Do you think Skylon will be our first completed SSTO?

[Kerbface]

It sounds like a very promising project, but apparently the UK and ESA can be kind of flakey on projects like this. Would hope to not see it fail, or at least complete the engine design. That's always been the idea with spaceplanes, convenient and saves fuel while in atmosphere by using air breathing engines, so I think having them convert to rocket engines partway through is great.

[lyndonguitar]

I think not, more like the Sabre engine will be our first completed SSTO Engine

[GJames]

The Skylon uses SABRE engines to fly, so I reckon it could be. It is by far the most promising that I've heard of, and it could be doing test flights in just over 5 years time...

[tek_604]

I'd like to know where the 5 year estimate came from! They only just started a 3 1/2 year program to build a test jig to make sure the engine will work fully. The engine itself has never been fully tested. They've still got to design & build & test the airframe. All this takes money & time.

I want this to work I really do. It'll be the best thing to come out of Britain's engineers since... well, whatever. But, if only we can make it fly. Thats the question.

[Nibb31]

They've been working on it for 30 years, and they have virtually no budget. They are basically just a bunch of BAe retirees with a dream and some cool Powerpoint presentations.

In all this time, all they have accomplished is some theoretical studies and a couple of lab proofs-of-concept for minor parts of the SABRE engine. They are a very long way from having an actual prototype engine, a longer way from having a reliable operational production engine, and a mindbogglingly long way from having a low-maintenance reusable spacecraft.

So no, without a major investor stepping in, there is no way such a small team can design and build a reusable launch infrastructure from scratch, where organizations like NASA, Boeing, Lockheed Martin and others, have spent billions and failed.

[Kryten]

If you just want 'first SSTO', ARCA plan to do it with their first orbital flight, within a couple of years...

[tek_604]

So no, without a major investor stepping in, there is no way such a small team can design and build a reusable launch infrastructure from scratch, where organizations like NASA, Boeing, Lockheed Martin and others, have spent billions and failed.

And thats where, in principal anyway, where ESA could step in, and have done, to provide the investment. So far, the investment will not get them to fly, but, should at least be able to get the engine working. Then comes the airframe. But, I would guess they're at least 10 years off having the engine ready.

Even NASA failed with similar projects, and ended up handing them over to DARPA. Europe doesn't have a DARPA. By the time Skylon is finished, it will be a distant 2nd to the American effort (X-51). But, thats not to say Europe shouldn't at least try.

[GJames]

I'd like to know where the 5 year estimate came from! They only just started a 3 1/2 year program to build a test jig to make sure the engine will work fully. The engine itself has never been fully tested. They've still got to design & build & test the airframe. All this takes money & time.

I want this to work I really do. It'll be the best thing to come out of Britain's engineers since... well, whatever. But, if only we can make it fly. Thats the question.

They stated in 2011 that they could have a suborbital test flight by 2016. Bit optimistic, I know, so emphasis on the "could" part. ESA and the UK Space Agency conducted a review of the project and found that: ‘no impediments or critical items have been identified for either the SKYLON vehicle or the SABRE engine that are a block to further developments’.

Obviously there will be delays and setbacks, as is the nature of new technologies. But this does look really good, and I'll be following it with interest...

EDIT: The X-51 that the US is developing probably won't be used for anything like an SSTO. Instead they're planning on turning it into some kind of high speed strike weapon...

Edited June 6, 2013 by GJames

[Nibb31]

If you just want 'first SSTO', ARCA plan to do it with their first orbital flight, within a couple of years...

The Titan II first stage from 50 years ago was capable of SSTO if you cared to launch it with zero payload, which would have been useless. SSTO itself is pointless, but actually easy. It's SSTO with a significant payload that is difficult to achieve, as well as reusability. SSTO for the sake of SSTO doesn't make sense.

SSTO, reusability, and low-cost are 3 different things. Generally, the goal is to reduce the cost to orbit, which is not necessarily related to achieving SSTO or reusability. SSTO and reusability are engineering parameters, but cost is usually a function of the market environment and many complex parameters, of which engineering is only a minor factor.

Even NASA failed with similar projects, and ended up handing them over to DARPA. Europe doesn't have a DARPA. By the time Skylon is finished, it will be a distant 2nd to the American effort (X-51). But, thats not to say Europe shouldn't at least try.

X-51 has nothing to do with SSTO or spaceplanes.

Edited June 6, 2013 by Nibb31

[tavert]

I believe that review was entirely technical, with some estimate of the financial investment required but no discussion of where that several billion dollars would come from. They've been testing the precooler heat exchanger technology, which is probably their biggest single breakthrough in terms of performance relative to existing designs. But the whole helium cycle machinery that they need to build next is godawfully complex and unproven. They've done the conceptual design and preliminary sizing, performance analysis, etc that says it should theoretically work. But as far as detailed component-level and system-engineering design, whether it's controllable, if they have any hope of meeting weight targets, etc it doesn't look like they've had enough resources to get very far. They essentially have to design and build a type of power plant that no one has ever made before.

It's quite a bit more complex and unlike existing turbopump rocket engine cycles. Some of the components are common and the same engineering principles apply, but the system design is unique.

Edited June 6, 2013 by tavert

[tek_604]

X-51 has nothing to do with SSTO or spaceplanes.

Maybe not quite in the way of Skylon or HOTOL, but with regards hypersonic flight and getting an engine to take air in without everything melting, it is. And thats cost DARPA billions, and still doesn't work quite right. Sure, it won't be a spaceplane, but, think about it; its trying to get to similar speeds required for orbital insertion, just on a smaller scale. Now scale those problems up...

I think we're all agreed, without substantial amounts of money being pumped in, and I'm talking orders of magnitude more than they have now, Skylon, if it ever makes it, is 20 or 30 or more years away. With DARPA amounts of funding (and that will never happen in Europe), it could be done in 10.

[GJames]

Definitely needs more funding, but hopefully if they prove that the technology is feasible they'll attract some serious attention from private companies, governments and ESA. It could happen, and I hope it does.

[White Rider]

I always laugh when people discredit low buget British engineering projects simply because companies like NASA and others have failed on similar projects.

British engineers have been building amazing things in SHEDS for years.

If Reaction Engines get the funding they need, I'm sure they will go far.

[Thaniel]

Remember the 19th of september, remember Otrag.

While Skylon have been worked on for decades now, and they have a sound idea and concept, there are many companies today that are scared ****less if they actualy manage to do what they try to do.

A reusable SSTO airplane able to lift off from an ordinary runway and enter orbit, carrying a usefull payload.

While a wet dream for anyone involved in spacerelated science and exploration, it's a nightmare for anyone living of launching sattelites. I just hope brittish ingenuity prevails with the ESA funding, and they manage to show a working prototype. Even that's no guarantee, people love to deny the existence of working prototypes as well.

Edited June 6, 2013 by Thaniel

[White Rider]

How much are the ESA funding them for?

The engine is done and tested. That's what's been holding them back. Now that's done £££ is the only issue.

[Kryten]

The engine is done and tested.

A small part of the engine has undergone a few tests. They're still a long way from proving the plan is technically feasible, and a lot further from showing it to be economically feasible.

[Person012345]

They've been working on it for 30 years, and they have virtually no budget. They are basically just a bunch of BAe retirees with a dream and some cool Powerpoint presentations.

In all this time, all they have accomplished is some theoretical studies and a couple of lab proofs-of-concept for minor parts of the SABRE engine. They are a very long way from having an actual prototype engine, a longer way from having a reliable operational production engine, and a mindbogglingly long way from having a low-maintenance reusable spacecraft.

So no, without a major investor stepping in, there is no way such a small team can design and build a reusable launch infrastructure from scratch, where organizations like NASA, Boeing, Lockheed Martin and others, have spent billions and failed.

Bah, men in sheds is how we make all the greatest discoveries.

[White Rider]

Sheds FTW.

The ESA seem happy enough with the tests that HAVE been done. I can only guess that given that (within their market) everyone and their grandad knows how to build a rocket engine that that "part" of the engine that needed testing approval and was tested would be the important (and revolutionary) one... The precooler.

[Fuzzy Dunlop]

They've been working on it for 30 years, and they have virtually no budget. They are basically just a bunch of BAe retirees with a dream and some cool Powerpoint presentations.

In all this time, all they have accomplished is some theoretical studies and a couple of lab proofs-of-concept for minor parts of the SABRE engine. They are a very long way from having an actual prototype engine, a longer way from having a reliable operational production engine, and a mindbogglingly long way from having a low-maintenance reusable spacecraft.

So no, without a major investor stepping in, there is no way such a small team can design and build a reusable launch infrastructure from scratch, where organizations like NASA, Boeing, Lockheed Martin and others, have spent billions and failed.

More than a little harsh, what they have done is build and successfully test what is by most measures the highest performing heat exchanger ever designed.

Reusable SSTO's are basically physically impossible, we can't push engine ISP much higher (a least not with feasable chemical propellents) and current materials science wont allow us to push the fuel fraction of tanks much higher. Plug this into the rocket equation and your payload is only just enough to cover your heat shield. So either you need voodoo chemistry or voodoo super-strong materials.

Or you cheat the rocket equation and gather some of your propellent in flight. Problem is the only way to do this is to scoop up air at mach 5, and it's hard to burn it at that speed. This is what a scramjet is, unfortunatly their thrust to weight ratio is so aweful that they'll end up eating all your payload fraction and then some.

Or you could slow the air down and then burn it, like normal jets and ramjets do. Thing is, this makes the air hot, and when you're slowing it down from mach 5 it makes it too hot to burn effeciently (also it might melt everything).

Could you cool it down? Well yeah you could, in fact given how much cryogenic liquid hydrogen you've got on tap you could easily chill down enough air. Only snag is that you'd need a cooler so big that you couldn't carry anything else to orbit, also it would probably chill all the water out of the air and freeze over. Unless you have some fancy voodoo heat exchanger that is... wait you do?

The point about Skylon is that it is the only proposal for a reusable SSTO that doesn't depend upon a single piece of technology that has never been tested before. Yeah, there are so many ways it could fail; the SABRE engines are unique and horrificallycomplex, SKYLON itself is a huge aircraft that can't afford to be even a couple of tonnes overweight. It will stuggle to get the funding it needs and even then there's no guarantee it will ever fly - But at least we know that it can work. We're not even certain any other proposal is physically possible.

[Rune]

Maybe not quite in the way of Skylon or HOTOL, but with regards hypersonic flight and getting an engine to take air in without everything melting, it is. And thats cost DARPA billions, and still doesn't work quite right. Sure, it won't be a spaceplane, but, think about it; its trying to get to similar speeds required for orbital insertion, just on a smaller scale. Now scale those problems up...

I think we're all agreed, without substantial amounts of money being pumped in, and I'm talking orders of magnitude more than they have now, Skylon, if it ever makes it, is 20 or 30 or more years away. With DARPA amounts of funding (and that will never happen in Europe), it could be done in 10.

A Scramjet is the worst possible kind on engine for a SSTO. It's heavy, it needs another engine to get to start up speed (and that's hypersonic start up speed), and the whole airframe must be designed around it. As you have already been told, the X-51 has nothing to do with spaceplanes, and everything to do with hypersonic cruise missiles that can't be confused with ICBMs.

As to Skylon, it is indeed the most workable SSTO concept I have seen to date, if the preliminary testing keeps on being as successful as it seems it has been to date. However, I just can't see anybody funding it at the level required (A-380 funding level, remember). Until someone does, it will remain a very interesting paper concept, and no amount of work in a shed is going to get over that. To get Skylon to fly, you need a Boeing/Airbus/similar aerospace giant seriously committed, probably with ample government support. I just don't see that kind of interest in space from the people with the really big pockets.

Rune. No bucks, no Buck Rogers. And we are talking about ~20 billion of them.

[White Rider]

what they have done is build and successfully test what is by most measures the highest performing heat exchanger ever designed.

-snip-

Coupled with the probability that the original concep was probably designed in a shed the idea is pretty fantastic.

Ok, ok enough with the sheds...

They do have the issue that the SKYLON plane itself, frame and all is yet to be tested at all.

It could fail spectacularly. But when they have done what they have done with the engine engineering wise, what really is the likelyhood that they screw that part up?

And even if they do and the frame they originally designed sucks... That engine man...

It's destined for big things.

[White Rider]

To get Skylon to fly, you need a Boeing/Airbus/similar aerospace giant seriously committed, probably with ample government support. I just don't see that kind of interest in space from the people with the really big pockets.

I wouldn't be surprised if Branson ponied up the cash. He's done stranger things.

The quoted figure is reportedly around £380m. Not in the billions like DARPAs projects. They already have the hardest part (effectively) done.

That figure is obviously BS, and will no doubt rise significantly but still a drop in the water compared to other projects with as much substace as edible paper.

[Rune]

I wouldn't be surprised if Branson ponied up the cash. He's done stranger things.

The quoted figure is reportedly around £380m. Not in the billions like DARPAs projects. They already have the hardest part (effectively) done.

That figure is obviously BS, and will no doubt rise significantly but still a drop in the water compared to other projects with as much substace as edible paper.

The last figure I heard quote an actual member of Reaction Engines Ltd. was 19 billion euros for the whole development programme. If you have some other source, I'd like to see it. It also makes sense, that a big airplane-like thingy will cost about the same as another big plane.

Rune. Actually, any recent news would be appreciated.

[White Rider]

Apologies Rune, the £380m figure was from a few months back. I misread.. that was the number they (at the time) needed to really "get the project off the ground." Whatever that meant. The source was BBC.

In 2010 the full project number was apparently somewhere in the region of £12billion so your figure of 19 seems reasonable enough to assume its correct as far as we are likely to be aware.

[Themohawkninja]

Well, I haven't heard of any more promising programs, and Skylon does look very promising, so I think it will be the first.