back to article Boffins demo self-eating rocket engine in Scotland

The concept of a self-eating rocket is rearing its head once again as engineers showcase their work at the AIAA SciTech Forum. Autophage engines – where the rocket effectively consumes itself – were first proposed and patented in 1938. However, it took until 2018 before boffins managed to design and fire one in a controlled …

  1. RockBurner

    Pedant? moi?

    I'm assuming that this sentence :

    "Bzdyk says us the team does intend to scale things up too far"

    is supposed to read:

    "Bzdyk says us the team does not intend to scale things up too far".

    I do find this grammatical error curious: it seems to happen more and more in general life (news reports, social media posts etc etc) and I can't fathom where it comes from. Missing out a negative completely changes the meaning of a sentence. In this case admittedly it simply makes the sentence difficult to parse, but often the omitted negative completely changes the meaning that the writer is attempting to convey.

    1. thosrtanner

      Re: Pedant? moi?

      Not sure what the 'us' is doing in there either. It just adds to the confusion. Possibly should be a 'that'.

      1. David 132 Silver badge

        Re: Pedant? moi?

        I’ve just read the article and evidently it’s now been fixed.

        By the way, from personal experience I can tell you that the Reg team prefer corrections to be sent via the link (at the top of each comments page) - and they’ve been known to get mildly acerbic if this process isn’t followed.

        1. RockBurner

          Re: Pedant? moi?

          I'm aware, I do think the concept merits further discussion though.

        2. Santa from Exeter

          Re: Pedant? moi?

          They then make the correction silently, and don't let on who informed them of their error. I recently corrected a factual. error in a piece and it just changed with no acknowledgement (not even a 'thanks' e-mail reply).

        3. imanidiot Silver badge

          Re: Pedant? moi?

          They can get as acerbic as they want, I ain't firing up the email and typing all sorts of stuff to show which is the article in question and make it a proper email, as I would be doing if I were to make an email. That corrections link should go to a simple web form that is automatically linked to the right article. I am not going to spend more than a dozen or so seconds caring about poor writing enough to make a correction. Writing an email is too much faff. So if I see a correction is needed, they can get it in the form of a reaction post or not at all as far as I care.

    2. usbac Silver badge

      Re: Pedant? moi?

      The problem is that quality control for EVERYTHING is becoming a thing of the past. It doesn't matter if it's software, airliners, or journalism, nothing is being checked for quality anymore.

      My first instinct was that it is a cost thing, but I think the public is just starting to accept poor quality everywhere now. The more accessible everything is, the lower the quality of the output.

      Take for example video/film production. It used to be that it took a team of professionals with expensive equipment to make a film or to shoot a video. Now everyone has a Youtube channel with highly variable production quality (it seems that nobody can get their audio levels right).

      Newspapers used to send trained photographers out with reporters to cover stories, now the reporters are told "to just use your phone". An f'ing phone! Not even a proper camera!

      Publishing a book used to require a publisher and a professional editor. Now anyone can self-publish. Typos, bad grammar , and all.

      The list could go on and on. The threshold for "good enough" is getting lower every day. It seems that British Leyland was just ahead of their time...

      1. Grey_Kiwi

        Re: Pedant? moi?

        "It seems that British Leyland was just ahead of their time."

        Well done, sir!

        Unfortunately this comment will be lost on most of the readership, even the UK portion

        1. Blue Pumpkin

          Re: Pedant? moi?

          The work of a maestro ….

        2. EBG

          Re: Pedant? moi?

          You had to be there.

      2. Throatwarbler Mangrove Silver badge

        Re: Pedant? moi?

        It all started with the Unix way of doing things and has only gotten worse.

      3. Anonymous Coward
        Anonymous Coward

        Re: Pedant? moi?

        Yes, I challenged an acquaintance's poor spelling and grammar once, and her response was "who cares? I got my point across"

        I replied "yes, and you looked like an illiterate dumbass, too... doesn't that bother you?"

        Apparently it doesn't.

      4. jollyboyspecial Silver badge

        Re: Pedant? moi?

        "Newspapers used to send trained photographers out with reporters to cover stories, now the reporters are told "to just use your phone"

        Newspapers used to send trained photographers out with reporters, but these days they don't employ either. Now it's considered enough for a "journalist" to remain in the office (or better still at home) to write up their report from minimal information often gleaned from social media or other news outlets and to use a photograph similarly sourced from social media or even a Google streetview image often of the wrong location.

      5. simonlb Silver badge

        Re: Pedant? moi?

        Steady now, most BL cars weren't even approaching mediocre, let alone 'good enough'.

        1. ravenviz Silver badge

          Re: Pedant? moi?

          Not even the Austin Ambassador Y Reg?

      6. steviebuk Silver badge

        Re: Pedant? moi?

        And if you submit your photos for the local rag to use they won't pay you for them, like they didn't mine, so I told them to remove them. Oddly they ended up removing every photo on the article, even ones that weren't mine.

        1. imanidiot Silver badge

          Re: Pedant? moi?

          The other ones were probably similarly used either without permission or without payment (and permission was thus removed).

  2. herman

    That seems like a fun place to work.

  3. Henry Hallan

    I don't know if our resident vulture watched the YouTube video all the way through - but it finishes with the rocket exploding

    1. FrogsAndChips Silver badge

      That's not an explosion, that's a fart after it has finished digesting itself.

    2. Inventor of the Marmite Laser Silver badge

      It didn't 'explode'. No sir. It had a Rapid Unscheduled Disassembly, as you should well know.

      1. midgepad


    3. NeilPost Silver badge

      One for SpaceX then.

    4. Spherical Cow Silver badge

      Was that a flame-based type of rocket pogo?

      1. david 136

        The article seemed to suggest the pulses were intentional, but didn't really explain.

        That leaves plenty of questions -- like whether the RUDifying pulse at the end was intentional as part of finding limits experimentally.

  4. imanidiot Silver badge

    "Instead, the plan is to use the technology to miniaturize launch vehicles further"

    That way madness lies if it's not just for hobby or research. There's not that much market for launching dedicated tiny sats to a custom orbit (counter to mass launching on a ride-share to a maybe not ideal but good enough orbit) and you're butting your head against strongly diminishing returns in propellant to payload mass fractions. A super big rocket (like SpaceX Falcon 9 or ULA Vulcan, is always going to be cheaper per KG to orbit than a tiny one.

    1. Anonymous Coward
      Anonymous Coward

      Pi’s in space ….

      1. James Hughes 1

        Quite a few already up there....

  5. Sparkus

    caseless ammunition

    meet structure-free rocket engines.......

  6. Doctor Syntax Silver badge

    Let's hope they teach it to know when to stop.

    1. IanRS

      Judging by the activity at 1:37, they didn't.

  7. Phones Sheridan Silver badge

    They made a rocket out of a hot glue gun???

  8. Mark 85

    Interesting but....????

    Given the complexity of control mechanism and changing of CG and thus higher costs and chance of failure what's the benefit? Don't the current solid fuel boosters/rockets work well enough? What am I missing?

    1. RegReader76

      Re: Interesting but....????

      I understood that parachutes would be attached to stages and used rocket engines to be recovered later for reuse. Is that no longer viable.

      1. Peter Gathercole Silver badge

        Re: Interesting but....????

        There are two problems with that model. One is that you're still hefting the structural elements up to a high altitude, which actually takes fuel. The other is where you let the boosters fall. If you decide to use the sea, as it's large and relatively empty, you have to cope with salt water damage, which required some re-manufacturing.

        This is why SpaceX soft lands their stages and boosters on land or at least on a barge. Less salt damage, but you thin have to cope with the extra mass of the fuel and still working engine and control systems to do the soft landing bit.

        What amuses me about this is that it's not really consuming it's structure. It basically looks like a solid fuel feeder system, a lot like (as someone pointed out above) a hot-melt glue gun. There is still a structure there pushing the solid fuel towards the engine, which remains after the fuel is used (at least until it explodes!) So what is being consumed beside the fuel?

        1. Jon 37

          Re: Interesting but....????

          The fuel tanks are big structural parts of the rocket. Removing them saves mass.

          Most modern rockets have 2 or 3 "stages". The reason they do that, is that the weight of the empty tanks is so high. At some point, it becomes better to get rid of the empty tanks, even if that means you have to carry an extra rocket engine up to power the second stage.

          If you could get rid of the fuel tanks the way this rocket does, that potentially makes single stage to orbit rockets possible. That reduces costs because you only need one set of engines, not two or three. It also gets rid of the complexity of the staging manoeuvre(s).

          Although there are other reasons you might want to stage anyway. In particular, the optimum nozzle design is different depending on the air pressure, so existing designs optimise the first stage engines for use in the atmosphere, and optimise the second stage engines for use in vacuum. But perhaps they can use a design that is good enough in both atmosphere and vacuum.

          Note that this is only really better than Falcon 9 if they can make the whole rocket returnable and reusable. Otherwise, Falcon 9 is throwing away a second stage, and this would be throwing away the only stage, so it's not going to be competitive.

    2. NeilPost Silver badge

      Re: Interesting but....????

      Commonly payload is atop of the rocket… so it feels inherently a bit iffy, without some structure around the self-eating rocket. Akin to the tool you use for sealant/caulk/no more nail cartridges.

      It seems like a great idea until you consider the top loading is at the opposite end to the pushing bit.

      Maybe for strap-on boosters only.

  9. Kevin McMurtrie Silver badge

    It looks like a hot glue gun with a stuck thermostat.

  10. Anonymous Coward
    Anonymous Coward

    No Scottish jokes?

    Nothing about how those Scots will eat anything, or how they probably solved the problem by deep frying the engine?


    1. Inventor of the Marmite Laser Silver badge

      Re: No Scottish jokes?

      You unutterable bar steward. That's reminded me of deep fried haggis (it really was actually very lovely) and now I'm hungry.

    2. Tim99 Silver badge

      Re: No Scottish jokes?

      I have seen someone mix a small bit of melted Mars Bar with an oxidizing agent. Yes, it deflagrated such that it could be used as rocket fuel. Deep frying it first would probably improve this.

      1. ravenviz Silver badge

        Re: No Scottish jokes?

        Deep fried battered Mars bars are actually very good! But not good ‘for you’!

      2. imanidiot Silver badge

        Re: No Scottish jokes?

        A mars bar is basically just sugar. Thus no wonder it burns well.

  11. Anonymous Coward
    Anonymous Coward

    prior art

    ISTR that the mythbusters tried something similar with salami.

    1. Benegesserict Cumbersomberbatch Silver badge

      Re: prior art

      They did gummy bears and dog poo. The latter left much more of a cloud of smoke.

      I thought the salami was Spike Milligan.

    2. Adrian 4

      Re: prior art

      Bacon lance

  12. mirachu

    Rocket rich exhaust?

  13. John Brown (no body) Silver badge

    An interesting idea...

    ...I'll be even more interested in how they will force-feed the rocket body to the engine in an actual flight vehicle that doesn't have the "glue gun" device pushing it down. Some sort of mechanical screw drive? A hydraulic collapsible exo-skeleton? I suspect whatever the result, it's going to be some interesting engineering and I assume they have some practical ideas on how to do this already.

    1. Ali Dodd

      Re: An interesting idea...

      don't think it's like a glue gun, it's just riding along the tracks and attached to the top of the engine so as that eats itself it pulls it along towards the engine.

      I think it's great, much more likely to be used in military rocketry I suspect to extend range of those with the low thrust size they are planning.

      1. Peter Gathercole Silver badge

        Re: An interesting idea...

        There is definitely a motor or something pushing the fuel, as can be seen when there is the blowback into the fuel rod that breaks it, and it still moves towards the engine after it is shattered.

    2. khjohansen

      Re: An interesting idea...

      This is a weight savings exercise, the elegant solution to "force-feeding" would be to have it collapse under its own mass @ 3-7+Gs acceleration

      1. Ball boy Silver badge

        Re: An interesting idea...

        Simple, innit: you have another rocket pointing the other way that pushes on the far end...

        Oh, hold on...


    3. grndkntrl

      Re: An interesting idea...

      I think a pulley/ratchet strap mechanism on the outside would probably work, with all of the motors & cable/strap take up spools located at the nozzle end so that it pulls the nose end towards the nozzle, instead of something (linear actuator) pushing the nose end as in the video.

      You could then have a parachute package in the nose cone to be able to recover the collapsed stack of nose cone & engine puck.

      If it needs to survive re-entry temps, then an inflatable heatshield a la LOFTID ( would also pack down quite neatly into the nose cone.

    4. druck Silver badge

      Re: An interesting idea...

      The thrust from the rocket engine would be pushing against the mass of the payload, although I don't know if this would be sufficient to feed the structure.

  14. bpfh

    Looks at LOHAN beer mug in cupboard

    Will she ever get a shot at space?

    1. imanidiot Silver badge

      Re: Looks at LOHAN beer mug in cupboard

      Without Lester Haines (RIP) that project is unfortunately dead as a doornail. I haven't even seen any SPB articles in a long while.

      1. bpfh

        Re: Looks at LOHAN beer mug in cupboard

        I know. Does anyone know what happened to LOHAN after the Spaceport America debacle?

        1. imanidiot Silver badge

          Re: Looks at LOHAN beer mug in cupboard

          I don't think it's been publicly stated anywhere. IIRC the flight article hadn't been shipped yet, so if it still exists I would assume it's somewhere with the Haines family.

          And I don't think the big problem was with Spaceport America, it was the FAA dragging it's heels on the required permits for the rocket motor and the flight (and then SA not doing anything to assist either)

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