LOST... Old concepts to project never going off paper

[tater]

2 hours ago, DerekL1963 said:

We'd finally be able to sort out the ones that just might work with some development from the batstuff insane ones for starters...  Some of the stuff they were suggesting in the 60's, well they didn't have the information.

Yeah, I'd love to see someone take another crack at a decent shuttle concept a flyback booster, smaller orbital crew shuttle. This is why Virgin and Stratolaunch are interesting to me, but they really need the broader vision that Musk has (say what you like about it, he's doing it for a reason (that might be goofy), but it's a real goal. Virgin's goal should have been the a cool concept shuttle using HTHL. Hugely risky, though (money wise).

The super heavy concepts (ROMBUS, Boeing LEO, etc) are expensive, so you need an outfit willing to spend the money.

 

[kerbiloid]

They are expensive but they allow to deliver thick and heavy things to orbit, so place many cheap Arduino-class components in the large and thick orbital cystern, protected from vacuum and radiation with its hull.

So, to replace quality with quantity, and to make the space much closer to every junk store mom's engineer casual customer.

***

The Space Shuttle developers aren't guilty that the KH-11 manufacturers happened to be overqualified and left the shuttle without its main job, to rotate them once per year or two.

Edited September 13, 2020 by kerbiloid

[DerekL1963]

1 hour ago, tater said:

The super heavy concepts (ROMBUS, Boeing LEO, etc) are expensive, so you need an outfit willing to spend the money.

You need to have customers willing to buying the services, then you'll have outfits willing to spend the money start popping up.  That's the chicken-and-egg problem that's been holding back development for decades.  You can't get customers without the capability, but you can't get capability without customers.

[tater]

Just now, DerekL1963 said:

You need to have customers willing to buying the services, then you'll have outfits willing to spend the money start popping up.  That's the chicken-and-egg problem that's been holding back development for decades.  You can't get customers without the capability, but you can't get capability without customers.

Unless you have someone with boatloads of money who wants to be their own customer, yeah.

At some point someone has to take the risk. Full reuse is worth the risk, however, because if someone (anyone) manages operational reuse (aircraft-like operations, might be some refurb, but a tiny fraction of vehicle cost), then access becomes orders of magnitude cheaper. The benefit of functional SS (from a LEO business standpoint) is that if it actually works, it's cheaper than expendable vehicles by a lot.

[Guest]

20 hours ago, DerekL1963 said:

0.o  The DC-X/DC-Y/Delta Clipper series of experimental vehicles were designed to prove exactly that - that a booster could be landed vertically.

...and they never did. They got canned before they got anywhere near a booster-sized vehicle, and DC-X, while it worked, was rather small. Also, this project was never about landing a booster. It was about landing a full-fledged, glide-capable SSTO. People thought it was a long shot, and rightly so. 

Ultimately, besides the funding issues, this was another major problem with Delta Clipper, it tried too many things at once. Musk introduced 1st stage reuse with Falcon 9, which, other than that, was an entirely conventional rocket. In a way, that was the breakthrough. Delta Clipper was actually more akin to Starship, an SSTO with extensive aerodynamic controls that would reenter horizontally and land vertically. Only that one was LH2-powered, adding another layer of complexity. In fact, what Space-X started with was far less ambitious, and that's a big part of why it succeeded. 

[wumpus]

19 hours ago, Dragon01 said:

...and they never did. They got canned before they got anywhere near a booster-sized vehicle, and DC-X, while it worked, was rather small. Also, this project was never about landing a booster. It was about landing a full-fledged, glide-capable SSTO. People thought it was a long shot, and rightly so. 

Ultimately, besides the funding issues, this was another major problem with Delta Clipper, it tried too many things at once. Musk introduced 1st stage reuse with Falcon 9, which, other than that, was an entirely conventional rocket. In a way, that was the breakthrough. Delta Clipper was actually more akin to Starship, an SSTO with extensive aerodynamic controls that would reenter horizontally and land vertically. Only that one was LH2-powered, adding another layer of complexity. In fact, what Space-X started with was far less ambitious, and that's a big part of why it succeeded. 

There's a shocking amount of funding that NASA gives to SSTOs (anything non-zero should be shocking, but this was a pretty significant project).

One thing to note: like "NASA doesn't build rockets, contractors do".  NASA doesn't hire employees (there are exceptions), they hire contractors.  I also have wonder just who NASA employees are, and what their backgrounds are.  I'd have to assume that anybody connected to the Apollo hiring wave has long since retired (and probably dead).  I'd guess that anybody around when they were designing/building the first shuttles is retired/retiring.  It won't be too long until they run out of employees who joined up with NASA and are down to pure apparachniks (the contractors do all the real work).  My guess is that this is why SSTO projects still get funding.

Rumor has it that DC-X was cheap to launch, but that might just have been thanks to size.  I've often said that once Space-x gets rocket building costs under control (they've done an amazing job at that), that cutting launch costs will be the next big thing and that Blue Origin (which started out with a lot of DC-X alumni) would have a leg up.

[Guest]

1 hour ago, wumpus said:

There's a shocking amount of funding that NASA gives to SSTOs (anything non-zero should be shocking, but this was a pretty significant project).

Honestly, given what another thread on this board is about, NASA giving money to SSTOs is perfectly reasonable in comparison. Those, at least, have a chance of working out, and are not forbidden by physics, just hard to get right. In fact, Space-X is working on an enlarged, methane-fueled ghost of the full-size Delta Clipper right now. DC-X, BTW, was essentially the Grasshoper of the project, a deliberately simple test vehicle used to try the basic idea without crashing anything too expensive. 

DC-X was cheap to "launch" because it was small and didn't go very far. It didn't so much launch as just flew around. LLTV was also cheap to fly. Fuel and oxidizer costs are not a very significant part of a launch operation. It was repairing it that was too costly.

Edited September 14, 2020 by Guest

[wumpus]

1 hour ago, Dragon01 said:

Honestly, given what another thread on this board is about, NASA giving money to SSTOs is perfectly reasonable in comparison. Those, at least, have a chance of working out, and are not forbidden by physics, just hard to get right. In fact, Space-X is working on an enlarged, methane-fueled ghost of the full-size Delta Clipper right now. DC-X, BTW, was essentially the Grasshoper of the project, a deliberately simple test vehicle used to try the basic idea without crashing anything too expensive. 

DC-X was cheap to "launch" because it was small and didn't go very far. It didn't so much launch as just flew around. LLTV was also cheap to fly. Fuel and oxidizer costs are not a very significant part of a launch operation. It was repairing it that was too costly.

SSTOs based on hydrolox while physically possible have a lousy mass fraction and a huge problem getting enough thrust out of the hydrolox engines.  Reusable SSTOs would have to use something other than hydrolox (air breathers, ground-based power, who knows) because the mass fraction of a chemical based rocket simply doesn't have enough mass for the hardware needed to survive de-orbiting and landing.  Sure, it is better than a device that ignores the conservation of momentum, but that doesn't mean you can build a snowball that can survive being tossed in the Sun or a reusable SSTO that relies on hydrolox.

I'm mostly irked that X-43 lost further funding.  That at least got off paper and up to mach 9.6.  Granted, that tech won't be particularly useful for decades (it will be a long time before fuel consumption has an effect on the cost of a rocket), but getting an air-breather to take you above even to 2000m/s would significantly change the floor of the cost to get things into orbit.

So include the X-43D and beyond on this list (I think the X-43A through X-43C were all launched).

I also like "beamed power" for SSTOs, but that really belongs on powerpoint for even longer than hypersonic airbreathers.  Of course it is quite possible that military lasers might be beaten into ploughshears (presumably after becoming an open secret) to make this happen (who else would develop the lasers/masers?

1 hour ago, Dragon01 said:

 In fact, Space-X is working on an enlarged, methane-fueled ghost of the full-size Delta Clipper right now. DC-X, BTW, was essentially the Grasshoper of the project, a deliberately simple test vehicle used to try the basic idea without crashing anything too expensive.

Starship isn't going to be an SSTO.  There will be Starship (that goes to orbit), and the Super Heavy Booster that gets them the first 3km/s-9km/s of the way there.  Granted, *both* will look like the Delta Clipper, and I suspect even moreso when combined on the pad, but by not being SSTO the difficulty is quite plausible (there are few doubts that the booster will require significant technological development other than the already designed raptor engines and Falcon 9's proven landing capabilities).  Getting Starship to survive orbital descent and having humans on board a vertical landing** are one of the reasons they are building so many prototypes.

And no, neither one will be a reusable SSTO on its own.  Starship will only have the sea-level thrust to land when empty*.  Super Heavy Booster won't be able to survive de-orbiting (even it if can SSTO on its own).  If de-orbiting was that easy, I'd have expected Starship to have orbited already.

* main engines are for vacuum.  Although I might be wrong if they use them as a launch abort system.  I'd still expect it to get out of there and simply burn up the fuel before an aborted landing

** I'm pretty sure even Elon knows that NASA won't let him to this until 2030 at least.

Edited September 14, 2020 by wumpus
missed the bit about "ghost"

[Guest]

27 minutes ago, wumpus said:

Reusable SSTOs would have to use something other than hydrolox (air breathers, ground-based power, who knows) 

Methalox.  Well, I have my own doubts about Starship doing as well as Musk seems to want it to, but it should be able to get a few people to orbit and back, at least. TBH, problems with a hydrolox SSTO seem to be related not to performance constraints, but to difficulties in working with LH2. X-33 was a good idea, but they couldn't get the tanks to work, for instance. It also makes the vehicles using it balloon to enormous sizes, which adds to cost and engineering difficulties. In general, LH2 is far more trouble than its performance figures would indicate, because not only is it ridiculously cold, it makes various materials brittle when it comes in contact with them. Making a hydrolox rocket is hard, which is why companies are now moving away from them. 

Even a nuclear SSTO, which is something I think should have happened already, would be better off using either a dual-propellant engine, something like the LANTR, or even methane, because LH2 is just so bulky. In fact, despite lower (but still in 400-600 range) Isp, methane is a good choice for an all-purpose nuclear propellant. LH2 exceeds where volume is not a problem (such as in Centaur, or deep space nuclear rockets), and on an SSTO, it very much is, due to thermal protection requirements.

X-43 didn't get to mach 9.6 on airbreathing engines. It stayed there, briefly, but it was boosted up to that speed by a Pegasus rocket.

[tater]

1 hour ago, Dragon01 said:

Honestly, given what another thread on this board is about, NASA giving money to SSTOs is perfectly reasonable in comparison. Those, at least, have a chance of working out, and are not forbidden by physics, just hard to get right. In fact, Space-X is working on an enlarged, methane-fueled ghost of the full-size Delta Clipper right now. DC-X, BTW, was essentially the Grasshoper of the project, a deliberately simple test vehicle used to try the basic idea without crashing anything too expensive. 

SSTOs are less likely than TSTO, and substantially harder with any meaningful payload.

Starship is a much better idea, honestly. The Bono designs used drop tanks, after all, and untested plug engine concepts. I've yet to see good data on Delta Clipper (a friend who attended a DC-X flight is trying to get be a copy of a paper on it for me).

The better Shuttle designs were VTHL. Starship could easily be rdone as a HL vehicle like some of the early Shuttle concepts (pop out wings, landing gear). The reason it isn't is Mars. I'm not a Mars fan, but that's why SS is a VL, not HL vehicle. Bottom line is that if you can solve second stage EDL, how you land is just a choice. Surviving can already be done (capsules, Shuttle, etc), the trick is low cost turn around (never done by anyone yet).

 

[magnemoe]

4 hours ago, wumpus said:

SSTOs based on hydrolox while physically possible have a lousy mass fraction and a huge problem getting enough thrust out of the hydrolox engines.  Reusable SSTOs would have to use something other than hydrolox (air breathers, ground-based power, who knows) because the mass fraction of a chemical based rocket simply doesn't have enough mass for the hardware needed to survive de-orbiting and landing.  Sure, it is better than a device that ignores the conservation of momentum, but that doesn't mean you can build a snowball that can survive being tossed in the Sun or a reusable SSTO that relies on hydrolox.

I'm mostly irked that X-43 lost further funding.  That at least got off paper and up to mach 9.6.  Granted, that tech won't be particularly useful for decades (it will be a long time before fuel consumption has an effect on the cost of a rocket), but getting an air-breather to take you above even to 2000m/s would significantly change the floor of the cost to get things into orbit.

So include the X-43D and beyond on this list (I think the X-43A through X-43C were all launched).

I also like "beamed power" for SSTOs, but that really belongs on powerpoint for even longer than hypersonic airbreathers.  Of course it is quite possible that military lasers might be beaten into ploughshears (presumably after becoming an open secret) to make this happen (who else would develop the lasers/masers?

Starship isn't going to be an SSTO.  There will be Starship (that goes to orbit), and the Super Heavy Booster that gets them the first 3km/s-9km/s of the way there.  Granted, *both* will look like the Delta Clipper, and I suspect even moreso when combined on the pad, but by not being SSTO the difficulty is quite plausible (there are few doubts that the booster will require significant technological development other than the already designed raptor engines and Falcon 9's proven landing capabilities).  Getting Starship to survive orbital descent and having humans on board a vertical landing** are one of the reasons they are building so many prototypes.

And no, neither one will be a reusable SSTO on its own.  Starship will only have the sea-level thrust to land when empty*.  Super Heavy Booster won't be able to survive de-orbiting (even it if can SSTO on its own).  If de-orbiting was that easy, I'd have expected Starship to have orbited already.

* main engines are for vacuum.  Although I might be wrong if they use them as a launch abort system.  I'd still expect it to get out of there and simply burn up the fuel before an aborted landing

** I'm pretty sure even Elon knows that NASA won't let him to this until 2030 at least.

Agree totally fully reusable 2 stage rockets beat SSTO with current fuels. Yes you might get it to work with air breathing engines but think even this will be niche. 
External powered might well work it has the benefit of not needing reaction mass before close to hypersonic and then nuclear thermal level ISP without the problem with carrying an nuclear reactor. 
Yes you need expensive ground equipment, down the line space one too and are limited to launch trajectories to set of beaming stations. 

[Guest]

I'm honestly disappointed no one liked the Energia project

[StrandedonEarth]

1 hour ago, The Doodling Astronaut said:

I'm honestly disappointed no one liked the Energia project

Looked like a decent SHLV to me, although it could be improved with vertical integration instead of side-slung payloads. But since the Soviets couldn't afford to, uh, do anything new, they would have been unlikely to build a proper VAB for it.

Besides, it wasn't reusable.

[Guest]

Project Orion:

It's already a famous concept. But I wanted to go deeper

There is a great Wikipedia article on it:

https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

Equation for maximum specific impulse

It was designed to launch off a Saturn V

 

Design of the pressure plate:

The pulse unit:

Problems with Orion:

• ablation with the plate. Fixed with some protection
• fallout from a launch from earth. Debated still to today
• damages to computers and satellites from nuclear explosions (click here to know why)

Why it died:

At the time, there was no real purpose for why you would need such a big capacity. In 1963 a ban treaty was signed that would violate the program.

Will it return:

NASA has a proposed concept but no real return mission planned

But I mean I guess we will get to play with them in KSP 2...

[StrandedonEarth]

20 minutes ago, The Doodling Astronaut said:

Project Orion:

It's already a famous concept. But I wanted to go deeper

Niven/Pournelle ran with the Orion concept in the novel Footfall

[wumpus]

20 hours ago, tater said:

The better Shuttle designs were VTHL. Starship could easily be rdone as a HL vehicle like some of the early Shuttle concepts (pop out wings, landing gear). The reason it isn't is Mars. I'm not a Mars fan, but that's why SS is a VL, not HL vehicle. Bottom line is that if you can solve second stage EDL, how you land is just a choice. Surviving can already be done (capsules, Shuttle, etc), the trick is low cost turn around (never done by anyone yet).

The problem with HL is that those wings are heavy.  The Shuttle had 3 kg of orbiter mass for every 1kg of cargo.  While I don't think the Starship/payload ratio is a key driver is Starship design, I still think they will do significantly better.  HL does have a huge safety advantage (which is odd, because the shuttle had the glide ratio of a brick), so we still might see it again.

14 hours ago, StrandedonEarth said:

Niven/Pournelle ran with the Orion concept in the novel Footfall

Poul Anderson published "Orion shall Rise" two years earlier.  It was a post-apocalyptic work, so his Orion was more as minimalist as possible and still reach anywhere in the Solar System.  Slapping shuttles on Orion makes a good image, but has anybody figured out what it takes to get a RS-25 to restart, or was it a strictly one-way flight (the Footfall Orion was a warship during an alien invasion of Earth).

[tater]

5 minutes ago, wumpus said:

The problem with HL is that those wings are heavy.  The Shuttle had 3 kg of orbiter mass for every 1kg of cargo.  While I don't think the Starship/payload ratio is a key driver is Starship design, I still think they will do significantly better.  HL does have a huge safety advantage (which is odd, because the shuttle had the glide ratio of a brick), so we still might see it again.

If huge crossrange is not throw into the mix (USAF), then Shuttle gets smaller wings. Look at the concept designs vs actual. Some have the wings inside the TPS, they pop out after reentry.

[wumpus]

21 minutes ago, tater said:

If huge crossrange is not throw into the mix (USAF), then Shuttle gets smaller wings. Look at the concept designs vs actual. Some have the wings inside the TPS, they pop out after reentry.

The shuttle had a 1:1 glide ratio.  How much lower do you plan on going?  How fast do you have to land?

[tater]

1 minute ago, wumpus said:

The shuttle had a 1:1 glide ratio.  How much lower do you plan on going?  How fast do you have to land?

 

 

Not all were like this, many had pretty large wings.

 

[DerekL1963]

56 minutes ago, tater said:

If huge crossrange is not throw into the mix (USAF), then Shuttle gets smaller wings.

The question is:  How small, really?  Reading Jenkins, crossrange (or the lack thereof) was already becoming a problem even before the USAF was dragged onboard.

Even without the USAF's high crossrange requirements, crossrange is Really, Really Useful in routine operations.  Crossrange allows a wider range of abort options and widens landing windows/creates landing opportunities (as compared to less or no crossrange).  Increasing crossrange trades weight for safety and operational flexibility.  (And it should go without saying that all real world designs are the product of endless trade-offs and compromises.)
 

1 hour ago, tater said:

Look at the concept designs vs actual.

I've said it before, but it's worth saying again:  You have to be really careful using concept art to evaluate "what might have been".  There were multiple configurations being examined in parallel, so there's no "one path" of evolution to trace.  Also, some proportion of that art is all but outright fantasy - they needed a Shuttle in the picture, and so they put a Shuttle in the picture...  It may or may not trace back to an actual design study.

[kerbiloid]

Spoiler

 

[tater]

24 minutes ago, DerekL1963 said:

Even without the USAF's high crossrange requirements, crossrange is Really, Really Useful in routine operations.  Crossrange allows a wider range of abort options and widens landing windows/creates landing opportunities (as compared to less or no crossrange).  Increasing crossrange trades weight for safety and operational flexibility.  (And it should go without saying that all real world designs are the product of endless trade-offs and compromises.)

I suppose you'd need an actual abort mode on launch. Shuttle abort modes were pretty much 100% fantasy on liftoff. I suppose if a new one had a real abort mode, then the crossrange might help. The early designs often had a jet engine, however. Aborts on EDL... not sure what would cause such a need to change landing areas, but it's not like the US is short on airports. The wings are really only used at the very end of the mission, hence the folding versions on many designs—the total wing area might actually be not that far off the actual Shuttle. It's a trade off though, as you say. You save mass by not having dead weight strong wings to deal with launch and entry (also adds issues with launch abort modes), but you add a failure mode (wing deploy failure).

I don't pretend to be an expert on Shuttle concepts, but it's worth noting that many looked different than the one that flew, and a smaller Shuttle for just crew is probably more managable (Dream Chaser like but built large enough to encompass a second stage tank and engines? Closer to an X-37 Crew?).

[DerekL1963]

12 minutes ago, tater said:

Aborts on EDL... not sure what would cause such a need to change landing areas, but it's not like the US is short on airports.

I didn't say there were aborts on EDL...

What crossrange does for EDL is increase the number and width of landing opportunities.  With no crossrange, your orbit has to pass more-or-less directly over your landing target...  How often does that happen?  The more crossrange you have, the further your ground track can be from your landing target and still be able to reach your target.  It increases your abort-from-orbit options, but I don't think you can do much about increasing your EDL options by any significant amount.

Yes, the US has plenty of airports.  However, it doesn't have many airports that can be shut down and all traffic diverted on short (<6-8 hour?) notice without massive (and unacceptable) disruption.  And few of those remaining are going to have the capability to recover a shuttle...  Ground support is an issue, as is the ability to support ferrying.  (If you're talking a fantasy beast that needs no more support than a conventional airliner and can self ferry...  We need to be over in the SF thread.)

The jet engines were there to modestly increase cross and along track capabilities.  (I don't believe any but the most far-fetched designs were capable of self ferrying.)
 

22 minutes ago, tater said:

The wings are really only used at the very end of the mission, hence the folding versions on many designs—the total wing area might actually be not that far off the actual Shuttle. It's a trade off though, as you say. You save mass by not having dead weight strong wings to deal with launch and entry (also adds issues with launch abort modes), but you add a failure mode (wing deploy failure).

I don't think swing wings will save mass...  You still need 'x' wing area for 'y' capability - and you add in the weight of the hinging mechanism.  And if you want cross range, I suspect they're going to have to deploy prior to entry anyhow.

[tater]

9 minutes ago, DerekL1963 said:

Yes, the US has plenty of airports.  However, it doesn't have many airports that can be shut down and all traffic diverted on short (<6-8 hour?) notice without massive (and unacceptable) disruption.  And few of those remaining are going to have the capability to recover a shuttle...  Ground support is an issue, as is the ability to support ferrying.  (If you're talking a fantasy beast that needs no more support than a conventional airliner and can self ferry...  We need to be over in the SF thread.)

Shuttle flew for a long time and literally never used this capability, right? They landed at Edwards (a few times), WSMR (once, I think), and FL. All were planned well in advance (weather at the Cape bad because FL), right?

It's an issue, but not a substantial one that logistics are a concern, it would only ever be used in a dire emergency I assume (else it would have happened already during Shuttle).

EDIT:

54 at Edwards (oops)

1 at WSMR

All the rest in FL.

 

9 minutes ago, DerekL1963 said:

I don't think swing wings will save mass...  You still need 'x' wing area for 'y' capability - and you add in the weight of the hinging mechanism.  And if you want cross range, I suspect they're going to have to deploy prior to entry anyhow.

Might well be true. I'm just trying to see if any of these old ideas still actually make sense, my pref has always been the Bono designs, so...

Edited September 15, 2020 by tater

[DDE]

4 hours ago, wumpus said:

The shuttle had a 1:1 glide ratio.  How much lower do you plan on going?  How fast do you have to land?

There's always another option: