back to article Revolutionary Brit-made SABRE hybrid rocket engine to burn in 2020

The makers of the newfangled Synergetic Air-Breathing Rocket Engine (SABRE) have secured the necessary funding to fire up their hardware by 2020. Reaction Engines – the Oxfordshire, England-based team behind the next-gen engine – signed a collaboration contract with the European Space Agency at the Farnborough Air Show on …

  1. Voland's right hand Silver badge

    More Eu funding to be renegotiated

    Right, so where does the funding for this come from after article 50?

    1. Potemkine

      Re: More Eu funding to be renegotiated

      ESA != EU.

      1. werdsmith Silver badge

        Re: More Eu funding to be renegotiated

        Indeed, both Norway and Switzerland are players in the ESA.

    2. Phil O'Sophical Silver badge

      Re: More Eu funding to be renegotiated

      From the European Space Agency, which was created in 1975 and is unrelated to the EU.

      1. Alan Brown Silver badge

        Re: More Eu funding to be renegotiated

        "From the European Space Agency, which was created in 1975 and is unrelated to the EU."

        Except that it gets most of its funding from the EU and the EU is likely to start using that to dictate terms.

    3. diodesign (Written by Reg staff) Silver badge

      Re: More Eu funding to be renegotiated

      All the money is coming from the UK government. The ESA is just on board to oversee the administration of part of it. Like a startup bringing in managers approved by investors. The UK gov bankrolls the project knowing that clever folks at ESA will be overseeing part of it as well as the UK Space Agency.


      1. allthecoolshortnamesweretaken

        Re: More Eu funding to be renegotiated

        "The ESA is just on board to oversee the administration of part of it. [...] The UK gov bankrolls the project knowing that clever folks at ESA will be overseeing part of it ... "

        <ukipmode> Aha! EUcrats controlling a British programme again! </ukipmode>

        1. werdsmith Silver badge

          Re: More Eu funding to be renegotiated

          With ESA involved as technical auditors, they will need to spend most of the money on lawyers to make sure that their NDAs and patents are water tight.

      2. Captain DaFt

        Re: More Eu funding to be renegotiated

        "All the money is coming from the UK government."

        <sarc>All that money being wasted on science and the future when Government agencies are going begging for the billions they need to spend on IT projects to cancel after the proper pockets are lined. It's an outrage I tell ya! *sputter* *fume*<sarc>

    4. Dan 55 Silver badge

      Re: More Eu funding to be renegotiated

      As with Schengen and GSM, the EU rocked up later and claimed the credit.

  2. petur

    mandatory EU/ESA link

    1. Anonymous Coward
      Anonymous Coward

      Re: mandatory EU/ESA link

      "The European Union (EU) and ESA share a common aim: to strengthen Europe and benefit its citizens. While they are separate organisations, they are increasingly working together towards common objectives. Some 20 per cent of the funds managed by ESA now originate from the EU budget. "

  3. Def Silver badge

    My first thought was:

    "2020! That's ages. :("

    Then I realised how close we are to 2020 already.

    Fuck I'm old. :(

    But still... keep up it, RE. The future's looking shiny. :)

    1. Anonymous Coward
      Anonymous Coward

      Re: My first thought was:

      A new report from senior faculty at Havard shows that 1998 was ten fucking years ago, despite only feeling like a goddamn week ago.

    2. Francis Boyle Silver badge

      Re: My first thought was:

      "The future's looking shiny."

      But keep in mind it's only three years till we get replicants.

      1. Bogle

        Re: My first thought was:

        Wasn't Roy Batty's inception date 8th January, 2016? The replicants already here ...

      2. AceRimmer1980

        Re: Shiny

        That's another franchise, also with a ship with engine pods on its wingtips.

        And got cancelled unexpectedly.


    3. bob, mon!

      Re: My first thought was:

      > "2020! That's ages. :(" <

      That's unbelievably soon! They'll never get a working plane by then!

      Well, maybe (probably) a drone.

      1. John Brown (no body) Silver badge

        Re: My first thought was:

        "Well, maybe (probably) a drone."

        I bet you can't guess what the plans are and always have been for Skylon!

    4. John Brown (no body) Silver badge

      Re: My first thought was:

      "Fuck I'm old. :("

      Yeah, you ain't go 2020 vision no more!

  4. imanidiot Silver badge

    Related to that previous message about ESA building an engine test stand in the UK as well?

  5. Anonymous Coward
    Anonymous Coward

    Meanwhile NASA prepares its Apollo v1.1 ...

    .... same old engine technology, but it will have touch screens (and maybe apps as well)!!!

    NASA really needs a reboot.

    1. ecofeco Silver badge

      Re: Meanwhile NASA prepares its Apollo v1.1 ...

      NASA needs funding, not funding cuts that been the norm for the last 30 years.

      1. A Non e-mouse Silver badge

        Re: Meanwhile NASA prepares its Apollo v1.1 ...

        I suspect it's more that NASA needs less involvement from politicians telling it what to do.

      2. Anonymous Coward
        Anonymous Coward

        Re: Meanwhile NASA prepares its Apollo v1.1 ...

        NASA needs to spend less cutting many bureaucrats that burdens it - spending those money in researches. The amount of funding of the old days won't return - they need to spend smarter and look further. And ask supplier to be innovative, not to repurpose old designs. Musk is more innovative than Boeing, Lockheed & C.

        Getting to the Moon or Mars won't have any beneficial impact unless the technology to achieve it is really innovative and cheaper. We've been already on the Moon with 1960s then "innovative" technology.

        Returning there with the same one - but maybe faster computers - is quite useless, but for some political propaganda.

        Reaching Mars more so. A one-off mission to state "we got there fist!" may be feasible, but then? Once you burned a lot of old technology to get there, what's the advantage? Some place in history books?

        1. AceRimmer1980

          Re: "we got there fist"

          Remind me to avoid those particular probes.

      3. Alan Brown Silver badge

        Re: Meanwhile NASA prepares its Apollo v1.1 ...

        Even at peak spend, NASA got less than the USA public spent on takeaway pizzas (or outboard motors) in the same year.

        Ironically most of those pizzas were consumed whilst watching rocket launches.

    2. phuzz Silver badge

      Re: Meanwhile NASA prepares its Apollo v1.1 ...

      SLS isn't using upgraded Apollo technology, it's using upgraded Shuttle technology.

      Which is a shame, because the modernised F-1B engine looked pretty good.

    3. cray74

      Re: Meanwhile NASA prepares its Apollo v1.1 ...

      First, I'm hopeful about SABRE. If it works, then it's a new tool in aerospace engineers' tool kits. Further, if Skylon works, then congratulations are in order. Skylon's taking about the most painful possible path to orbit and the engineers who make it work deserve a pint hoisted in their honor. Speaking of simpler approaches:

      .... same old engine technology, but it will have touch screens (and maybe apps as well)!!!

      Neglecting the specific improvements to the SLS's engines compared to their Shuttle, Saturn, and Centaur predecessors, there's something to be said for simple chemical rocket engines and vertical takeoff.

      Consider a single stage to orbit vehicle like Skylon, DC-X, VentureStar, SASSTO, Kankoh Maru, and so on. However you get your SSTO into orbit, you're basically building it to work one both ends of the rocket equation. You can manipulate specific impulse or you can manipulate the mass ratio, or you can try both.

      Delta-V (change in velocity) = Specific Impulse x G x natural log (launch mass / final mass)

      Short of getting plutonium involved rocket motors tend to top out at a specific impulse of 460 if you're running on hydrogen-oxygen propellants, and most rocket propellants end up in the 300 to 350 range. SABRE and assorted scramjets push into the realm of thousands (perhaps 3500 for SABRE) while they're got external air to supply oxidizer and much of their reaction mass.

      The mass ratio of rockets, their fully fueled mass divided by mass upon reaching orbit, tends to be a bit overlooked. Many designers of rocket-based SSTOs consider it impossible to get past a 10:1 ratio, while airplane designers rarely achieve so much as 5:1. Given the impact of a natural log function on any ratio stuffed into that end of the rocket equation and you're better off focusing on specific impulse. The problem is, the mass of your SSTO shouldn't be ignored. There are some design decisions that thoroughly bork your hopes of getting into orbit in a single bound.

      For example, SABRE is predicted to have a thrust-to-weight ratio of 14:1. (That's for the engine alone, not the rest of the spacecraft.) By many counts, that's good - better than most military afterburning turbojets (~10:1), and much better than scramjets (~1:2 or worse). But it sets a bound on Skylon's mass ratio, which will never be better than 14:1.

      Meanwhile, those same old rocket engines can get 75:1 (like the RS-25 shuttle main engine, which is limited by its low density hydrogen fuel), 100:1 (for the overbuilt F-1 Saturn V engine), to 150:1 (for the Merlin 1D).

      Another factor are structural details of your reusable SSTO, like fuel tanks. Your SSTO is going to be carrying this dead weight from the ground to orbit, so it's going to set a floor on the mass ratio. Denser propellants (like liquid oxygen and kerosene) may have tankage less than 3% of the mass they enclose, while hydrogen and to a lesser extent methane are considerably heavier at 7 to 10% of the mass they enclose. (The driving factor in tankage is internal pressurization and volume, not fuel mass, and low density propellants need high pressurization to suppress cavitation at pump intakes.)

      Liquid hydrogen, in particular, is a pain to store. Look at the shuttle's external tank: 100 tons of liquid hydrogen occupied 2/3 of its volume and required 1/2 of its mass, while 600 tons of liquid oxygen occupied the small nose section and 1/3 the mass. (The balance was in the intertank connector and other features. Yes, those values are approximate.)

      Liquid hydrogen embodies the worst of many features of a propellant for an SSTO: its tanks will necessarily have a high surface area per unit mass because of its low density, which adds to tankage mass, and it needs more pressurization for its pumps, which requires thicker tankage walls. I believe the shuttle ET favored about 15psi in the hydrogen tank.

      Liquid oxygen, at 16 times the density of liquid hydrogen, is much more manageable in terms of volume, tank mass, and tank pressurization. Some rocket motors need scarcely 1-2psi pressurization to get good LOX feed.

      Earlier, I mentioned that rocket-based SSTO designers considered a 10:1 mass ratio a practical limit. However, they were all considering hydrogen-oxygen rockets. The situation suddenly changes when you replace hydrogen with a denser fuel, like kerosene. Flown, operating hardware like the Saturn V's first stage, the Saturn IC, and the Atlas balloon stages achieved well above 10:1, like 15:1 and were headed for 20:1. (Obviously, they lacked reusable features like heat shields and landing systems.)

      You get the best of multiple worlds with dense propellant vehicles: the tanks are lighter and the engines have higher thrust ratios (thrust being limited by fuel entering the combustion chamber, and fuel pump horsepower being determined by pumped volume - a hydrogen/oxygen engine is thus lucky to get to 75:1, while a kerosene/oxygen has no trouble reaching 120:1 or better.) The more compact tanks for a given delta-V also means lighter heat shielding and lighter landing systems.

      An interesting point about rocket-based SSTOs is that the initial fuel mass doesn't matter that much. You're burning it all on the way orbit, after all. Only the residual structural details - engine mass, tankage mass, heat shield mass - that were influenced by propellant mass matter.

      A good, lengthy discussion of the tradeoffs may be found here, including a comparison of hypothetical hydrogen and kerosene SSTOs. comparison of denser SSTO fuels.

      So, how that all apply to Skylon and SABRE?

      Well, what Skylon is doing is:

      1) Trying to dramatically increase the specific impulse by using using an airbreathing engine for much of its flight (good idea)

      2) Trying to minimize carried oxygen mass, which doesn't win you much

      3) Retaining a full amount of liquid hydrogen, with problems discussed above

      4) Being very aerodynamic, which penalizes you with elevated surface-to-volume ratios and more structural dead weight

      5) Using engines of relatively low thrust-to-weight ratio

      6) Using a horizontal takeoff, which requires extra structure to hold the maximum mass of the vehicle along an axis different than its main thrust axis - the single main load direction of a rocket is simpler

      Skylon is making a lot of design choices that hinder its final mass ratio. Not necessarily to the point even SABRE won't help, but there's a lot of easy design options being tossed out in favor of the harder path forward. So congratulations are definitely in order if Skylon's engineers make it work.

      Meanwhile, the same old NASA technology does work, and does loft a large payload. The mass ratios needed for a rocket-based SSTO have also been proven in flight. If you don't muff it up by taking a difficult path, like Lockheed's VentureStar, reusable SSTOs aren't out of the question with that same old technology.

      1. phuzz Silver badge
        Thumb Up

        Re: Meanwhile NASA prepares its Apollo v1.1 ...

        @cray74, are you a rocket scientist? If not, maybe it's a career you should look into, that was a great explanation, I just wish I could give you more than one upvote.

      2. Alan Brown Silver badge

        Re: Meanwhile NASA prepares its Apollo v1.1 ...

        "Neglecting the specific improvements to the SLS's engines compared to their Shuttle, Saturn, and Centaur predecessors, there's something to be said for simple chemical rocket engines and vertical takeoff."

        Yes: They're not as good as a Lofstrom loop, but we don't have any Lofstrom loops.

      3. Alan Brown Silver badge

        Re: Meanwhile NASA prepares its Apollo v1.1 ...

        "Skylon is making a lot of design choices that hinder its final mass ratio."

        Skylon is designed to get people and biological fragiles safely to orbit and return them - safely.(*)(**)(***)

        If you want heavy lifting then call in a Falcon XX heavy.

        Assuming one device will be used for all loads was what turned shuttle into a fustercluck.

        (*) The vibration that launch loads are subjected to would literally liquify passenger brains if they weren't sat in expensive well-padded, vibration isolated seats, mounted on more vibration isolation and shock absorbers.

        (**) It's also the basis of a "skipper" for rapid longhaul flights (think of a stone skipping on a pond and visualise an aircraft which does the same thing, dipping into the atmosphere to light the engines and provide more thrust). 90 mins to 2 hours to Australia is good, as the vomit inducing ride would likely make anything longer completely intolerable.

        (***) Being bunged in a capsule which returns to the ground the way soyuz or dragon do might work, but it's not "safe" and it's certainly not what most revenue-paying passengers will put up with.

  6. AIBailey
    Thumb Up


    "... cool incoming air from 1,000°C (1,832°F) to –150°C (–238°F) in just a hundredth of a second, without icing up."

    That's some impressive technology right there! The amount of energy being dissipated that quickly is phenomenal!

    1. Rich 11 Silver badge

      Re: Wow!

      I just got 400MJ per second per engine (based on 300 tonnes of thrust). There are too many factors to take into account over that temperature and pressure range that I can't even look at it and say if that's a good approximation. *brain melts*

    2. danR2

      Re: Wow!

      Finally, a technical comment. I'm sorry to disappoint the 17 upvoters but this claim needs to be fully backed by a working model at working speeds and simulated altitudes. This hasn't been nearly done, and I don't believe it will ever happen. I don't even know of any supercomputer modelled device that validates the physics of its fundamental aspects. I suspect SABRE is delusion, no matter how many prestigious experts put their imprimatur on it.

      1. phuzz Silver badge

        Re: Wow!

        They have already run the pre-cooler at ground level (four years ago), so some testing has been done already. (Note that they heated the incoming air up to the temperatures they're expecting at Mach 5).

        To my mind this shows that they have demonstrated a working model at working speeds and simulated altitudes, and given that ESA have signed off on the testing so far, they agree. And they, after all, are rocket scientists.

  7. Matthew Smith

    I keep following this project, reading for news snippets about the latest trial, but all I find is new people being assigned to the board or articles about funding. I'm not hopeful theres something solid coming from this.

    1. Ian 7

      Anyone old enough to remember HOTOL? That ended well (and made me decide to curtail my budding career in aerospace engineering)... Fingers crossed for a bit more progress with this beast!

      On a positive note, all those "artist representations" of what HOTOL might look like are now getting a second airing with the new SABRE branding.

      1. Lotaresco Silver badge

        "made me decide to curtail my budding career in aerospace engineering"

        That's a shame. I worked in aerospace engineering and it was the best couple of decades in my life. Despite the cutbacks and the dearth of new projects interesting work is still being done by interesting people. Some of those who had to leave have gone on to have careers in general and commercial aviation, F1 racing, mainstream car design and "exotic" engineering projects like SABRE, UAVs and even <shudder> delivery drones.

        1. danR2

          You're confusing the issue by burying SABRE amongst a variety of technically and practically validated designs.

      2. Christoph

        HOTOL had to be redesigned as SABRE when they realised that putting the engines at the back was a bad idea due to the change of weight distribution as the fuel burned up. SABRE has the engines in the middle of the fuselage.

        I fondly remember an official illustration of what HOTOL would look like - the artist had even included painting in the ship's name on the fuselage. It was, of course, Anastasia.

        1. kmac499

          IIRC Hotol was to be launched from a sled and ramp system, shades of Fireball XL5. I think It was also tied up in all sorts of politicking and budget issues within Rolls Royce the MOD.

          I just hope that Alan Bond & friends are left alone to concentrate on the enginneering of SABRE and the various vehicles. The last thing they need now is a bunch of poiliticians or accountants poking their noses in,

      3. Esme

        @Ian 7 - it's the same people behind Sabre/Skylon - now having benefitted from their experience on the HOTOL project. There were stability problems with HOTOL due to the siting of its engines - Skylon sites its engines differently to solve this problem. getting the precoolers to work without icining up was, apparently, the biggest hurdle they had to overcome with the engine, and they seem to have got that one sorted. So far as I can see, pretty much all they need now is the backing to get a fully working prototype built - which, much to my surprise (given it was the government that halted progress back in HOTOL days), they now seem to be getting.

        This could be a very big deal. OK, so it won't lift as much to orbit as SpaceX's boosters, but the entire thing is recoverable. This could make it the vehicle of choice for lighter/compact cargo and crew delivery, with SpaceX and others handling the heavy lift side of things.

        It could, potentially, scupper Ariane, unless Ariane develops or licences booster fly-back technology.

      4. eesiginfo

        This is 'Son of HOTOL'

        This project is straight out of a Dan Dare comic, and all things being equal should have been lost to the world when HOTOL was scrapped.

        .... but this group of visionary engineers didn't give up. They decided to go it alone.... and succeeded.

        That's the WOW!

        The story is awesome, the characters in it are awesome, and the space plane is going to be truly awesome.

        I just cannot wait.

        1. John Brown (no body) Silver badge

          Re: This is 'Son of HOTOL'

          .... but this group of visionary engineers didn't give up. They decided to go it alone.... and succeeded.

          That's the WOW!

          I just found out that similar happened with Tommy Flowers. Initially he was sent away with a flea in his ear but built the prototype Colosus anyway, his team working unpaid overtime and with a 1940's value of £1000 of his own money.

          1. eesiginfo

            Re: This is 'Son of HOTOL'

            Tommy Flowers.

            Died penniless in an old peoples home.

            Turin got all the credit.... but he too was shafted by the state.

            Yes... these guys have succeeded against all the odds.... but still I look at the investment figures and wonder if they are developing the next generation of rocket propulsion on a shoe string.

            Great that they can do this, but I do question whether this project has received the full support that it deserves.

            You mention Tommy Flowers..... but let's not forget Frank Whittle.

            1. John Brown (no body) Silver badge

              Re: This is 'Son of HOTOL'

              "but still I look at the investment figures and wonder if they are developing the next generation of rocket propulsion on a shoe string."

              IIRC REL deliberately set themselves up to not be a government project so they could maintain control.

      5. LesC

        Looks like it's going to go like a scalded LAPCAT - Reaction Engines should call their first iteration of SABRE 'Fireflash' ok it doesn't have Anderson's preoccupation with wheels and wings everywhere but this baby could revolutionise LEO / terrestrial flight. And give Beardy / Musk a run for his money.

        Hopefully their next project is a recombination / Bussard ramjet or a scramjet along the lines of that Orbiter Delta Glider IV effort that I flew from London to New York in 35 minutes at around FL500 with the scramjets on at full blast (doing around Mach 8 at g/l the ground / rear view was somewhat fiery) although some dev could replicate the physics of SABRE on this beastie and it would still move along plenty quick :)


    2. Alister Silver badge

      It does seem to have been a long time coming, I agree, almost to the point of feeling like vapourware, I too have read about Reaction Engines, Sabre and Skylon, for well over a decade, without seeing much progress.

      However, I think that is probably due to a lack of funding, rather than issues with the underlying technology, and as we all know, trying to secure funding from the British government for any sort of technology that doesn't involve the BAE Systems pork barrel is doomed to failure.

    3. allthecoolshortnamesweretaken

      A vald point, so why the downvotes? Funding can dissappear much faster that it was granted. UK gov has a bit of a track record in not funding innovative flying thingies. Frank Whittle, Blue Streak, Black Arrow, HOTOL ... Well, let's just hope for the best!

      1. Graham Cunningham

        And don't forget...

        Saddest of all?

    4. danR2

      Same here. Where's the beef?

  8. kmac499

    If this was the last cheque George Osborne signed as chancellor it could be the one with the biggest payback ever. Can't wait to hear the Sabre roar for real.

    Yes it will have problems, and the nay sayers will moan about the money, but if anyone can make it work it's Alan Bond and REL

  9. Lotaresco Silver badge

    Dear Jeebus

    I'm not a religious man, but please make this thing fly.

    1. smartypants

      Dear Lotaresco

      I am PA to the Lord Jesu.

      The Benevolent One tends not to get involved in things these days. His 'water into wine' days are well and truly over! (How we laugh about that day though. It was much more fun than came across in the coverage in the Canaan Gazette)

      I suggest that you direct your requests instead to someone with an engineering degree and a spanner.

      Blessings etc..

      1. Lotaresco Silver badge

        Re: Dear Lotaresco

        "I suggest that you direct your requests instead to someone with an engineering degree and a spanner."

        I would do that, but then I would be talking to myself.

  10. Pen-y-gors Silver badge


    Yep, only 4 years away. But then that's (hopefully) a working engine. When does it actually make orbit with crew? 2040?

    By 2020 Elon Musk will probably have an operational manned space station around Mars!

    Sad difference between public and private projects.

    1. Lars Silver badge

      Re: 2020?

      "Sad difference between public and private projects.". Just not that simple.

    2. Anonymous Coward
      Anonymous Coward

      Re: 2020?

      Musk is pushing the actual technology envelope, and meanwhile it can earn money selling it. Truly innovative projects that may not have commercial applications for many years, while requiring funding, need to be supported in a different way.

      Musk in 2020 probably won't have an orbital station around Mars (it's just four years), but probably will have working reusable Falcons.

  11. Christoph

    £60 million?

    Aren't we lucky that the UK government is willing to devote such huge amounts of funding to the project?

    Why, that's enough to keep NASA going for several minutes!

    1. jason 7 Silver badge

      Re: £60 million?

      That or just the annual cafeteria bill.

  12. Paul Woodhouse


    some interesting good new for a change... More of this sort of stuff...

  13. AndrewDu

    "But what good came of it at last?"

    Quoth little Peterkin.

    "Why, that I cannot tell," said he,

    "But 'twas a famous victory."

  14. JimmyPage
    Thumb Up


    are these similar to what Concorde needed to slow the incoming air down (and explains the unique shape of the intake) ?

    Something NASA admitted put the Apollo program into the shade ....

    1. TitterYeNot

      Re: Precoolers

      "are these similar to what Concorde needed to slow the incoming air down (and explains the unique shape of the intake) ?"

      I dont think they're quite the same - jet turbines get unhappy if you squirt supersonic air into the internal intake, hence tricks to slow down the air to subsonic speeds before it hits the internal turbines and compressors.

      A SABRE engine is designed to run with intakes open at much higher velocities (i.e MACH 5) - I think that at those speeds, incoming air is compressed so much that it gets hot enough to start melting engine components, hence the need to cool it very rapidly before it reaches the internal intakes to the combustion chambers.

      One thing that puzzles me about the reporting of this story (on several sites), is that the SABRE engine is being described as using jet propulsion when in air-breathing mode, then rocket propulsion using internal liquid oxygen supply above MACH 5. As far as I'm aware, this motor has no turbines, so cannot use jet propulsion, and simply switches from being an atmospheric air breathing rocket motor to an internal LOX breathing rocket motor.

      Or am I missing something?

      1. Captain DaFt

        Re: Precoolers

        "Or am I missing something?"

        Just this.

        Although turbojets are what most people think of when they hear "jet engine", technically, any engine that provides thrust by a jet of high energy exhaust is a "jet engine".

        In fact, rockets are a type of jet engine. That's why These guys use it in their name.

    2. James Hughes 1

      Re: Precoolers

      Not really.

    3. kmac499

      Re: Precoolers

      No, you;re thinking of the dump doors in Concordes engine intakes, basically hinged flaps which slowed supersonic air to subsonic prior to the engine proper.

      The sabre precoolers do what It says on the tin cool very hot incoming supersonic air, which as a byproduct also slows it to subsonic speed. ready for the SABREs compressor unit.

      1. annodomini2

        Re: Precoolers

        No the air is slowed to subsonic speeds, that is why there a inlet cones on the front of the engine.

        Slowing the air causes compression and resultant heat. Hence the need for the pre-cooler.

        There is a compressor stage which feeds the rocket engine with air.

        It does not compress and cool to liquid, for the icing problem.

        HOTOL is a LACE engine Liquid Air Cycle Engine, this is a VACE Vapour Air Cycle Engine.

        It is not a Jet in the traditional sense, that is just poor understanding on the part of the reporter.

        It's an air fed rocket engine. They just happen to use a turbine to put the air into a format the rocket can use.

        1. Sweep

          Re: Precoolers

          A rocket engine is a type of jet engine. In common usage though a "jet" engine normally refers to an airbreathing engine that generates thrust by jet propulsion, exactly like SABRE.....

  15. johnwerneken


    Sounds like SABRE could if it scales be the Big Breakthrough

    1. nematoad Silver badge

      Re: Excellent!

      A couple of things about the names used in this project.

      1) Reaction Engines, lets hope that this company fares better that Power Jets, Frank Whittle's start-up which built his jet engines. Again Britain seems to be leading the field in this sort of technology, with luck this time they don't let others overtake them.

      2) The name Sabre, let's hope that it does not follow in the foot-steps of the last engine named Sabre. That was the Napier H layout piston engine that had so many problems that it nearly caused the cancellation of the Hawker Typhoon ground attack fighter.

      Fingers crossed for this one.

      1. IJD

        Re: Excellent!

        According to L J K Setright in his "Power to Fly" book, the Napier Sabre was initially dogged partly by some manufacturing problems but mainly by maintenance staff/pilots flogging the engines to death by running them under coarse pitch/full throttle conditions that should never have been allowed. Once these problems were fixed it became a reliable and very powerful engine, probably the highest power density piston aero engine ever built.

  16. drand

    A looooong few years

    I want Skylon to happen, but:


    We should see the engine test unit firing by the end of the decade – with a full aircraft expected a few years after that.


    Well it's a good job they've got it all spec'd, design chilled, supply chain prepped, prototype vehicle with conventional jets in build ready for SABRE integration etc. etc.

    Going to be very long wait.

  17. Anonymous Coward
    Anonymous Coward


    But you'll need a visa to fly it anywhere past the Isle of Wight

    1. Lotaresco Silver badge

      Re: Fantastic

      "But you'll need a visa to fly it anywhere past the Isle of Wight"

      They seem keener on MasterCard sur le continong.

    2. nematoad Silver badge

      Re: Fantastic

      "But you'll need a visa to fly it anywhere past the Isle of Wight"

      Oh? Care to explain?

    3. drand

      Re: Fantastic

      No need to even go as far as the Isle of Wight, just go straight up.

  18. John Brown (no body) Silver badge

    Just so long as jealous yanks....

    ...don't claim airspace jurisdiction up to 24,000 miles and refuse us entry "in case of loud bangs"

    Pint for the boy and girls at REL -------------->

    1. Anonymous Coward
      Anonymous Coward

      Re: Just so long as jealous yanks....

      If this thing flies they won't even see it go past, let alone be able to catch it.

      1. John Brown (no body) Silver badge

        Re: Just so long as jealous yanks....

        Yes, I can well believe the military are keeping a very close eye on developments. I'd not be surprised to learn that REL is bugged to hell and back by a number of "interested parties".

        1. annodomini2

          Re: Just so long as jealous yanks....

          They are already in talks with US aircraft manufacturers for supplying pre-coolers.

  19. YARR

    SABRE 2...

    If this project succeeds (and I hope it does), the next stage will be to optimise the design to increase the payload it can carry.

    (1) Would using a launcher e.g. like EMALS make a significant reduction to the fuel load?

    (2) Could oxygen be extracted from the atmosphere on the ascent (replacing the weight of used fuel) to minimise/eliminate carrying LOX for space flight? If this were possible, it would make sense to design the SABRE engine from the outset so that an air-supply can be fed back to the Skylon.

  20. Palf

    A British opportunity

    The name of the game is $/Kg launched, and if done right, Skylon would be at the head of the pack. It would be nice to get it done right. It will mean jobs and kudos and excellent future prospects for opening up space - finally.

  21. Lotaresco Silver badge

    While talking a lot of drivel...

    ... this morning on the radio. Vince Cable did make a good point in relation to ARM. That was that the technology sector in the UK is brilliant at innovating but as soon as the companies start to become global players they are bought up and either shut down to kill the competition or moved abroad.

  22. Louis Schreurs BEng Bronze badge

    £60m (US$80m)

    Yup, you using only £ and US$ and not € makes me supporting the Brexit, as an EU resident. Go Go Brits!!!!! pleese dont mind the speling errorrs.

    [edit] hehehe, did not read all when making a comment, so reading on reveals:

    The ESA will administer €10m


    so how much £ and US$ is €10m ??????????????????

    pleese dont mind the speling errorrs still true

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