back to article Brit rocket boffins Reaction Engines notch up first supersonic precooler test

Brit firm Reaction Engines has successfully tested its engine design's precooler heat exchanger – a key step on the path to getting its SABRE donk up and into space. The Synergetic Air Breathing Rocket Engine (SABRE) designed by Reaction is designed to get an attached space vehicle up to Mach 5.4 before switching to liquid …

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  1. graeme leggett

    So much potential

    If it works, it'll be amazing.

    Until then...

    1. Mr Catbert

      Re: So much potential

      Until then... It's still amazing!

      1. Doctor Syntax Silver badge

        Re: So much potential

        The really amazing application would be cooling the hot air emanating from politicians.

        1. Mr Catbert
          Joke

          Re: So much potential

          Given what we've seen over the past few weeks, I'm pretty certain that there's not a working fluid that can cool that sort of heat load. That said, dropping them all into the middle of the Atlantic might work!

          1. A.P. Veening

            Re: So much potential

            That said, dropping them all into the middle of the Atlantic might work!

            That is an environmentally unsound policy. Besides, you would create an artificial island where they can breed even more of them.

          2. macjules Silver badge

            Re: So much potential

            Unfortunately dumping them into the sea would not work. Sharks or other man-eaters would, out of professional courtesy, not touch them or you would get Greenpeace launching protests at the introduction of criminals into the food chain.

            A far more sensible option would be to tether them in bunches of 10 behind the engine in order to test the minimum distance for those observing the afterburner.

          3. Ian Michael Gumby Silver badge
            Trollface

            Re: So much potential

            That said, dropping them all into the middle of the Atlantic might work!

            That said, you would indeed prove that those who say that climate change is man made because the combined hot air from said politicians would quickly melt the icebergs, causing sea levels to rise dramatically and causing most of the UK to be flooded. (Unless you live in the Mountains of Scotland. )

            So sure. that would be one way to solve Brexit... flooding London along w most of low lying Europe.

            Then on the other side of the pond, most of the US East coast would be under water. Think of all of those yuppies on Wall Street treading literal water.

            1. jake Silver badge

              Re: So much potential

              "Then on the other side of the pond, most of the US East coast would be under water. "

              And those of us on the West side of the Rockies would party.

              1. A.P. Veening

                Re: So much potential

                And those of us on the West side of the Rockies would continue to party.

                FTFY ;)

          4. CrazyOldCatMan Silver badge

            Re: So much potential

            not a working fluid that can cool that sort of heat load

            Bose-Einstein condensate? Has the advantage of being very, very, very cold and very, very low pressure. Which means that the heat output of said politician surrounded by BEC would rapidly diminish..

        2. Symon Silver badge
          Coat

          Re: So much potential

          @Dr. S. "You want two lanes or four lanes on that bridge?"

    2. Mr Benny

      Re: So much potential

      So much potential .... to pollute the atmosphere ever more by making launches simpler and cheaper. I guess its not enough to screw up the stratosphere with burnt kerosene from the thousands of jets up there at any one time, lets make sure we mess up every level of the atmosphere and dump even more CO2 into it for .... what purpose exactly? Perhaps it can launch micro satellites which have a lifetime of a few weeks and are essentially space junk the minute they're launched. Or some idiot space tourists to gormlessly stare at the view.

      1. Anonymous Coward
        Anonymous Coward

        Re: So much potential

        Quite right. As i said to my mate Ugg; 'why invent the wheel? all it's going to do is lead to traffic jams and runaway global warming' and history has proven me right.

      2. jake Silver badge

        Re: So much potential

        Mr Benny, do you know how many tons of CO2 you, personally, are going to produce in your lifetime? Perhaps you could do the Earth a favo(u)r and stop?

        1. Mr Benny

          Re: So much potential

          The all or nothing fallacy is not an argument.

          1. jake Silver badge

            Re: So much potential

            I wouldn't dream of making such an argument.

            Just cut back by 50%, then. We'll wait.

      3. Orv Silver badge

        Re: So much potential

        The engine burns liquid hydrogen, which, since it contains no carbon, cannot emit CO2. The exhaust product would be water vapor. (Water vapor is also a greenhouse gas, but since excess water vapor rains out of the atmosphere it's not a major concern.)

        That's not to say it doesn't have a carbon footprint; actually producing, compressing, and chilling the hydrogen is pretty carbon-intensive with current technology. There's nothing precluding doing it with renewable energy, mind, it's just not currently economically feasible when producing it from natural gas is an option.

        1. streaky Silver badge

          Re: So much potential

          actually producing, compressing, and chilling the hydrogen is pretty carbon-intensive with current technology

          Not really. With *current technology* we can do it for free, the input being water, by-product Oxygen. The fact there hasn't been any investment to scale up isn't the fault of existing technology, it's the fault of governments and people like Elon Musk who are sending the world down the wrong path. We could all be driving HICEVs by now with fairly minimal investment.

          1. Brangdon

            Re: people like Elon Musk who are sending the world down the wrong path

            If by "Musk" you mean SpaceX, they are moving from kerosene to methane, and methane can be made carbon-neutral if anyone actually cares. Which they probably don't as the number of rockets launched is too few to matter.

            1. streaky Silver badge
              Mushroom

              Re: people like Elon Musk who are sending the world down the wrong path

              You can make methane carbon neutral, burning it carbon neutral not so easy.

              Also I meant Tesla obviously but now you mention it, all that NASA research into liquid hydrogen burning in oxygen rocket engines, pissed away. https://www.youtube.com/watch?v=MjQ0j1a9RcA

      4. Bronek Kozicki Silver badge

        Re: So much potential

        It so happens that the only byproduct of burning hydrogen in oxygen is H2O. Taking the space launch industry in this direction would definitely help reducing the CO2 impact it has on the atmosphere.

        1. Orv Silver badge

          Re: So much potential

          It's already pretty common -- the Delta IV Heavy uses LH2 for all stages, for example. Some other boosters do use RP1 (kerosene), especially in the first stage, because it's both easier to handle and more energy-dense by volume. (LH2 is more energy-dense by weight, but bulky.) It's worth noting that countdown aborts and scrubbed launches due to hydrogen leaks are pretty common on Delta IV missions.

        2. Anonymous Coward
          Anonymous Coward

          Re: So much potential

          burning hydrogen in oxygen does only produce steam - H20. Burning Hydrogen in air will also produce NOx - depending on the actual combustion temperatures.

          1. John Smith 19 Gold badge
            Go

            "Burning Hydrogen in air will also produce NOx "

            As part of the LAPCAT project REL developed a new design of combustion injector that is expected to generate 1% of the NOx of existing combustors.

            The SABRE 4 cycle splits the system into 2 separate combustion chambers this is now much more viable.

            1. DJO Silver badge

              Re: "Burning Hydrogen in air will also produce NOx "

              While burning Hydrogen does only produce water you have to get that Hydrogen from somewhere. There are 2 major way to get the stuff:

              1) Electrolysis of water - hugely inefficient and unless the power is from a renewable source will generate lots of CO2

              2) Catalytic breakdown of hot natural gas with superheated steam - this really produces a lot of CO2 and needs a fair amount of power to get it running hot enough.

              There are less polluting ways to get Hydrogen such as biological methods but they are either very small scale or still in the laboratory stage.

              1. Anonymous Coward
                Anonymous Coward

                Re: "Burning Hydrogen in air will also produce NOx "

                "unless the power is from a renewable source will generate lots of CO2".

                I suspect even powering a large fleet of Sabre-engined Skylons would not make a significant uptick in the global production of H2.

                Is this a case of the perfect is the enemy of the good?

    3. anothercynic Silver badge

      Re: So much potential

      It's already proven itself... and some applications of it (in a sense) are already in use. I happen to know several RE engineers and yeah, they're stressed but they are proud as punch about this, as am I. That takes some doing.

  2. Doctor Syntax Silver badge

    It's not clear to me how the excess heat gets dumped so efficiently into already hot gas that the helium becomes supercooled again. That seems to me a far more difficult trick than using cold helium to cool hot gas.

    1. TechnicalBen Silver badge

      IIRC you don't.

      Look up current pre-cooler systems on rocket engines.

    2. Andrew Newstead

      The Helium is cooled by the LH2 fuel that is being fed to the engine at that time, effectively pre-warming the cryogenic fuel before combustion and the heat from the heat exchanger being dumped overboard.

      1. Orv Silver badge

        The trick here being you have to pre-warm the fuel anyway, so using it as a heat sink for the helium precooler coolant kills two birds with one stone.

        Some earlier proposed designs used simpler schemes where the liquid hydrogen was used directly as a coolant. The problem is this causes a lot of materials problems. Steel and some other metals become brittle with prolonged exposure to hydrogen.

        1. steelpillow Silver badge
          Boffin

          After preheating the liquid hydrogen fuel, the helium is then passed through a conventional expansion nozzle to liquefy it, just like any other refrigerator coolant. At least, in principle. The full thermodynamic cycle is really rather complicated.

        2. CrazyOldCatMan Silver badge

          metals become brittle with prolonged exposure to hydrogen

          Indeed. And pretty much everything is porous to hydrogen to some extent or other..

          1. A.P. Veening

            Metals become brittle at extreme low temperatures, whether caused by liquid hydrogen or liquid helium isn't really important.

            And pretty much everything is porous to hydrogen to some extent or other.

            The same goes to a larger extent for helium, that is mono-atomic.

      2. DJO Silver badge

        The Helium is cooled by the LH2 fuel that is being fed to the engine at that time

        I wonder what they used for that in the static test, I'm pretty certain the J79 engine does not burn hydrogen. Perhaps they vented liquid air to cool the Helium refrigerant?

  3. Chris G Silver badge
    Pint

    Amazing

    If one day we could see RAF roundels on a straight to space craft, a la Jet Ace Logan.

    The sooner Reaction Engines can keep most of their development work in the UK the better.

    See icon for the team.

    1. Persona

      Re: Amazing

      Don't hold your breath. It's a fantastic engine concept but its target Skylon space plane sadly stands little chance of taking off from the 5.9km long runway it needs, and putting a payload into orbit. On paper it could put 12.5 tons into LEO with a fuel reserve of 0.5% however like any SSTO spacecraft any additional dry mass that inevitably creeps in during the design and build process directly reduces the payload capacity in a ratio or one to one.

      1. bazza Silver badge

        Re: Amazing

        Exactly how much mass it can launch looks like it won't matter. There's a growing mood for self assembly satellites. Put smaller bits into orbit, have them bolt themselves together. What matters then is speed of repeat launches, where Skylon looks good.

        Doing it this way is attractive, because the cost of an integration facility on earth for an enormous satellite is very expensive. It's much cheaper to have a smaller facility that can handle one sub-sat at a time, you can sub bits of work out more easily, it's appealing because modularity makes design work a hell of a lot easier, etc.

        So, Skylon might not end up being the biggest launcher with the best £/kg, but if customers are saving big time elsewhere and don't need a whole year of SpaceX launches to assemble the spacecraft in orbit (time to operational is also money), it does look quite good.

        1. Persona

          Re: Amazing

          The point is that being SSTO (Single Stage To Orbit) if the inevitable dry mass increases during detailed design and build goes up by just 12.5 tons it will not be able to deliver any payload to orbit. SSTO is not a good solution for our planet.

        2. John Smith 19 Gold badge
          Unhappy

          "There's a growing mood for self assembly satellites. "

          Says who?

          The people pitching one of the 18-40 TSTO VTO ELV's that are desperately scrabbling for market?

          The infrastructure to do that does not actually exist. It'll have the compatibility issues of VHS/Betamax/V2000 multiplied by a 1000.

          Now how will they get that tinkertoy satellite to GEO? Or to escape velocity?

          Skylon's T/O buys you a full size GEO comm sat and the stage to get it there (or to escape velocity, or just below, but with a big payload).

      2. MrXavia

        Think about the other options

        There are issues, and if we compare it to current/future rockets, it probably isn't the way forward for space launches, Methane/Hydrogen rockets are probably the future.

        But as an engine, it is amazing tech and could lead to supersonic, environmentally friendly air travel.

        I'm more excited about that than I am about the space launch capabilities in the near term.

      3. Ian Michael Gumby Silver badge
        Boffin

        @Persona Re: Amazing

        Uhm 6km is ~3.6 miles.

        Of course that's not too long when you consider large transport, heavy lift aircraft could need 8-10K feet or ~1.8 miles.

        So I don't think runway length should be an issue.

      4. John Smith 19 Gold badge
        FAIL

        "On paper it could put 12.5 tons into LEO"

        You're about 1 generation behind the D2. That's 15 tonnes.

        What you don't seem to know about Skylon (because you've just cut-and-pasted a generic SSTO idea perhaps) is it is the only SSTO that offers VTO TSTO payload fraction IE 3-4% of GTOW as payload.

        And the 3000 sec Isp (during air breathing mode, but that's enough) buys it a lot of weight growth in a way rocket based VTOL designs just don't have.

        1. Persona

          Re: "On paper it could put 12.5 tons into LEO"

          My knowledge on Skylon was from reading the 2003 concept paper (which I still have). The mass budget of 12.5 tons came from there (by adding the payload and fuel reserve numbers) so OK it was a while ago so there must be a latter version and it's now 15 tons.

          The ISP of 3000 air breathing is irrelevant. That great ISP helps put the dry mass of the Skylon plus the payload and the 0.5% fuel reserve into LEO. If the dry mass goes up (it will) the payload will go down by the same amount. If you study the mass budget table in the design paper this should be apparent.

          The good news is that now its 15 tons (or 17 tons according to some sources) they have a lot more to play with . The bad news is that Skylon is still just an idea 15+ years later.

          1. John Smith 19 Gold badge
            Unhappy

            "If you study the mass budget table in the design paper this should be apparent."

            Perhaps you should study the bit labeled "Growth margin."?

            Skylon has one.

            Other SSTO concepts don't.

    2. Steve Davies 3 Silver badge

      Re: Amazing

      I'm worried that El Trumpo will declare this testing (in colorado) to be 'In the US National Interest' and declare it US property.

      1. holmegm

        Re: Amazing

        No you aren't.

    3. steelpillow Silver badge

      Re: Amazing

      More likely, hypersonic atmosphere and sub-orbital vehicles will be the first application. Reaction Engines have taken Skylon off their web site.

    4. John Smith 19 Gold badge
      Unhappy

      "..Reaction Engines can keep most of their development work in the UK the better."

      Actually they do.

      The test facility is in the US.

      The HX was designed and built in the UK.

      Which AFAIK is where the design and mfg operation is planning to stay.

      BTW AFAIK this is the first new high temp,high speed airflow test site in the US for decades. I think they're hoping it will raise some fees testing out other peoples idea for hypersonic flight.

  4. John Brown (no body) Silver badge

    Saw this a earlier this morning on the Beeb site

    ...but then I made the mistake of reading through HYS. OMG there are some luddites out there!!!

    El Reg comments, even Jake, Bob and AMFM1, are sane by comparison! :-)

    Huge thumbs up for all at REL for this next stage. I hope I'm still around to see SABRE power the first Dan Dare style space plane.

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