbiters and launches cost the same as a Saturn V.
Do large maintenance workforce that cost allot of money, while Capitol Hill underfunding NASA...

But in 2002 came new Company called SpaceX, It's boss had other radical ideas on Reuse of Rockets.
and 22 December 2015 Space X made history by returning a rocket to launch site and land nearby...

 

[martinbayer]

I was tending to think of the literal version. A planelike vehicle which can go into orbit and recover to a runway afterwards.
But I am always happy to travel as widely as possible for ideas and information. So feel free

To me, at one extreme end of the spectrum is an HTHL SSTO airbreathing/rocket propelled RLV like NASP or Skylon, and I don't expect to see anything like that fly in my lifetime, if ever. On the other hand, I firmly believe that a liquid rocket propelled VTHL TSTO/3STO with similar or even largely identical parallel staged stages based on a wing/body concept with cylindrical fuselages, using propellant crossfeed with the simultaneous ignition of all main engines at liftoff, and incorporating state of the art technologies, including many of Musk's innovations e.g. w.r.t. TPS, would be feasible today, if there were the sustained determination/funding for it. The DARPA/Boeing XS-1/XSP (a.k.a. Experimental Spaceplane) reusable winged booster came agonizingly close to being a first stage pathfinder for such a concept before the plug was pulled.

 

[publiusr]

If I were Bezos, I’d write you a big check and walk away.