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. Anonymous Coward
    Anonymous Coward

    Typo

    "The engine has no moving parts and that’s needed to power the engine is electricity."

    should be:

    "The engine has no moving parts and all that is needed to power the engine is electricity."

    Seriously, who proof reads at Reg Vulture Relocated Rotting Corpse Central?

    1. A Non e-mouse Silver badge

      Re: Typo

      I wouldn't bother applying for the job as you missed the "Tips and corrections" link that's at the bottom of every story.

      1. smartermind

        Re: Typo

        If the coward used the corrections link, we wouldn't, necessarily, know about it and be able to add our invaluable input!

      2. iron Silver badge

        @A Non e-mouse

        The email link for corrections? If you use webmail or don't have an email client set up for some other reason it is completely useless. It's long past time El Reg had a convenient web form for corrections rather than relying on email.

        1. DuncanT

          Re: @A Non e-mouse

          Or you could try setting up your machine properly to handle a very basic href standard.

        2. Mage Silver badge

          Re:don't have an email client set up for some other reason it is completely useless

          I had real email on my phone in 2001. I don't bother now as I don't go out.

          Sure 1/2 the people reading are probably in offices during day?

        3. CrazyOldCatMan Silver badge

          Re: @A Non e-mouse

          The email link for corrections? If you use webmail or don't have an email client set up for some other reason it is completely useless

          If only computer came with the ability to copy a bit of text from one browser window to another eh? That would mean we could do a whole lot more!

          There - can you see my level of sympathy? It's not only very, very small, it's also very, very, very far away...

      3. Anonymous Coward
        Anonymous Coward

        Re: Typo

        > you missed the "Tips and corrections" link

        You mean the mailto: link? If there was a proper webform that was quick and convenient, I'd happily use it. Having to disclose my email address or go through the faff of logging into a throwaway one to correct someone's spelling mistakes? I don't think so.

        1. jake Silver badge

          Re: Typo

          Sending email is DIFFICULT??? Methinks ElReg might be too advanced for you. Perhaps try another redtop?

          And BTW, Mr/s AC, ElReg already has your email address. Remember, that one you used to sign up with? The one that all your posts are linked to? Hint: eyeball your posting history. Not all that anonymous, are you?

          1. Anonymous Coward
            Anonymous Coward

            Re: Typo

            > Mr/s AC, ElReg already has your email address.

            The throwaway email address that I used to sign up here like twenty years ago does not even point to an existing domain. I am not sure if it ever did.

            Quite apart from the loss of privacy, I would hate to deal with all the spam that results when people give their actual email address(es) to world + dog.

            1. jake Silver badge

              Re: Typo

              So you admit you falsified your ElReg registration info? Are you certain you want to do that? After all, it's been your handle "for like 20 years" (yeah, sure, right). I'd hate to see you lose it.

              You also admit that you use email addresses that are not yours? There's a word for that.

              How on earth do you equate using a proper email address to register here with "giving your email addres(es) to world+dog"? Do you really think ElReg is likely to sell your address to spammers? Or are you so paranoid that not even your DearOldMum knows your email address? Because I guarantee that ElReg is a hell of a lot less likely to be compromised than she is. Kinda makes email pretty useless for you, no? So you may as well use the real thing, useless as it is ...

              Your privacy in this context is totally meaningless outside your personal paranoia.

              1. CrazyOldCatMan Silver badge

                Re: Typo

                Do you really think ElReg is likely to sell your address to spammers

                .. which they don't. Or, at least, I've never had any spam addressed to the variant I use for El Reg..

                Your privacy in this context is totally meaningless outside your personal paranoia.

                [Potstirring mode=On]

                Just because you are paranoid doesn't mean they are not out to get you..

                [/PSM=Off]

            2. gotes

              Re: Typo

              You could send an e-mail using a completely fabricated from: address if you want, all you need is an SMTP server.

              Alternatively publicly deride the author for making a simple error.

        2. Mage Silver badge

          Re: disclose my email address

          Didn't you do that ANYWAY, to be a commentard?

        3. CrazyOldCatMan Silver badge

          Re: Typo

          webform that was quick and convenient, I'd happily use it. Having to disclose my email address

          .. which you must have done in order to get an El Reg login..

      4. eldakka Silver badge

        Re: Typo

        The tips and corrections link is a mailto: link, which isn't much help when you don't have an email client installed.

        And I'll admit to being too lazy to go through the rigmarole of logging into webmail when I can just post it as a comment.

        The reg would be better off making it a form that, it they really want an email, sends an email.

        1. CrazyOldCatMan Silver badge

          Re: Typo

          The reg would be better off making it a form that

          .. can be abused by every spam engine out there?

          I have one website that has a feedback form. Despite the fact that it goes no-where else other than webmaster@, it gets tons of autofilled spam.

          It also regularly gets a whole SMTP conversation (albeit one-sided) where scum^W spammers are trying to use it as if it was an open relay..

          1. MrKrotos

            Re: Typo

            "I have one website that has a feedback form. Despite the fact that it goes no-where else other than webmaster@, it gets tons of autofilled spam."

            Your doing it wrong then!

            1. jake Silver badge

              Re: Typo

              Blaming the victim, MrKrotos?

    2. Anonymous Coward
      Anonymous Coward

      Re: Typo

      The "that's" is more probably a single letter typo of "what's".

      "The engine has no moving parts and what's needed to power the engine is electricity."

    3. Anonymous Coward
      Anonymous Coward

      Re: Typo

      The sort of complaints we'd have to get used to if Jacob Rees-Mogg was to become Prime Minister (please no), where tedious (Mogg like-minded) people get so wrapped up in minute detail that nothing ever gets done.

      It's a great article, see it for what it is.

      (You could be having a field day over at the Daily Mail. Maybe, head over there, they describe Scottish people as "English roses")

      1. Simon Harris Silver badge

        Re: Typo

        The sort of complaints we'd have to get used to if Jacob Rees-Mogg was to become Prime Minister

        It's just as well it's not Boris Johnson, or we'd have to have the typos corrected in Latin.

        1. Anonymous Coward
          Anonymous Coward

          Re: Typo

          It's just as well it's not Boris Johnson, or we'd have to have the typos corrected in Latin.

          Mutatis mutandis

          1. CrazyOldCatMan Silver badge

            Re: Typo

            Mutatis mutandis

            BoJo is a mutated mustard?

      2. Jemma Silver badge

        Re: Typo

        Tis better than what they used to call them, forsooth - to whit "moving targets"

        That said the next person who complains on a forum about their cars expensive break job, I will happily chase down with a Ricin laced crossbow.

        1. Pen-y-gors Silver badge

          Re: Typo

          @Jemma

          cars expensive break job

          Hey, if you break your Ferrari by wrapping it round a tree, it is a VERY expensive job!

        2. Anonymous Coward
          Anonymous Coward

          Re: Typo

          You want to lace up a crossbow? That's some weird Tory MP level stuff right there....

          1. CrazyOldCatMan Silver badge

            Re: Typo

            That's some weird Tory MP level stuff right there.

            Oh I dunno - the old time Liberal party was partial to a bit of that too.

            Err.. allegedly.

        3. jake Silver badge

          Re: Typo

          As long as it's just the crossbow, and you're the one handling it. The bolts, on the other hand ...

          The gripping hand wonders if lacing a crossbow is anything like lacing a wheel?

        4. CrazyOldCatMan Silver badge
          Coat

          Re: Typo

          I will happily chase down with a Ricin laced crossbow

          It's probably better to lace the bolts with Ricin..

          OK, OK, I'm just leaving. Mine's the coat with the built-in leather plates and the chain coif attached.

      3. Anonymous Coward
        Anonymous Coward

        Re: Typo

        And if Jeremy Corbyn was Prime Minister then you could denounce people who make complaints you don't like and have them sent to the gulag to be worked to death.

        But I prefer to keep childish and irrelevant political commentary in the Guardian where it belongs.

        1. MyffyW Silver badge

          Re: Typo

          Oi! I rather like the Grauniad.

          1. Mage Silver badge

            Re: Grauniad

            You mean the Gridion. The Truth will make you fret.

      4. Anonymous Coward
        Anonymous Coward

        Re: Typo

        > It's a great article, see it for what it is.

        I beg to differ. The subject of the article may be great. The article itself is just a quick (and typoed) rewording of the ESA's own press release. This article's only plus is that it provides a link to that.

    4. Adam Jarvis

      Elon Musk's plans for a low orbit, low latency network of satellites.

      Elon Musk's plans for a low orbit, low latency cluster/network of satellites providing Internet capability, is looking rather more feasible and manageable. This would give those satellites a much longer working life.

      Maybe he knew more than he was letting on when he announced it.

      1. Stu Mac

        Re: Elon Musk's plans for a low orbit, low latency network of satellites.

        A global internet free of ICAAN, censorship or the copytheft monopolists?

      2. Mage Silver badge

        Re: Elon Musk's plans for a low orbit, low latency network of satellites.

        He's the third organisation with the idea. Work started already.

        The problem is that while it solves the latency issue of Ka-Sat (with its 82 spots approx), it doesn't give very good capacity.

        Good coverage doesn't mean good speed.

    5. AceRimmer1980
      Coat

      Re: Typo

      Bussard central, shurely?

  2. MacroRodent Silver badge

    GOCE

    >ESA’s GOCE gravity-mapping mission, but it carried 40kg of Xenon gas to provide it with thrust so it could change altitude when its orbit became low.

    Actually it ran the ion thruster all the time, to keep it orbiting smoothly, despite the air resistance.

    1. John Smith 19 Gold badge
      Boffin

      The concept’s been used before by..GOCE..but it carried 40kg of Xenon gas

      That's called an ion thruster. Lots of those have been used.

      This uses the ambient "atmosphere" (although it's roughly < 1/32 Sea Level pressure).

      This is (loosely) an "Ion ramjet" rather than an "Ion rocket"

      So yes that is pretty impressive as it's one of the first (the first?) ever demonstrated.

      1. JeffyPoooh Silver badge
        Pint

        "...roughly < 1/32 Sea Level pressure...".

        JS19 suggested that the environment under discussion was "...roughly < 1/32 Sea Level pressure...".

        At orbital velocity, roughly 1/32 Atmosphere would cause any spacecraft to be quickly incinerated. This is one reason why there are not very many satellites orbiting at 80,000 feet above the Earth.

        1. Bronek Kozicki Silver badge
          Pint

          Re: "...roughly < 1/32 Sea Level pressure...".

          I would just say that "roughly <" was a tiny understatement.

        2. John Smith 19 Gold badge
          Unhappy

          At orbital velocity, roughly 1/32 Atmosphere would cause any spacecraft

          Ooops.

          Well that's what happens when you use the rule of thumb of air pressure halving every 5.6Km.

          In fact https://www.avs.org/AVS/files/c7/c7edaedb-95b2-438f-adfb-36de54f87b9e.pdf

          Suggests its more like 72 millionths of a Psi.

  3. James 51 Silver badge

    depends on how this tech scales but you could find more sats lasting longer in low orbit. More accurate GPS, sat phone prices (both handset amd air time) might drop to sane levels (imagine access outside everywhere in the world and pico cells for inside). Cube sats could be revolutionised.

    1. Anonymous Coward Silver badge
      Joke

      "Cube sats could be revolutionised."

      Would that make them sphere sats?

      1. jake Silver badge

        Don't be such a square, man.

      2. James 51 Silver badge

        @AC all I need is a lightsabre and a helmet with a broken visor.

      3. TRT Silver badge

        Wouldn't that make them sphere sats?

        Cubes vs spheres? Sounds familiar.

        1. Pedigree-Pete Bronze badge
          Thumb Up

          Re: Cubes vs spheres? Sounds familiar.

          Thank you TRT. Nice to hear Windsor Davis again.

      4. Sgt_Oddball Silver badge

        Does that mean we'd see them on the telly?

    2. James 51 Silver badge
      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.

  4. 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 Silver badge

      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 Silver badge

        Re: Accelerating the wrong way ?

        Issac Newton will take care of the rest.

        By having it fall on his head?

    2. hplasm Silver badge
      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 ...

  5. 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

  6. 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 Silver badge

      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 Silver badge

        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.

  7. 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 Silver badge
          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

            Re: Ionospheric ramjet...

            Imagery sats.

      2. Jan 0

        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.

  8. Anonymous Coward
    Anonymous Coward

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

  9. 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 Silver badge

          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.

  10. Alister Silver badge

    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 Silver badge

      similar way to SABRE

      What? They sit in a big datacentre in Tulsa?

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

  11. caffeine addict Silver badge

    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 Silver badge

        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

      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 Silver badge

          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.

  12. Milton Silver badge

    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 Silver badge
        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 Silver badge

            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.

  13. 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.

    1. Gordon 10 Silver badge
      Coat

      Re: sustainable?

      Use them as wings! Simples.

    2. caffeine addict Silver badge

      Re: sustainable?

      Presumably you don't need to fire this kind of thing all the time, in which case you could use relatively small solar panels that charge a battery then burst energy into the engine. If it's infrequent enough, you could angle the panels inline with the flow and accept that you would get a lot of suboptimal charging.

    3. Rich 11 Silver badge

      Re: sustainable?

      Maybe the panels need to be shaped like an aerofoil and given the right angle of attack...

    4. Duncan Macdonald Silver badge

      Re: sustainable? - Air catchers ?

      If the solar arrays are in front of the engine and angled correctly they could feed more air into the engine possibly doubling the thrust for a given size of engine.

  14. JeffyPoooh Silver badge
    Pint

    Should use Space Junk as propellant

    Grab bits and pieces of Space Junk, grind them up and fire them out the back. Aim them so that they'll hit the atmosphere. Win-win.

    1. This post has been deleted by its author

  15. Pen-y-gors Silver badge

    Song of the lonely (air-breathing) cubesat

    It's cold outside, there's no kind of atmosphere

    I'm all alone, more or less

    Let me fly far away from here

    Fun, fun, fun in the sun, sun, sun

  16. unwarranted triumphalism Bronze badge

    This neatly exposes the lie of so-called 'space'. Another defeat for the scientards.

    1. imanidiot Silver badge

      *Not sure if serious and/or sarcastic*

      1. John Brown (no body) Silver badge

        "*Not sure if serious and/or sarcastic*"

        Judging by recent posting history, he's serious.

        1. jake Silver badge

          Either painfully ignorant or trolling. Trolls are lucid occasionally. Hell, even amfM is lucid occasionally!

          1. amanfromMars 1 Silver badge

            Re Painfully Ignorant Trolling .... in the Advancement of Arrogance. Surely a Sin Anywhere

            Either painfully ignorant or trolling. Trolls are lucid occasionally. Hell, even amfM is lucid occasionally! .... jake

            jake, hi, how's it hanging?

            If one be truthfully advised but choose not to accept that amfM is always default lucid, would painfully ignorant disagreeable trolls be created and identify themselves with commentary to the contrary on matters then which are clearly misunderstood or not more widely known of yet .... yet to be discovered/revealed/uncovered/demystified/realised/presented?

            And would such Presentations and Realisations be of the Future in the Here and Now, or in the Future, and be both such Presentations and Realisations from the Future with no baggage or hindrance from the Past to cast Shadows of Doubt on Current Augmented Virtualised Reality Direction Flows?

            From where and how do you imagine the Future arrives? Created out of nothing nowhere and phormed by no one terrestrial on Earth?

            That would then surely suggest at least two possible options, which are not themselves mutually exclusive, for either along with the other is just as likely as not the Actuality and AI Singularity. Your Future is an Alien Construct and/or a Product and Result of Communication with Global Operating Devices in Command and Control of Advanced IntelAIgent Media Channels with COSMIC Classified Chunnels Securing Secret Services and Servers.

            Earthlings/Humans are defaulted/programmed/brainwashed to believe what Media tells/shows them, are they not? Quite why Media would not then Create and Paint a More Perfect Beta Picture for Population and Enjoyment is then certainly because of a catastrophic lack of in-house intelligence.

            The Posit here clearly is ..... Greater Beta Intelligence for More Perfect Picture Painting with Advanced IntelAIgents is readily available for Co-Opting from elsewhere.

            I trust on this occasion there is no ambiguity present and everything is pretty lucid.

            1. This post has been deleted by its author

            2. Anonymous Coward
              Anonymous Coward

              Re: Re Painfully Ignorant Trolling .... in the Advancement of Arrogance. Surely a Sin Anywhere

              Reveal? Uncover?,'Tis shows neither love, nor LOVE, and is equal to downshift oneself from the Cards to mere Players.

              1. amanfromMars 1 Silver badge

                Re: Re Painfully Ignorant Trolling .... in the Advancement of Arrogance. Surely a Sin Anywhere

                Howdy, Anonymous Coward,

                Here is a small taster and precursor of what is to be presented for discovery.

                Regarding any Reveal and/or Uncovering of State and Non Stated Quantum Communications Secrets and Prime Cards to be Played in a Greater IntelAIgent Game, is IT and AI Always Ably Protected and Preserved and Reserved for SMARTR Key Players to Use with Impunity, whenever the Tales Told and Enabled and Easily Proven to be True are more widely dismissed and generally treated as Unbelievable ..... just too fantastic to believe is so simply real ...... as may well be the case for many travelling and pausing for thought and commentary through here.

      2. CrazyOldCatMan Silver badge

        *Not sure if serious and/or sarcastic*

        Or, using Occams Razor, just a somewhat ineffectual troll.

        1. Pen-y-gors Silver badge

          *Not sure if serious and/or sarcastic*

          Or, using Occams Razor, just a somewhat ineffectual troll.

          but, to be fair, a pretty dedicated one if he gets to 'Bronze vulture' status

      3. unwarranted triumphalism Bronze badge

        Username checks out, as they sat on Reddit.

    2. Anonymous Coward
      Anonymous Coward

      "This neatly exposes the lie of so-called 'space'."

      What lie? The space is that which is not occupied by substantial bodies like stars, planets, asteroids, and comets. Now if you had said "vacuum of space" - then you would have possibly been on safer ground. However a vacuum vacated by gases is always a relative pressure - and does not signify a (probably hypothetical) total vacuum.

      I suspect that if you lower the pressure far enough inside any container then its surface molecules will start to escape to occupy that space. That's why you can't make a decent cup of tea on a high mountain - the water boils at too low a temperature at the lower air pressure.

      1. Alan Brown Silver badge

        "vacuum of space"

        Which one would that be?

        A vacuum is generally regarded as starting when at the level where air molecules stop colliding with each other but that's still a few million per cubic metre.

        The one at ISS altitudes is far better than _anything_ we can produce on the ground (and yet atmospheric drag is a substantial problem)

        The one at GEO altitudes is a bit better than that (Earth's atmosphere is generally regarded as existing out to around 1000km, despite being more-or-less vacuum above the Karman line.)

        The one in "interplanetery" space is a bit better still, but it's still inside the sun's atmopshere by some measurements.

  17. Alan Brown Silver badge

    Dear Reaction Engines,

    Thank you for your comments and input over the last 30 years. Your services are no longer required.

    ESA.

    1. imanidiot Silver badge

      Re: Dear Reaction Engines,

      Building an engine that can keep a craft ALREADY moving at 7 km/s at that speed in something resembling an atmosphere and building an engine that can accelerate a craft from 0 to 7 km/s is quite a bit different.

  18. Martin Budden

    Aircraft

    So technically it will be an aircraft flying at very very high altitude, not a satellite in orbit. Right?

    1. jake Silver badge

      Re: Aircraft

      By international convention, the Kármán line (100km above sea level) marks the difference between "atmosphere" and "space" for this kind of thing.

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon

Biting the hand that feeds IT © 1998–2019