back to article ESA builds air-breathing engine that works in space

The European Space Agency has hailed the successful test of an air-breathing engine that works in space. The engines don’t need the oxygen found in air to burn. Instead, as the ESA has explained here, the idea is to collect air, compress it, give it a charge and then squirt it out to provide thrust. The engine has no moving …

    1. James 51
      Joke

      I was thinking more of how they could move from being proof of concepts and a way to get students interested in space to a workhorse platform that can do interesting or helpful stuff faster, cheaper and easier than higher orbit sats but I should have figured out el reg regulars would find a way to view it from another angle.

      1. Anonymous Coward
        Anonymous Coward

        "[...] I should have figured out el reg regulars would find a way to view it from another angle."

        Think of it as a game of political correctness or chess. You think twice about what you have done to see if you have left anyone room to manoeuvre**. Then you decide if you want to be amused by the exploits - or you hope someone will make a move for which you have a counter already prepared.

        Lateral thinking is an ability to be prized in IT. Bangor University Electronic Engineering department ran degree applicants through a few tests - and that was a sought after trait. A question I remember was simply "what is a U2". To which there were several answers at that time.***

        **correct spelling - unlike the lorry warning sign that Waitrose put outside some store delivery bays.

        ***battery (now D type); submarine, spy plane. The pop group didn't come along until later.

  1. Anonymous Coward
    Anonymous Coward

    Accelerating the wrong way ?

    I am not a rocket science, but in the diagram the direction of acceleration is in the opposite direction to its travel, which to a layman like me means the engine is slowing it down ?

    1. frank ly

      Re: Accelerating the wrong way ?

      I'm sure that represents acceleration of the gathered propellant gas. Issac Newton will take care of the rest.

      1. CrazyOldCatMan

        Re: Accelerating the wrong way ?

        Issac Newton will take care of the rest.

        By having it fall on his head?

    2. hplasm
      Coat

      Re: Accelerating the wrong way ?

      "I am not a rocket science."

      You are a brain surgery and I claim my £5!

    3. bombastic bob Silver badge
      Boffin

      Re: Accelerating the wrong way ?

      "the engine is slowing it down"

      OK - I do a mini-simulation in my head, and I see air going into some kind of 'scoop' device, like what you might see on a ramjet [only a "space" version], and I consider a few things that aerodynamics might cause some trouble with:

      a) when the air enters the scoop, how does it get collected exactly? [you need some kind of compressor pump I'd think]

      b) while air is collecting for a compressor pump intake cycle, wouldn't it build up enough pressure to exert an impulse on the satellite, causing it to slow down just a bit more?

      c) is the electrostatic acceleration going to be ENOUGH more than the (effective) drag caused by the intake scoop going to be enough to overcome the additional drag of the satellite itself against the atmosphere? [this includes the solar panels, too, which just might not be all that streamlined]

      I imagine the rocket scientists have thought all this out. Hopefully I didn't just poop their party.

      1. jake Silver badge

        Re: Accelerating the wrong way ?

        Bob, do you even know how a ramjet works? Compression is provided by velocity. That's kind of the point of the contraption ...

  2. Uncle Slacky Silver badge
    Boffin

    Biefeld-Brown effect (AKA "lifters", "ionocraft")

    Nice to finally see electrokinetic (or "ion wind") effects finally being exploited in space. As a former participant in BAE's Project Greenglow I was aware of attempts to interest Surrey Satellite Technology in this idea more than 15 years ago.

    https://en.wikipedia.org/wiki/Biefeld%E2%80%93Brown_effect

    https://en.wikipedia.org/wiki/Electrohydrodynamics

    https://en.wikipedia.org/wiki/Ionocraft

  3. Anonymous Coward
    Anonymous Coward

    Interesting airflow

    The air ahead of the engine curves its way to the inlet - anticipating the arrival of the engine. That's a neat trick.

    1. SkippyBing

      Re: Interesting airflow

      Would that be because the engine is causing a localised area of low pressure? I know conventional jet engines, and wings to some extent, have that effect but I'm not sure if that's directly comparable to this tech.

      1. Steve the Cynic

        Re: Interesting airflow

        Conventional jet engines have heavy-duty compressor turbines at the front, although when flying at speed, the compressor is mostly just compressing further an already compressed stream. (Compressed by intake geometry, that is.) This thing is more like a ramjet, in that it has no turbines to compress the incoming flow, and relies entirely on the intake geometry to do so.

        Note: that's why ramjets don't work at airspeeds below about Mach 0.5, of course. They rely on the air being, well, rammed in by the airspeed.

  4. Andy The Hat Silver badge

    Not a new idea ...

    didn't I have the ability to fuel harvest in Elite?

    1. jake Silver badge

      Re: Not a new idea ...

      See NASA's proposed ionospheric ramjet from 1958. (warning: PDF)

      1. John Smith 19 Gold badge
        Unhappy

        Ionospheric ramjet...

        Yes that would pretty much describe it.

        The trouble with this tech is

        a) Who has sats that need to keep station around this height

        b) Who can afford the development budget for them.

        Historically I think most of the people in a) don't have the money for b).

        Hence the 60 year delay in getting it into a lab test.

        1. Pen-y-gors Silver badge

          Re: Ionospheric ramjet...

          @John Smith 19

          Historically

          a) No-one

          b) No-one

          Now

          a) Elon Musk

          b) Elon Musk

        2. JeffyPoooh
          Pint

          Re: Ionospheric ramjet...

          We humans used to use the ionosphere for International Shortwave Broadcasting. It was quite lovely.

          Now it's all crap.

          So go ahead, Eat the Ionosphere™.

        3. Doctor Syntax Silver badge

          Re: Ionospheric ramjet...

          "a) Who has sats that need to keep station around this height"

          Without the ability to sustain them at that height there'd be no point in even considering something that would need it.

          1. Julz Silver badge

            Re: Ionospheric ramjet...

            Imagery sats.

      2. Jan 0 Silver badge

        Re: Not a new idea ...

        How nice to see a plain text document! Just why did we think that documents like this need "word processing"? Three cheers for the typewriter!

        1. jake Silver badge

          Re: Not a new idea ...

          That wasn't typewritten. It was written out longhand, and then hand set with lead type. Not many typewriters with the characters in Appendix A ...

          Mental note: drop Knuth an email, thanking him again for TeX before it's too late.

    2. Cuddles Silver badge

      Re: Not a new idea ...

      "didn't I have the ability to fuel harvest in Elite?"

      Not the same thing. Elite just allowed you to harvest fuel and store it until you needed it. This idea is instead a kind of ramjet, where the fuel is scooped straight into the engine and used immediately. It's still not a new idea, since ramjets have been around for a while, but this is the first time the principle has been applied to an ion engine rather than an actual jet.

  5. Anonymous Coward
    Anonymous Coward

    I'll get excited when we have a working warp drive, come on Zefram Cochrane pull your finger out.

  6. smartermind

    Lack of moving parts

    Would't the spacecraft need moving parts to suck in the air in the depleted atmosphere?

    Also wouldn't the drag in even a depleted atmosphere negate the acceleration from the ionized air?

    1. Rich 11 Silver badge

      Re: Lack of moving parts

      Also wouldn't the drag in even a depleted atmosphere negate the acceleration from the ionized air?

      That would depend primarily on how much energy you have available to ionise and accelerate the collected air. I expect they've done the calculations, what with them being, you know, fucking rocket scientists.

    2. aks

      Re: Lack of moving parts

      Does the satellite count as a moving part? ;)

      1. Anonymous Coward
        Go

        Re: Lack of moving parts

        >Does the satellite count as a moving part? ;)

        Not if you are the observer stood on the satellite, everything is relative.

        1. CrazyOldCatMan

          Re: Lack of moving parts

          everything is relative

          Parents especially so.

    3. Anonymous Coward
      Anonymous Coward

      Re: Lack of moving parts

      A turbomolecular vacuum pump uses a high speed turbine to sweep gas molecules towards the high pressure side. They operate around the 1 x 10-8 atm level and the thrust would be equivalent to how much more 'push' (increase in velocity) you could give the molecule

      Ionization gives much higher velocities to the gas, and since thrust is mass x velocity, more effective.

    4. John Brown (no body) Silver badge

      Re: Lack of moving parts

      "Would't the spacecraft need moving parts to suck in the air in the depleted atmosphere?"

      Depends on which way the wind is blowing and how fast. Orbital velocity is a tad higher than even a Tesla in Ludicrous mode. The ISS is travelling at about 17,150mph and the lower the orbit, the higher the velocity.

  7. Alister

    Does this work in a similar way to SABRE?

    Ah, after reading how SABRE works, the answer is no.

    As you were...

    1. detuur

      I'm still upset SABRE isn't a large priority to ESA. Could revolutionise cheap launch platforms but instead being given a "fusion never" budget.

    2. CrazyOldCatMan

      similar way to SABRE

      What? They sit in a big datacentre in Tulsa?

      (Old airline reservation programmer joke. It wasn't funny then either)

  8. caffeine addict

    Imagine speccing that "wind tunnel".

    We need you to build a vacuum chamber for us.

    "Okay..."

    Big enough to put a satellite in.

    "Okay"

    And then, and you're going to love this, we need you to turn it into a wind tunnel.

    "Oka- what?"

    We need you to make it a really powerful wind tunnel too. One to simulate 7.8km/s."

    "Back up. A wind tunnel in a vacuum?"

    Yeah. Well, that's okay because we both know you engineers can't make a pure vacuum. We need space levels of vacuum. And we need it to move really fast.

    "Hey! We can make a vacuum! But you want your vacuum to move really fast? There's nothing there to move."

    We know. That's why you'll need a really big fan. That nothing has to do 7.8km/s. Then we're going to compress it, ionise it, and see if it goes forwards.

    "You want to compress high speed nothing, fiddle with it, and see if it will give you forward thrust into a 7.8km/s headwind of nothing?"

    Yep.

    It's at this point half the engineers quit to go become landscape gardeners and the other half get a slightly crazed look in their eyes and start muttering into their beards.

    1. I ain't Spartacus Gold badge
      Happy

      Re: Imagine speccing that "wind tunnel".

      And the real landscape gardeners have to keep shouting at the engineers-turned-landscape gardners, "Green side up!"

      "And stop laying that turf with a bloody hammer!"

      1. Anonymous Coward
        Anonymous Coward

        Re: Imagine speccing that "wind tunnel".

        ""And stop laying that turf with a bloody hammer!"

        Tamping the edge joins with a plank and a big hammer?

      2. CrazyOldCatMan

        Re: Imagine speccing that "wind tunnel".

        "And stop laying that turf with a bloody hammer!"

        I'm assured by my builder friends that *everything* can be done with a hammer. Apart from the jobs that need a bigger hammer.

    2. keith_w Bronze badge

      Re: Imagine speccing that "wind tunnel".

      Sounds like a job for the PFY

      1. I ain't Spartacus Gold badge
        Devil

        Re: Imagine speccing that "wind tunnel".

        A chickpea and baked bean vindaloo, 15 pints of real ale, and a kebab chaser should do it.

        1. CrazyOldCatMan

          Re: Imagine speccing that "wind tunnel".

          A chickpea and baked bean vindaloo, 15 pints of real ale, and a kebab chaser should do it.

          Well - that'll do nicely for producing the wind tunnel part..

    3. jake Silver badge

      Re: Imagine speccing that "wind tunnel".

      Sorry to burst your amusement ... but look up "high-altitude wind tunnels". NASA has a rather nice one located in Silly Con Valley that can easily imitate LEO pressures and velocities.

    4. John Brown (no body) Silver badge
      Pint

      Re: Imagine speccing that "wind tunnel".

      "It's at this point half the engineers quit to go become landscape gardeners and the other half get a slightly crazed look in their eyes and start muttering into their beards."

      Nicely done. I "heard" that in the voice of Bob Newhart. Have a pint on me.

  9. Milton

    Look on the bright side ...

    ... it isn't a microwave-energised reactionless perpetual motion thruster powered by a comical failure to understand vector math.

    1. Gordon 10 Silver badge
      Boffin

      Re: Look on the bright side ...

      Which if I recall correctly has actually been show to work experimentally or at least looks promising?

      Yae cannae change the laws of physics Jim! Except when they are wrong or poorly understood.

      1. JeffyPoooh
        Pint

        Re: Look on the bright side ...

        Gordon noted that EM Thrust "...actually been show to work..."

        More likely shown a subtle lab error.

        Remember the "faster than light particles", a.k.a. Loose GPS cable? Mistakes happen.

        1. Anonymous Coward
          Anonymous Coward

          Re: Look on the bright side ...

          >Remember the "faster than light particles", a.k.a. Loose GPS cable? Mistakes happen.

          And Fleischmann–Pons cold fusion reactor, it was subsequently found to be the effect of one of the experimenters hard boiled lunch eggs had dropped into the chamber which promptly went critical on removal.

          1. Baldrickk

            Re: Look on the bright side ...

            I know the story about the experiments, but what is this about an egg? link pls

            1. Uncle Slacky Silver badge
              Boffin

              Re: Look on the bright side ...

              I don't know anything about an egg, but research is still ongoing, they just don't call it "fusion" any more - it's now "Low Energy Nuclear Reactions": http://lenr-canr.org/

              1. Alan Brown Silver badge

                Re: Look on the bright side ...

                Nuclear fusion reactions are easy to produce. The Farnsworth Fusor is one example.

                The hard part is getting more energy out of the building than went into the building.

                They've only just managed to break even on energy in vs generated in the chamber after 40+ years of trying, let alone getting a profit on energy out of the chamber. As any electrical engineer will tell you, until you get over unity on the entire site you don't have a viable power source.

  10. steelpillow Silver badge

    sustainable?

    A problem to be overcome is the size of the solar panels. Add them and your aerodynamic drag increases, needing more thrust to stay in orbit, needing more solar panels, creating more drag...

    Will be interesting to see if it is practicable to break this vicious circle.

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