Skylon

[smujsmith]

I'm possibly a bit behind the curve here but just seen a story in the Times, announcing that "el taxpayer" in the form of the Government is awarding a £60 million grant for the Reaction Engines Skylon project;

Reaction Engines Ltd - Space Access: SKYLON (http://www.reactionengines.co.uk/space_skylon.html)

http://i1292.photobucket.com/albums/b572/smujsmith/image_zpse70599cc.jpg (http://s1292.photobucket.com/user/smujsmith/media/image_zpse70599cc.jpg.html)

Seems we still have a bit of cash to throw at new aerospace projects. Looking at the company web site there are lots of civilian applications mentioned. Has anyone any idea of potential Military applications for this project ?

Smudge

[parabellum]

Surprised they can use the name Skylon, back in the early fifties there was a Skylon at the Festival of Britain, on the South Bank, don't think it had any useful purpose at the time, (unless it was connected to GCHQ!), possibly copyrights expire after a certain time?

[500N]

Trademarks, Company names etc do expire if you
don't keep them registered !

[CoffmanStarter]

Potential Nimrod replacement ... flown by a F/L Dan Dare ?

I know hat, coat >>>> door

[t43562]

I've no special knowledge of Skylon or military applications but I have read up on it quite a lot:


The Skylon vehicle is optimised for a particular purpose - dropping stuff off in low earth orbit cheaply. If that has a military use then you have an answer. It's not a bomber.
The payload can be attached to a kind of tug that pushes it into geostationary orbit then comes down and is retrieved by Skylon. The tug can be reused on some number of flights so the overall effort is still cheap.
A civil airliner version of the engine technology has been studied (see Lapcat A2 - Reaction Engines Ltd - LAPCAT A2 (http://www.reactionengines.co.uk/lapcat.html)). I can imagine this being turned to some military purpose but it's very big (makes an A380 look like a midget) and probably very expensive. Having a 20,000 km range and being able to do that in under 5 hours with 300 passengers might be something in itself.
The heat exchanger technology required by their SABRE and Scimitar engines has been described as too expensive for other than space applications. I would be surprised if this continued to be the case indefinitely and that might mean that ordinary jet engines could become more efficient via some adapted version of it. Presumably that would have military impact.

[iRaven]

Looking at the picture above ^^^^^

That's a big rocket to put a very small LEO satellite into space! :}

On a more serious note, haven't we trying to do this for years? I seem to remember something called HOTOL that looked spookily familiar.

iRaven

[t43562]

Skylon was designed by the same people who designed HOTOL. It is their way of getting around all the problems they encountered on the first attempt.

It's large because it is powered entirely by liquid hydrogen (relatively low density) and liquid oxygen and because nothing falls off it at any point - unlike multi-stage rockets. The design life is 200 flights per vehicle which is what gets the cost per flight down.

The design they show people is the C1 configuration with a 12 tonne payload to an equatorial orbit. They don't show off their D1 configuration which I believe carries 15 tonnes with better performance.

The heat exchangers in the engines are the primary enabling technology and a lot of effort has been put into proving them for that reason.

A way to sum it up is that the heat exchangers allow them to not have to carry 250 tonnes of liquid oxygen onboard which they get from the air as they ascend instead.

[ORAC]

it's an interesting technology, but the government shouldn't invest, for the following reasons.

£60M, or even £250M is peanuts and won't get you an end product, look at the sus Boeing and Airbus pour into an update for an existing design; similarly RR, PW in engines.

If the technology works then it's already been stolen by the USA and China and massive amounts, $250M a month or quarter, will be be being invested to get black one-shot space capability - which the maker will feed back to their commercial products.

Even if it works, the space market is a closed shop with just a few purchasers with existing and planned products, who will buy?

Concorde proved that the commercial market for high speed flight is minute, most people will save their money and fly as economically as possible, and video conferencing/web continues to shrink the market. Seriously, which airline would even consider buying someone of this nature?

Lovely concept, but it won't fly.... at least not in the UK/Europe.

[LowObservable]

It's a very interesting concept that does, indeed, build off HOTOL. Conceptually, the same sort of thing (single stage, close enough to orbit to need only a small kick stage) has been looked at before, and it is more attainable than true SSTO.

One problem is that the space business is now built around expendables, with a large and (until SpaceX) government-subsidized launch industry and big, long-lived, expensive spacecraft. The volume of large launches is therefore small, and consequently a big upfront investment in a launcher with low recurring costs is unattractive.

Another problem is that SpaceX has moved the cost bar, and is working on reusable technology, if not as flashy as Skylon's.

On the other hand, Skylon's technology would also be a way to get to hypersonic point-to-point flight without getting into the hairy aero-thermo-physics of scramjets.

[t43562]

I'll just mention that Skylon is the spaceplane and is not some kind of Concorde replacement. Reaction Engines are interested in space access, not flying in the atmosphere. The Lapcat aircraft was studied because the EU were prepared to pay for the study but it's not what RE are interested in.

If we really believe we should give up because everything's going to be stolen then we might as well all go home and quietly gas ourselves. Since we don't intend to do that, we might as well make an effort and invest.

60 million will pay for a lot of technology to be developed of which much could have application in the here and now. They already have a precision manufacturing company (Brite Precision (http://www.briteprecision.co.uk/)) for example which already puts their developed ability to use for other purposes. A government investment will help them with acquiring private finance too.

As Rolls-Royce etc are benefiting from the great investments of the past such as the RB211, it might be said that one can't afford not to make investments from time to time.

SpaceX etc have done well but they haven't actually delivered reusability yet. In any case the RE claim, accept it or not, is that the market can't grow without cheaper access to space and that providing that access will fuel the demand.

[Danny42C]

They'll never get me up in one of those things !

D.

[ImageGear]

I humbly submit to this esteemed group that a rethink regarding who steals what might be in order - yes it's true, every new design or concept is being stolen by everybody, so perhaps it's time to develop international partnerships which include China, Russia, India and the USA with commitments to joint funding and effort.

If no one comes to the party, nothing gets designed or built, if one of the parties do not divvy up their cash share, or do not commit the resource, the programme stops dead and everybody takes what they have at the time. All knowledge and assets are pooled.

You want to make a weapon out of your engagement, go for it, everyone else will know your capability and can build the same thing.

No secrets, no under the counter deals, just plain and simple mutual benefit for mankind.

It's the sun I tell you, he must be off his rocker, it'll never work, well consortiums have worked before notably Airbus, Military and Commercial and a few others so to extend it across more diverse nations can't be political rocket science.

Back in my hole now and wait for the incoming.

Imagegear :ok:

[Lima Juliet]

Not too sure on the design, though. If you get an engine flame-out on one side, I'm not at all convinced that tiny fin and rudder will do much! :eek:

LJ

[t43562]

I wish I could insert this image directly but it's outside the size guidelines. It's a very good cutaway diagram that summarises the whole thing very succinctly;

http://www.cosmonline.co.uk/sites/default/files/pictures/Skylon_1.gif

[CoffmanStarter]

t43562 ... Just helping :ok:

http://i1004.photobucket.com/albums/af162/CoffmanStarter/Skylon_1_zpsfae390fc.jpg

CREDIT : Graphic by Ben Gilliland.

[t43562]

Cheers, CoffmanStarter! :-)

[Just This Once...]

The Sabre engine on the right of the picture looks a little bent...

http://www.lechatnoirboutique.com/prodimages/Coffee%20Mug%20-%20Far%20Side%20Rocket%20Scientists.jpg

[Windy Militant]

The RB545 Swallow engine is supposedly flying on the Aurora in the US of A if the tinfoil and Peanut butter brigade is to be believed:suspect:
The Sabre engine on the right of the picture looks a little bent...
It's meant to be it's something to do with the thrust line. ;)

Got to go, the bloke on the black unicycle is wobbling up the road, Cuts eh! :rolleyes:

[Dysonsphere]

might have missed something are they looking at ground lift off or a airbourne launch make a big differance

opps just look at coff post properly. However mother launch might be better.

[Onceapilot]

Great engine concept for an air breathing, high atmospheric vehicle. But, for space, no chance. Half the world length runway and Two-hours(!) to 28km.
Money is being spent to support air breathing engine development IMO. Also, the blurb states re-entry is slower than shuttle due to low weight, yeah right, light things orbit slower than heavy things:ooh:.....not!

OAP

[smujsmith]

Some interesting input here chaps. Maybe, at the moment there is little or no direct military use for this beastie, however, that's not to say there never will be. Also spinoffs from development, could well find their way into future Mil. Projects. Did Concorde not benefit from reheat, surely a product of military research ? I also like the statement that basically, if no one gives it a go, no one will and we may miss a new phase of development. It all looks a bit Fireball XL5 to me, but then, as Danny42C says, "you'd never get me up in one of them things".:ooh:

http://i1292.photobucket.com/albums/b572/smujsmith/image_zpsf5fba06b.jpg (http://s1292.photobucket.com/user/smujsmith/media/image_zpsf5fba06b.jpg.html)
OK Venus ? OK Steve.

Smudge :ok:

[Herod]

light things orbit slower than heavy things.....not!

er...mass?

[CoffmanStarter]

Smudge ...

This is more like it :ok:

http://i1004.photobucket.com/albums/af162/CoffmanStarter/image_zps4cf767b7.jpg

Best ...

Coff.

[Onceapilot]

Herrod mate, read the blurb, they say "lighter". Still wrong with Mass anyway.

OAP

[MG23]

SpaceX etc have done well but they haven't actually delivered reusability yet. In any case the RE claim, accept it or not, is that the market can't grow without cheaper access to space and that providing that access will fuel the demand.

The problem is that you end up spending billions of pounds up front to develop something whose projected cost to orbit, if it works, is about the same as a reusable SpaceX Falcon.

In the long term, to reduce cost much further than that requires a single stage to orbit launcher rather than a multi-stage launcher with reusable stages. But there's no sane business case to get from here to there, while SpaceX can be making money as an expendable launcher while they build up to reusability.

[NutLoose]

Oddly enough, I looked at it and instantly thought Fireball XL5, but one didnt want to show ones age :p

The name strikes up a similarity too... Still a damn good Battlestar should see them off......... by your Command

:O

[CoffmanStarter]

Nutty then it would be a cylon :cool:

[VX275]

Incidently, Alan Bond the chap behind HOTOL and Skylon has admitted in the past that he was inspired by the XL5.
Come on Alan, you know no one is going to biuld you a very long runway when we all know Gerry Anderson was right with the railway launch solution nad XL5 is a better name than Skyon.
OK maybe the 'kicker' at the end of the XL5 launch rail isn't exactly practical but it will allow the craft's undercarriage to be a lot lighter (landing mass only to support).

[smujsmith]

Coff, #23

You're right, that's a mean looking ship, with Blue Steel too. Thanks for that.

Nutloose,

Age is of no consequence when you've watched the original series :)

Smudge :ok:

[Sir George Cayley]

Calling Capt Steve Zodiac, Capt Zodiac your new Fire Balls are ready!

SGC

Space Patrol was better btw.

[Agaricus bisporus]

Isn't it a pathetic, tragic indictment on our self-destructive mentality that when such a potentially world-changing BRITISH invention is showcased all we can do is descend into sub-moronic comparisons with a puerile 40 year old children's cartoon TV show?

F*** me. No wonder this country is going to the dogs.

[smujsmith]

Sir George,

Captain Larry Dart, Slim and Husky were indeed "proper" heroes of the puppet diaspora. I'm torn between the two. I do say that Stingray and Thunderbirds was not my thing. Good point well made Sir.

Smudge:ok:

Mushroom;

As for moronic puppet series. Is it a crime to enjoy a memory or two these days ? Perhaps I should queue up for my Liverpool Care Pathway now, before its cancelled. Get a life mate !

[CoffmanStarter]

Button old chap ... we're just having a bit of fun ;)

Anyway ... you can't tell me that Scottish Aviation didn't get a bit of inspiration for the Bulldog T1, or Hunting with the JP, from uncle Jerry :ok:

http://www.cageyfilms.com/wp-content/uploads/2013/03/supercar_01.jpg

Coff.

[smujsmith]

Blimey Coff,

I knew a QFI at Cranwell who was the double of your pilot in the picture. Obviously, a self portrait.:eek:

Smudge

[t43562]

The audio clip from Alan Bond is the interesting item in this page:

BBC News - UK government excited by 'disruptive' Sabre engine (http://www.bbc.co.uk/news/science-environment-23332592)


The bit that was new to me was their intention to bring the manufacturing of their heat exchangers entirely in-house and use that as an opportunity to work out how to reduce the cost by a factor of about 10. It is of interest because it might enable the idea to be applied to all sorts of areas outside space including ordinary jet engines.

[BEagle]

The Skylon project is so typically British - a brilliant piece of engineering and an idea that might never see the light of day. But at least it now has some funding.

Let's hope that it will succeed!

Coming from an era when Muffin the Mule was still legal, I personally consider those awful kids' puppet science fiction shows rather poor.

Whereas 'UFO' with ladies such as Wanda Ventham and Gabrielle Drake.....:ok:

[smujsmith]

Beags,

I've heard of Muffin the mule, and I understand it was very popular in your youth, its nice that in our more enlightened times people can feel free to out their little foibles :rolleyes:

Re reading the Reaction Engines Limited web site blurb on the SKYLON, it does mention a payload bay mounted "Personnel and Cargo Compartment", at a stretch I could see a capability for very rapid deployment of say, an SAS team to a distant area in a hostage situation. Although I suspect we would need some seriously good economic news to justify it. Mind you, by the time it's developed the SAS will probably all fit in it. It's hard to see any real military options without knowing its true capabilities, but as a few have said maybe the engine technology could be adapted to military use.

Smudge :ok:

[turboshaft]

Having heard all the same promises about paradigm shifting technology 30 years ago...and 20 years ago...and 10 years ago it sounds like an albino pachyderm to me, albeit a hypersonic one.

[Wetstart Dryrun]

I really fancy that Lady Penelope.

Is this normal or am I in a splinter group?

wets

[smujsmith]

I hope we are not creeping in to impropriety here, the mods will surely decide, and I accept my part in it, but giving ex , or existing, servicemen an outlet for their " deviances"? Would surely constitute a breach of the code of reasonable conduct, which is a credit to these forums.:ok:

My original post regarding Skylon was well and truly covered in a few, well thought out posts. I, like many, will wonder if, despite the latest inject of taxpayers money, this project will realise any major benefit to our country. Lets face it, we sold the jet engine for peanuts to our cousins over the water. I really hope this goes well, for no other reason than it would encourage British engineers to develop a new branch of aircraft propulsion. It's right as a country to invest in our scientific and industrial base, my concern would be funding a British invention for a "Foreign" advantage.

"Muffin the Mule" may turn out to be a very relevant phrase if we fail to back our own technology and "allies" take advantage of our weakness.

Smudge

Wets,

I suspect you have just opened a whole new "branch" of thinking. :D

[CoffmanStarter]

Smudge ...

Our BEagle has a bit of a thing for surplus RAF Firemen's vests :E

http://i1004.photobucket.com/albums/af162/CoffmanStarter/ScreenShot2013-07-18at212628_zps684eef4c.png

Crap on my BBQ indeed ...

Coff.

[smujsmith]

Aahhh Coff,

What I must have missed whilst the likes of Beagle loitered waiting for a mission on tanker force. BTW, is that how he insisted his loadie dressed ? And thanks for showing me why I'm stuck at Gerry Anderson and not Paul Raymond. Once again I find myself indebted to my "seniors" and "betters" for enlightening my knowledge, and, providing further research material. :eek:

Smudge :ok:

A little aside,

An Albert Captain and myself once shared a quiet moment, down the back, having a ciggy, after landing at HKG. We got to discussing the loss of the rudder system in flight. Captain says, no probs for me, "I would just use differential engines to control the yaw and land the bugger". How would you fix it ? He asked. "Well, as we are sitting in HKG I would suggest you get used to your hotel room", a rudder booster pack change would require the bits and a couple of lads from Lyneham. 3-4 days minimum. How easy it would have been had Skylon from BZN been available for spares and blokes in around 5 hours. And what a treat for the lads from the line.:ok:

[Warmtoast]

SKYLON

Going back to the original use of the word for a feature of the 1951 Festival of Britain I attach a couple of photos of postcards from my album.

It was 62-years ago on this day (18th July 1951) that I visited the South Bank and marvelled at the apparent impossibility as to why the Skylon stood as it did.

As I commented in my diary at the time I was on my way to 5FTS (RAF Thornhill), Southern Rhodesia (Draft 2128) via Southampton.
The draft departed RAF Hednesford in Staffordshire early in the morning of 18th July for London by train via Rugeley. Later at Waterloo and with hours to spare before we caught the Southampton train most of the Draft visited the Festival of Britain on the South Bank adjacent to Waterloo station.

http://i145.photobucket.com/albums/r231/thawes/RAF%20Thornhill/Postcard2_zps7de1b21c.jpg

http://i145.photobucket.com/albums/r231/thawes/RAF%20Thornhill/Postcard1_zps0cbd2965.jpg

[CoffmanStarter]

Great pics Warmtoast :ok:

These days the name of "Skylon" lives on as a Bar and Restaurant ...

Skylon (http://www.skylon-restaurant.co.uk/)

http://www.southbankcentre.co.uk/assets/wysiwyg/skylon_new_image_09.jpg


Not bad actually :cool:

[BEagle]

In the old ULAS bar, there used to be a plaque which included a piece from the original Skylon, plus a photo showing a ULAS scarf flying from the top of the Skylon. I gather that a ULAS student had scaled the structure and tied a scarf to the top..... The plaque was a memento.

That string vest looks rather better on the delectable Georgina Moon than presumably it ever did on any fireman....

[t43562]

ESA is looking into the payload delivery systems and other factors that might make Skylon useful to it.

Skylon to be studied as potential ESA launch vehicle (http://www.sen.com/news/skylon-studied-as-potential-esa-launch-vehicle.html)

A video of operations which shows, amongst other things, how it gets payloads into geostationary orbit from low earth

42682980

If the tags don't work then here's the link:
SKYLON - Operations on Vimeo (http://vimeo.com/42682980#)

[t43562]

Reaction Engines Ltd - News: Press Releases (http://www.reactionengines.co.uk/press_release.html)

Monday 26th January 2015

FIRST SABRE DEVELOPMENT MILESTONE REACHED

Reaction Engines Ltd announces company growth and completion of first SABRE development milestone
This year, the Reaction Engines team are expanding in staff and activities to complete the SABRE demonstrator programme, with delivery on track for 2019. The company has relocated to larger premises on Culham Science Centre; consolidated its two manufacturing subsidiaries to a single new location in Didcot; and is recruiting across the company, ready for the design, manufacture and testing of the full SABRE engine cycle. This growth phase has also included the purchase of new, bespoke equipment which will enable Reaction Engines to manufacture its proprietary SABRE pre-coolers in-house, at full scale.

The key development activities over the first year of this programme have centred on intakes and combustion systems. This activity includes the recently completed Preliminary Requirements Review development milestone, and has been 50% funded by Reaction Engines’ private capital. Matching funding has been provided by the UK Space Agency, through the European Space Agency. With the UK Government’s commitment of £60m and private capital secured towards the next steps in this development phase, the Reaction Engines team are positive that a full static demonstration of the SABRE engine is achievable before the end of the decade, marking the greatest advance in propulsion since the jet engine.

Alan Bond, Managing Director and Chief Engineer at Reaction Engines Ltd, commented:
“The technology we’ve proven, and our ability to integrate it with both rockets and gas turbines to create SABRE is not just a means to a better rocket. This is the beginning of a new generation of propulsion, enabling faster, more efficient transportation both on Earth and in Space. We’re already seeing humanity gaining huge benefits from space-enabled services, and I believe that our connection with space will grow considerably in the near future; Reaction Engines are breaking down the biggest barrier, which is getting into orbit in the first place. We’re opening the gateway to the solar system."

[JFZ90]

Positive news, but I do wonder where the capital will come from to build the final vehicle. Iteresting if it could really be an ESA sponsored replacement for Ariane 6, or perhaps NASA/US commercial rocket companies could stump up the cash?

Not really related, but sad to read about the final demolition of the national engine test facility recently. Maybe the M2/60,000ft cell might have been useful for SABRE, though it was shut down around a decade+ ago so well beyond recommissioning I guess - I seem to recall only EJ200 was really keeping it open towards at the end.

http://www.gethampshire.co.uk/news/local-news/pyestock-demolition-completed-make-way-7635622

[tartare]

It would be wonderful if SABRE works.
The BBC doco on it was very interesting.
IIRC the claim is that the pre-cooler drops the temperature of the hypersonic airflow by 100 degrees in a hundredth of a second.
Seems extraordinary... but then again, may be there was a good reason for the Govt classifying the original RR design back in the day...

[Willard Whyte]

The biggest threat to Skylon is the British government's 40+ year history of timidity towards space projects.

We remain the only nation to have successfully developed (Black Arrow) and then abandoned a satellite launch capability.

[tartare]

True Willard.
It's a sobering experience to stand in the science museum and look up at Prospero, or look at Woomera on a map and think of what might have been.
Remarkable achievement, and usually draws looks of incredulity when you tell younger people Britain has in the past successfully launched a satellite, using its own launcher.

[Willard Whyte]

Ascension Island could have been a decent 'spaceport' too. Close to the equator, decent climate, and not many people to p*** off.

[Lima Juliet]

Back to BEagle's Skylon and ULAS scarf story...

A few days before the King and Queen visited the exhibition in May 1951, Skylon was climbed at midnight by student Philip Gurdon from Birkbeck College who attached a University of London Squadron scarf near the top. A workman was sent up a few days later to collect it.


I wonder if this is 3rd Baron Cranworth, Philip Gurdon?

LJ

[FlightlessParrot]

According to Wikipedia, the third Baron Cranworth would have been 11 at the time, a bit young for either Skylon climbing or entry to university. At the time, too, Birkbeck was hardly a baronial college, as it used to specialise in evening classes for the gainfully employed.

[t43562]

This article has some more interesting details about the actual staffing and what their manufacturing investments are:

Skylon spaceplane's inventor sees busy spaceports coming soon - Sen.com (http://sen.com/news/skylon-spaceplane-s-inventor-sees-busy-spaceports-coming-soon)

We’ve grown steadily. If we go back to 2009 we were about 15 people, and now we’re getting ready for quite a major ramp-up of staffing capability. We’re up at about 65 staff this week, and over the next year to 18 months, we’ll probably expand by about another 110 people....
....But now we’ve got to the point where we want to build heat exchangers like that on a regular basis, so we’re installing our own massive vacuum furnace and so on. Our own factory will take another year to 18 months to get operational, but then we’ll then be able to build heat exchangers for real spaceplanes! We’re putting in the facilities that we’ll need for future manufacturing in the company over the next 20 to 30 years.

[Bigbux]

Not too sure on the design, though. If you get an engine flame-out on one side,

Those are the "military application" MATRA rockets. Well on that budget it's all they could afford.

[t43562]

Tuesday 14th April: Skylon-and-Sabre-Bringing-Space-Down-to-Earth

Richard Varvill, Technical Director, Reaction Engines Ltd.

Royal Aeronautical Society | Event | Skylon and Sabre - Bringing Space Down to Earth (http://aerosociety.com/Events/Event-List/1934/Skylon-and-Sabre-Bringing-Space-Down-to-Earth)

Event venue:
AMRC Knowledge Transfer Centre, Brunel Way, Catcliffe, Rotherham
Address:
S60 5WG


Wednesday 22 April: The Sabre Engine

Alan Bond, Managing Director & Chief Engineer Reaction Engines Ltd

Royal Aeronautical Society | Event | The Sabre Engine (http://aerosociety.com/Events/Event-List/1686/The-Sabre-Engine)

After the student awards ceremony, Alan Bond will describe the progress to date on the development of his revolutionary hypersonic engine.


Event venue:
Weston Auditorium, University of Herts.
Address:
AL10 9EU

[t43562]

It's not full of new information and in a way could be presented in a more exciting way but I still found a few things that added to what I know and it's a good summary of the position.

I can't wrap it in youtube tags because it is on Vimeo, so sorry about that:

https://player.vimeo.com/video/124910371

[t43562]

Reaction Engines Ltd - News: Press Releases (http://www.reactionengines.co.uk/press_release.html)


AFRL Analysis Confirms Feasibility of the SABRE Engine Concept

Wednesday 15th April 2015

Reaction Engines Ltd. is pleased to announce that analysis undertaken by the United States’ Air Force Research Laboratory (http://www.wpafb.af.mil/AFRL/) (‘AFRL’) has confirmed the feasibility of the Synergetic Air-Breathing Rocket Engine (‘SABRE’) engine cycle concept.
The analysis was undertaken by AFRL as part of a Cooperative Research and Development Agreement (‘CRADA’) with the Air Force Research Laboratory’s Aerospace Systems Directorate (AFRL/RQ). These investigations examined the thermodynamic cycle of the SABRE concept and found no significant barrier to its theoretical viability provided the engine component and integration challenges are met.

Reaction Engines Ltd. and AFRL are now formulating plans for continued collaboration on the SABRE engine; the proposed work will include investigation of vehicle concepts based on a SABRE derived propulsion system, testing of SABRE engine components and exploration of defence applications for Reaction Engines’ heat exchanger technologies.

AFRL/RQ program manager Barry Hellman stated - "The activities under the CRADA have allowed AFRL to understand the SABRE engine concept, its pre-cooler heat exchanger technology, and its cycle in more detail. Our analysis has confirmed the feasibility and potential performance of the SABRE engine cycle. While development of the SABRE represents a substantial engineering challenge, the engine cycle is a very innovative approach and warrants further investigation. The question to answer next is what benefit the SABRE could bring to high speed aerospace vehicles compared to other propulsion systems. Although application of the SABRE for single stage to orbit space access remains technically very risky as a first application, the SABRE may provide some unique advantages in more manageable two stage to orbit configurations. Furthermore, the heat exchanger technology also warrants further investigation for applications across the aerospace domain."

Sam Hutchison, Director of Corporate Development at Reaction Engines Ltd commented - “The confirmation by AFRL of the feasibility of the SABRE engine cycle has further validated our team’s own assessment and conviction that the SABRE engine represents a potential breakthrough in propulsion that could lead to game changing space access and high speed flight capability. We look forward to continued collaboration with AFRL”.

SABRE is an innovative class of aerospace propulsion that has the potential to provide efficient air- breathing thrust from standstill on the runway to speeds above Mach 5 (4,500mph) in the atmosphere – twice as fast as jet engines. The SABRE engine can then transition to a rocket mode of operation for flight at higher Mach numbers and space flight. Through its ability to ‘breathe’ air from the atmosphere, SABRE offers a significant reduction in propellant consumption compared to conventional rocket engines which have to carry their own oxygen – which is heavy. The weight saved by carrying less oxygen can be used to increase the capability of launch vehicles including options for high performance reusable launch vehicles with increased operational flexibility, such as horizontal take-off and landing. Additionally, the SABRE engine concept could potentially be configured to efficiently power aircraft flying at high supersonic and hypersonic speeds.

[Hempy]

Liquid Hydrogen and Liquid Oxygen...what could possibly go wrong!! :ok:

http://vignette3.wikia.nocookie.net/ethics/images/f/fe/Challenger-disaster-myths-explosion_31734_600x450.jpg/revision/latest?cb=20130129201106

[Willard Whyte]

Mix any fuel and oxidiser and the risks are the same, I'd hazard a guess that the result of the o-ring failure would have been similar had RP-1 been used instead. Atlas had several launch pad failures using the very same kerosene derived propellant.

LH2 & LOX seemed to work okay in the second and third stages of the Saturn V rocket.

[t43562]

It's stupid of me to bite but just FYI that picture is of the Challenger explosion and "Disintegration of the vehicle began after an O-ring (http://en.wikipedia.org/wiki/O-ring) seal in its right solid rocket booster (http://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Booster) (SRB) failed at liftoff." So the carrying of hydrogen + oxygen was not the cause of the accident and, presumably, the event would have been fatal with or without the main fuel tank.

It's really the ability to operate repeatedly like an aeroplane without throwing bits off that makes Skylon of interest - it can be tested progressively and each flight is not a from-scratch untested vehicle. Mr Varville said in his talk that the failure rate of rockets is about a million times more than that of a civil aircraft. The idea of Skylon is to bring space launch closer to that civil aircraft reliability. So essentially if you want to see more explosions then by all means carry on launching expendable rockets.

[tartare]

Best of luck to them, and I hope they keep trying until they succeed - explosions or not.
Aerospace is so bleedin' boring at the moment.
When did everyone become so frickin risk averse and cautious...!

[rh200]

It's stupid of me to bite but just FYI that picture is of the Challenger explosion

Don't feel bad, its Hempy, we make allowances for him:E.

The shuttle itself, never had any failures on its own accord, the shuttle system on the other hand :sad:.

Liquid hydrogen and Oxygen is the go, the Venture star was going to be powered them. It would have been interesting to see how that went if it wasn't for the tank issues.

[Hempy]

I'd normally bite to that rh200, but my dear old dad always told me that it's considered unfair to engage in a battle of wits against an unarmed man..

For the rest of you, I'm fully aware that the photo is of the space shuttle, and yes, rockets are fueled with an oxidiser and a propellant. It's the suggestion that the engines may be used in a passenger craft that inspired my post. If you are happy paying for a trip on a flying bomb put together by the lowest bidder though, fill ya boots!

As Danny42C said, "you won't be getting me on one of those things!', I'll take my chances with Jet A1 thanks :ok:

[t43562]

For the rest of you, I'm fully aware that the photo is of the space shuttle, and yes, rockets are fueled with an oxidiser and a propellant. It's the suggestion that the engines may be used in a passenger craft that inspired my post. If you are happy paying for a trip on a flying bomb put together by the lowest bidder though, fill ya boots!Oddly enough the passenger aircraft engine design (SCIMITAR) doesn't need to carry any oxidiser as it remains within the atmosphere and below mach 5 so it can scoop up what it needs. The same precooling system is used to ensure that that incoming air doesn't melt the engine and is in a usable state for combustion.

https://spiral.imperial.ac.uk:8443/bitstream/10044/1/1456/1/EUCASS07_scimitar_5_08_03.pdf

[LowObservable]

It wasn't the LOX/LH2 mix that caused the trouble in the first place, however...

Interesting AFRL comments. I recall one enthusiast for air-breathing access to space remarking that a rocket climbing through the atmosphere was like a fish using scuba gear.

[Lonewolf_50]

t43562 (http://www.pprune.org/members/314659-t43562)

Thanks for the linked document. The "suitable airframe" upon which to mount the Scimitar (once a couple of the other issues get resolved in further R & D) would need some significant safety factors applied to things like cabin pressurization and seals, for FL's where it looks to be during cruise at Mach 5. (FL~ 800? based on Table 2)

[tartare]

Yes - very interesting paper with lots of lovely algebra.
And the two most interesting lines - right at the end:

The engine poses several design and development challenges in intakes, heat exchangers and nozzles, although none of these require fundamental breakthroughs in technology for their realisation.

Apart from the issue of
NOx formation the engine is considered a practical development from known technology.

[ORAC]

If fully developed, it would be a vehicle that could, almost daily, re-fuel and pop a payload into LEO. That thing might not be very big, but getting up there would be very cheapClyde Space wins Outernet contract (http://www.spacedaily.com/reports/Clyde_Space_wins_Outernet_contract_999.html)

Clyde Space (http://www.clyde-space.com/)

[Tourist]

BAE invests in space engine firm Reaction Engines - BBC News (http://www.bbc.com/news/business-34694935)

[Tourist]

......or apparently not?:\

[msbbarratt]

The brief history of SpaceX is illuminating.

Too Cheap To Re-Use
Their original goal was to make a disposable launcher so cheap that it didn't matter that it got thrown away. They did some clever engineering in support of this. For example, their rocket engine bells were made by making two skins about the right shape and crimping them together to form the cooling channels.

This is far quicker and easier than brazing together miles of tubing as was done for the Saturn V's F1s.

Ok, Gonna Have to Re-Use
However their more recent move towards attempting to recover the first stage for re-use suggests that they may not have managed to make the manufacturing cheap enough.

Need to Spend More on QC
Their most recent failure seems to be entirely down to inadequate quality control. A strut, bought from a supplier, did not have the required strength (and nor did some others still on the shelf), and a helium tank broke loose and compromised the structural integrity of the quiescent second stage.

This is entirely down to inadequate quality control on the part of their supplier, and an inadequate quality assurance process within SpaceX. The only way of fixing that is more process.

Add That All Up...
Add this all together and it stacks up to a business that is gradually learning why the government programs were so darn expensive. Getting every component exactly right every time is a ferociously expensive business.

Skylon
I'm far from convinced that efforts like Space X can make truly large cost savings in the satellite launching business. Arianne is highly reliable, long lived, and goes off regular as clockwork. If Ariannespace haven't yet (they've had plenty of time) managed to make their ordered-to-launched process as cheap as possible then I don't know who can. And they use solid boosters too, which is a massive cost saving over liquid fuelled rockets.

Skylon is a completely different proposition, and is about the only idea out there that doesn't involve manufacturing something large and expensive every time it's launched. If it costs something like £20million or less to launch it, it's a going concern.

Plus it would be one hell of a ride. I'm game!

[Royalistflyer]

MSBB got it right "Getting every component exactly right every time is a fericiously expensive business." But good engineering used to be what we could do ....... at least we could design it right. From what I've read of Reaction they seem to be going about this the right way, slowly stage by stage, getting each stage perfectly right, bringing as much in house as possible so as to keep quality control in their own hands. They can certainly seem to do the engines. Now if only we had a decent airframe manufacturer in the country who could begin the design process, this project might actually work.

[msbbarratt]

Small steps is indeed the best way to go. They haven't got an infinite pot of cash, and spending it on the bit that really matters has paid off; they've got more investment :-)

Britain's history in the space business is accidentally quite good.

We had a rocket, called it Blue Streak, meant if for use as an ICBM / deterrent but then realised it was obsolete before it ever came anywhere near going into service. Apparently we gave the whole lot to the French as a "please let us in the EEC" bribe. The French said merci beaucoup, pizouf, and now they have Ariannespace.

Disaster? Big opportunity missed? Perhaps, but not as big as all that.

I don't think anyone has ever made a lot of commercial cash running a launcher. Mainly the motivation is to get a capability for national security reasons. Ariane did that for the French, we did that another way.

Instead we concentrated on satellite building. There's the sites in Portsmouth, Stevenage, Guildford, bits 'n' pieces at the Rutherford Appleton labs, etc. Building satellites has proved to be highly profitable.

If Skylon ever gets anywhere, we (the UK taxpayer) have a stake in it. Sending up lots of payloads that can then be in-orbit assembled is ultimately more impressive than trying to launch all in one go (e.g. the International Space Station). "Impressive" can turn into big money, maybe.

[unmanned_droid]

I attended a RAeS talk given by Alan Bond, from HOTOL to SABRE, or something similar.

I was somewhat captivated by the concept of HOTOL as a student, but he, having been there and done it, was less so. According to this talk, it would never have worked.

It's clear that Skylon, or in fact any other mooted system is a way of keeping people interested in REL. The only interest is in developing the SABRE engine, and I think that that is completely the right thing to do.

If there was to be any serious work on a practical application, I would prefer to see work on a vehicle that can crack the ground-to-space tourism and science nut whilst building experience with the engine. This is a much more practical goal whilst providing a useful service, and experience. Whilst that is going on, there should be some work done on making a Skylon/commercial vehicle that can operate off existing runways. I'd love to see the system operate out of Fairford.

[t43562]

It's clear that Skylon, or in fact any other muted system is a way of keeping people interested in REL. The only interest is in developing the SABRE engine, and I think that that is completely the right thing to do.

Having read a lot of the blurb and seen the talks too, my understanding is that there's no point creating an engine without having a feasible concept spaceplane to stick it on otherwise how would you know what the engine should look like, how big it should be, whether it could actually get something into space?

Hence Skylon isn't necessarily their business and the end vehicle might be different, but it seems to me that there would need to be a very good reason for ignoring it altogether.

Regards,

Tim

[unmanned_droid]

Whilst I agree that you need some parameters to play to, that can be limited to a thrust class, and a flight profile to design the engine.

I can't see that the quad engine pod used on the Skylon is designed around the precooler requiring 4 units, although I'm not involved with REL, so not fully aware of the situation.

I deleted a sharp comment about getting the technology thoroughly checked out by AFRL...

[Onceapilot]

Too complicated. Might be some (mostly) air-breathing gas-turbine SST related potential in the technology, but not wing borne-to-rocket orbital flight with one type powerplant. Even if it could ever work, what is the problem with using an extra 250 tons of LOX? The foreseable future must be with more reusable, mature, reliable, rockets launching one-way loads or spaceplanes.:ok:

OAP

[TURIN]

Having read a lot of the blurb and seen the talks too, my understanding is that there's no point creating an engine without having a feasible concept spaceplane to stick it on otherwise how would you know what the engine should look like, how big it should be, whether it could actually get something into space?

Did Mr Whittle have a similar point of view? :E

[MG23]

Getting every component exactly right every time is a ferociously expensive business.

Except they don't. As evidence we have two shuttles lost in only ~130 launches, and infamous process errors like the tool left in the engine bay even though three people had signed paperwork to verify that it had been removed.

I'm far from convinced that efforts like Space X can make truly large cost savings in the satellite launching business.

In the long run, the only way to make flight to orbit cheap is to make the launchers reusable with minimal servicing. The question is whether you start with something that isn't reusable (SpaceX), and work up, or start by trying to build something that is reusable from the first launch (Skylon).

Skylon's problem is that, like all current single-stage-to-orbit-designs, the payload is small, it could easily become negative as the vehicle mass grows during development, and you have to invest billions of pounds up front before you can find out whether it's possible.

[TURIN]

Except they don't. As evidence we have two shuttles lost in only ~130 launches, and infamous process errors like the tool left in the engine bay even though three people had signed paperwork to verify that it had been removed.

One was lost due to a design fault (o-ring) albeit being operated outside its temperature limits. The other was lost due to FOD.

Dangerous business, space travel.

[MG23]

One was lost due to a design fault (o-ring) albeit being operated outside its temperature limits. The other was lost due to FOD.

If you count a piece falling off the vehicle as 'foreign object damage', yes.

[unmanned_droid]

Yep, anything that falls off a vehicle becomes FOD.

[MAINJAFAD]

Britain's history in the space business is accidentally quite good.

We had a rocket, called it Blue Streak, meant if for use as an ICBM / deterrent but then realised it was obsolete before it ever came anywhere near going into service. Apparently we gave the whole lot to the French as a "please let us in the EEC" bribe. The French said merci beaucoup, pizouf, and now they have Ariannespace.

Disaster? Big opportunity missed? Perhaps, but not as big as all that.

I don't think anyone has ever made a lot of commercial cash running a launcher. Mainly the motivation is to get a capability for national security reasons. Ariane did that for the French, we did that another way.

Instead we concentrated on satellite building. There's the sites in Portsmouth, Stevenage, Guildford, bits 'n' pieces at the Rutherford Appleton labs, etc. Building satellites has proved to be highly profitable.

If Skylon ever gets anywhere, we (the UK taxpayer) have a stake in it. Sending up lots of payloads that can then be in-orbit assembled is ultimately more impressive than trying to launch all in one go (e.g. the International Space Station). "Impressive" can turn into big money, maybe.


Yes we did have an IRBM called Blue Streak which was in fact based on design concept of Atlas and was powered by two Rolls Royce RZ2 engines based on the Rocketdyne S3D used on the US Jupiter IRBM. It was cancelled in 1960 due to the vulnerability of the system caused by the loading time of its LOX / Kerosene propellant. Though the UK had an option of building their own launcher out of it by mixing the deHavilland built rocket with the Black Knight research rocket built by SARO. The Tory government at the time pushed for a European programme which resulted in the European Launcher Development Organisation (EDLO) with the French and Germans providing the second and third stages and the Italians the front end (payload and shroud). There wasn't that much tech transfer at all (had there been the thing may have been successful), the French stage was very the agricultural in its design and used hypergolic propellant, while the Germans had massive problems in getting their hypergolic fuelled stage light enough and powerful enough to get the payload into orbit (plus the fact they were starting from scratch seeing all of their best people were in the US or East Germany). The testing regime was very step by step. Blue Streak on its own 3 times out of Woomera (the first flight was actually a failure as the rocket went out of control a number of seconds before scheduled shut down), plus 2 flights with dummy stages, the first of which was blown up by the range safety officer due to incorrect data from a tracking radar. the other three flights were successful. The next two flights had a live French stage which failed both times. After this, the live German stage was added and after the British and French stages had successfully lofted it to altitude, only for it to explode on ignition on the first attempt and fail to fire at all on the second. The final flight out of Woomera saw all three stages successfully operate, only for the Italian payload shroud to fail to separate which resulted in the satellite and the rest failing into the Indian Ocean. The final flight was from Kourou of an improved Europa II fitted with a solid propellant French forth stage. This failed due to somebody cross-wiring part of the guidance system. At this point the UK pulled out of the launcher program as it was discovered that Europa wasn't capable of putting a large enough payload into Geostationary orbit, plus the fact that there wasn't the money to do both Launchers and Satellites. So Mr Benn (the man in charge at the time), picked the satellite option, which has been very successful. The French then went the LOX / H2 propellant direction and produced the successful Ariane which is a very different beast in all regards to Blue Streak. (Plus having a launch site on the equator is very handy for putting up Comms sats as it allows heavier payloads to be lofted than from places like KSC for the same amount of propellant).

[t43562]

Having read a lot of the blurb and seen the talks too, my understanding is that there's no point creating an engine without having a feasible concept spaceplane to stick it on otherwise how would you know what the engine should look like, how big it should be, whether it could actually get something into space?

Did Mr Whittle have a similar point of view? :E


I don't know but he probably had at least some idea of what his engine would be required for. Whether it would fly fast or high or for long or may not have been all that critical as long as it could make something fly at all.

SABRE has to get a vehicle into space with enough payload to matter and that is a much more demanding requirement. Already they have gone through 4 engine designs because their models using Skylon showed them what the trade-offs would be. If one used a significantly different vehicle then I presume that some of those trade-offs would change and force yet another design to be done.

They have certainly made statements in the past about it being difficult to scale down the engines without making them uneconomic. I don't know if that's still valid but it's the reason they have given for not making a smaller vehicle to test the whole concept.

[Onceapilot]

So, a closed cycle helium expansion turbine to drive a 450,000 lb thrust air breathing axial compressor. Get real. It wouldn't work efficiently in a power station, only on paper as a theory.

OAP

[Torquelink]

BAE as an investor? Given their apparent total aversion to anything that involves commercial risk rather than guaranteed government cost+ business, I'm not sure they'll be much help to RE. They milked their civil aircraft portfolio as far as they could on minimal investment and then closed them down, flogged their share in Airbus etc. The only way BAE will help get Sabre in the air is if its attached to yet another minimal makeover of the 748/ATP or 146/RJ . . .

:*

[Tourist]

BAE as an investor? Given their apparent total aversion to anything that involves commercial risk rather than guaranteed government cost+ business, I'm not sure they'll be much help to RE.
:*

That makes no sense.

If BAe don't take risks, then surely the fact that they have just invested millions in the company means they don't think it is a risk?

You can't have it both ways.

Onceapilot

NASA, ESA and BAe all think you are wrong.

I'm willing to believe that you are a Nobel prize winning rocket scientist that knows better than them......

.....oh no, wait.


It is easy to sit back with no expertise and say "it'll never work" about all new inventions, and 90% of the time you will be right and can act smug, but it doesn't make you a decent human being.
If it weren't for those willing to strive and push the boundaries, we we would still be wearing hides.

[Onceapilot]

Tourist,
I can understand that the headline grabing concept is being used as a political means to invest some money in the spinoff R&D for other British developments.;) But, to suggest that the concept, as shown in their blurb, is practical surely hinges upon the adequate supply of Dilithium crystals from China which, too me, seems far-fetched.;)

OAP

[Torquelink]

That makes no sense.

If BAe don't take risks, then surely the fact that they have just invested millions in the company means they don't think it is a risk?

You can't have it both ways

Tourist - that's actually a good point and I was being (slightly) facetious which you probably have guessed from my suggestion of using warmed-over 748/ATP as the launch vehicle.

However, based on their track record to date, BAE will be betting on the ESA partner nations eventually stumping up funds to complete the project: both for the airframe and the engines. The amount they've invested is pin money compared to the total required but they see a reasonable chance of a government-cushioned pay-off as in virtually all the projects in which they invest. SpaceX they're not.

[Lyneham Lad]

An interesting and quite upbeat article on Flight Global. (https://www.flightglobal.com/news/articles/analysis-british-spaceplane-engine-concept-gets-cas-418612/?cmpid=NLC|FGFG|FGFIN-2015-1117-GLOB&sfid=70120000000taAh)

[t43562]

US Military Set to Unveil Concepts Based on Skylon Space Plane Tech (http://www.space.com/32115-skylon-space-plane-engines-air-force-vehicle.html?cmpid=514648)

Within the next year, the U.S. Air Force plans to unveil novel spacecraft concepts that would be powered by a potentially revolutionary reusable engine designed for a private space plane.
Since January 2014, the Air Force Research Laboratory (AFRL) has been developing hypersonic vehicle concepts that use the Synergetic Air-Breathing Rocket Engine (SABRE), which was invented by England-based Reaction Engines Ltd. and would propel the company's Skylon space plane (http://www.space.com/26753-skylon-space-plane-will-be-both-truck-and-bus-video.html).
....


The key SABRE technologies that AFRL, based in Ohio, will start work on later this year, and possibly fly in the future, are related to the engine's precooler. This device precools the air entering the engine at speeds greater than four times the speed of sound (http://www.livescience.com/37022-speed-of-sound-mach-1.html) (Mach 4). SABRE's precooler will cool such air from more than 1,832 degrees Fahrenheit (1,000 degrees Celsius) down to minus 238 F (minus 150 C) in one one-hundredth of a second. The oxygen in the chilled air will become liquid in the process.

[tartare]

US Military Set to Unveil Concepts Based on Skylon Space Plane Tech (http://www.space.com/32115-skylon-space-plane-engines-air-force-vehicle.html?cmpid=514648)

Really?
Fantastic if true - but wouldn't one want to keep this as an SCI programme?
If I interpret this article correctly it is hinting at designs for a USAF single stage to orbit spaceplane.
If it's really happening - wouldn't this be blackest of black?

[MAINJAFAD]

If it's really happening - wouldn't this be blackest of black? The X-30 wasn't a black program and this is basically the same.[/quote]

[t43562]

This is an example from BAE - it seems that it might be related to the work on the SABRE engine.

4OMAEEqORyY

[t43562]

Basically Reaction Engines have been able to unlock the 60M that the government wanted to give them without it being "unfair state aid".

They have scaled down their demonstrator so that it won't cost as much.

Also they are looking at co-operating with Orbital Sciences to build air-launched vehicles which could test their engine.

ESA commits to next stage of UK revolutionary rocket engine / Space Engineering & Technology / Our Activities / ESA (http://www.esa.int/Our_Activities/Space_Engineering_Technology/ESA_commits_to_next_stage_of_UK_revolutionary_rocket_engine)

Funding flows for UK?s ?revolutionary? Sabre rocket engine - BBC News (http://www.bbc.com/news/science-environment-36773074)

Reaction Engines Ltd - News: 12 July 2016 (http://reactionengines.co.uk/news_12jul2016.html)

Reaction Engines Ltd - News: 11 July 2016 (http://reactionengines.co.uk/news_11jul2016.html)

[Onceapilot]

Reusable/semi-reusable solid or liquid hydrogen + oxygen boosters will remain the cheapest payload to orbit, this side of the discovery of dilitiumn crystals. :8

OAP

[Willard Whyte]

Go back to your cave painting oap.

[tartare]

Just once in my lifetime I'd like to see a really exponential aerospace breakthrough.
Maybe this will be it.
Fifty years old; so just maybe I might get to ride on a Sabre powered hypersonic airliner in my 80s.
Or even less ambitious, perhaps a seat in cattle class on a blended wing body powered by some 200,000lb turbofan that uses less fuel than a VW Golf (I'm joking...)
A battery with energy density exceeding that of Jet A1?
Saw the rise of the Internet, the evolution of mobile phones, GPS... here's hoping...

[Onceapilot]

Glad to see you bring a new level of information to the topic WW, or maybe it is just straight forward abuse? Perhaps you could explain how you think this concept would actually reduce the cost of payload to orbit ?;)

OAP

[t43562]

It reduces the cost by being fully reusable - getting 200 launches out of each airframe at least. So far rockets:

a) Are only partially reusable in the case of those that can reach orbit.

b) Have a high failure rate.

c) It's not clear that any bits have actually flown twice other than on the suborbital Blue Origin.

d) have more limits about where they can be flown from.

Against that, it's expensive but against that it may have various spinoffs (e.g. military) which will reduce the portion of the development cost that has to be paid back entirely by launcher sales. So there are various ways to look at it.

I think it would be silly not to develop the engine and then assess from there.

[tartare]

Could not agree more.
The history of engineering as a discipline, let alone aerospace, is full of examples of pontificators and pessimists who knew better - and upstarts who raised a finger, took a chance and proved their doubters wrong.

[Windy Militant]

More news on Skylon
Funding flows for UK’s ‘revolutionary’ Sabre rocket engine (http://www.bbc.co.uk/news/science-environment-36773074?utm_content=bufferf0007&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer)

Also interesting to note that there's investment in RPE Westcott uk-space-agency-to-create-4m-testing-facility (https://www.theguardian.com/science/2016/jul/12/uk-space-agency-to-create-4m-testing-facility)

Something to consider is the number of patented technologies that REL have developed on the way, machining processes and a number of techniques which are used for cryo and space systems.

I'm hoping that they do launch a demonstrator from Prestwick and if they do my name will be on the petition to have it named fireball XL5! ;)

[Onceapilot]

Great! No one here understands the efficiency mismatch between the cooling ability of cryogenic fuel and its available capacity to cool superheated hypervelocity atmospheric gas (part) oxidiser (via an inert medium) across two thermal interfaces in a wingborne lifting body supporting the additional weight ( ie drag) of the industrial scale machinery necessary to achieve this process against, the efficiency of a booster loaded with pre prepared cryogenic fuel and oxidiser that requires only 150 sec to reach sub-orbital (nearly zero drag) space, in the competition to launch orbital payloads.
There may be applications for cryogenic fuel / atmospheric oxidiser engines and high-speed / very high altitude wingborne flight but, the efficient upward path to orbit is via the route of minimum time/drag as, I think, was illustrated by the Saturn V.:ok:

OAP

[t43562]

There may be applications for cryogenic fuel / atmospheric oxidiser engines and high-speed / very high altitude wingborne flight but, the efficient upward path to orbit is via the route of minimum time/drag as, I think, was illustrated by the Saturn V.

Fortunately Reaction Engines has plenty of people who know what they're doing and has had the US AFRL and ESA check their work.

Even a non-expert like me knows that SABRE's advantage is that its precooler is so light compared to the amount of cooling it does - this is the main item of new technology after all. The other great realisation was that air need not be liqufied - it just has to be cold enough to compress.

We also know that oxygen is relatively heavy so that you get a great advantage (in payload) from not having to carry enough to reach Mach 5 after which SABRE behaves like a rocket.

Presumably the engineers that have done the sums don't think drag has a significantly negative effect on this outcome. After all the complete launch is only something like 15-20 minutes of engine use if I remember correctly.

I don't know how efficient these different schemes are as I am not a rocket scientist. But I do know that the aim is cost per kilo to orbit, not efficiency.

[Onceapilot]

txxxxx, the skyflop "details" picture page you posted shows two hours to 28km.:ooh: Along with loads of carp such as: Space Shuttle landing speed 400 mph, lightweight equals "slower" re-entry!
There is no way that this concept will ever be built. High altitude air breathing hybrid engines may find a niche, maybe even for launching small Rockets into orbit!;)

OAP

[t43562]

Ah, I see, Trolling. Sorry :-)

[ORAC]

U.S. Air Force Lays Out Air-Breathing-Engine-Powered Launcher Studies (http://aviationweek.com/propulsion/us-air-force-lays-out-air-breathing-engine-powered-launcher-studies)

As part of its pursuit of breakthrough propulsion systems for high-speed flight and potential access to space, the U.S. Air Force Research Laboratory (AFRL) has spent more than two years studying the novel air-breathing rocket engine system concept invented by UK-based Reaction Engines Ltd. AFRL’s studies of the Synergetic Air-Breathing Rocket Engine (SABRE) cycle, which uses atmospheric oxygen and liquid hydrogen from a standing start to above Mach 5 when it switches to onboard liquid oxygen, have shown the concept is thermodynamically feasible. The engine and innovative precooler at the heart of the cycle are ultimately aimed by Reaction at a single-stage-to-orbit (SSTO) launch vehicle dubbed Skylon.

However, while SSTO remains a long-range goal, Reaction has recrafted its ground demonstrator to reflect smaller-scale potential applications in the nearer term. AFRL, which is meanwhile working in parallel with Reaction under a cooperative research and development agreement, is for the first time outlining details of how SABRE might be used to support orbital launch missions when configured as part of a two-stage-to-orbit (TSTO) launch system. Working with Atlanta-based SpaceWorks Enterprises, AFRL has defined two initial next-generation launch system concepts: A partially reusable TSTO with a SABRE-powered booster and expendable rocket-powered second stage, and a second fully reusable option incorporating a SABRE-powered first stage and a rocket-powered upper stage. “We asked, ‘What’s a nearer-term approach to do access to space with this very interesting engine idea and precooling technology?’ and came up with this two-stage-to-orbit system,” says Barry Hellman of AFRL’s High-Speed Systems Division.

The first system is designed to place a 5,000-lb. payload into a 100-nm orbit with a 28.5-deg. inclination from Cape Canaveral AFS.. Two missions were also analyzed to determine performance to a sun-synchronous orbit at 378 nm flown from Vandenberg AFB, California, and a proposed UK spaceport site in Newquay, England.

http://aviationweek.com/site-files/aviationweek.com/files/uploads/2016/09/26/DF-TECH-BOOSTER_1_USAirForceResearchLab.jpg

The partially reusable concept is based on a twin-SABRE-powered winged booster. Measuring 150 ft. long, or about 4 ft. longer than a B-1B bomber, the vehicle would carry the rocket-powered second stage in a lower payload bay. “The notional concept of operations is like an aircraft with a horizontal takeoff and landing,” said Hellman at the American Institute of Aeronautics and Astronautics (AIAA) Space 2016 conference and exhibition in Long Beach, California, Sept. 13-16.

“The vehicle would accelerate to almost Mach 4.5 before transitioning to rocket mode, when it would pull up while still accelerating,” he said. “We carry the upper stage inside so it does not have to have a payload fairing or thermal protection system (TPS). That also means it has to stage at a very high altitude of over 260,000 ft. and a low dynamic pressure of about 0.8 psf. It then boosts away to orbit while the vehicle turns away and returns.” Staging would occur at about Mach 8 before the vehicle begins a gliding turn toward the launch site and briefly restarts the engines in air-breathing mode for additional boostback.

“We assumed we would have conformal hydrogen tanks and that would be another technology challenge that would have to be solved to make this design work,” Hellman said. By placing the payload underneath, no large cranes are needed to load the vehicle, and “when we get to staging, we use gravity and the payload just falls away,” he added. Hellman conceded, however, that payload bay door design will require special consideration for the TPS to handle reentry.

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The vehicle’s propellant mass fraction (mass of propellant divided by the weight of the whole stage apart from the payload) “is about 0.43, and that is unheard of for access to space systems,” said Hellman. “That is what an air-breathing engine allows you to have. The bottom line is, the vehicle can make the mission with extremely low propellant-mass fractions.”

The second, fully reusable option consists of a 190-ft.-long scaled-up variant of the smaller booster and a reusable upper-stage booster. Designed to carry a 20,000-lb. payload to orbit, the 115-ft.-span booster and upper stage would collectively weigh about 1.3 million lb. at takeoff. The system would launch horizontally, and both stages would return for a horizontal landing. After deploying its payload, the upper stage would continue around the world and, with the cross-range capability of its 40-ft.-span, X-37B-like wing, recover to the launch site.

For the immediate future, the Air Force continues to focus on further evaluation of the precooler. “That is the biggest interest we have right now at AFRL,” Hellman said. “We have been looking at trying to get the funding to test the heat exchanger at higher temperatures, simulating conditions behind the inlet at Mach 3.5-5. It’s a very fascinating technology that has a lot of senior Defense Department and NASA officials excited. We are moving along slowly, though hopefully we will make more progress in the next few years.”

[AtomKraft]

Anyone else thinking 'M-21, D-21'????

Different purpose (maybe) but a strong resemblance to TAGBOARD. Just move those twin tails in a bit......

[t43562]

This has some information about the kind of engine that they are going to develop as a demonstrator (JSF-sized apparently)

Reaction Engines Refines Hypersonic Engine Demonstrator Plan | Technology content from Aviation Week (http://aviationweek.com/technology/reaction-engines-refines-hypersonic-engine-demonstrator-plan)

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[JAVELINBOY]

The original Skylon built for the 1951 Festival of Britain was partly built by a firm in Hereford, Painter Brothers I think they also built electricity pylons. There was talk of erecting a similar Skylon at a proposed enterprise zone in the City.
Festival of Britain Skylon 'inspiration' behind design - BBC News (http://www.bbc.co.uk/news/uk-england-hereford-worcester-17142884)

Just thought you might be interested having seen the earlier posts about the original.