back to article You've heard that pop will eat itself. Boffins have unveiled a rocket that does the same

Scottish boffins, along with colleagues in Ukraine, have developed a "self-eating" rocket engine that could affordably fling a cubesat into orbit. The solid-fuel rocket does away with heavy tanks, with the propellant itself forming much of the launcher's structure. As the engine burns its way through that structure, the rocket …

  1. Dave Pickles

    Like a hot melt glue gun stood on end

    ... with the payload on the top of the glue stick? Doesn't that mean that the rocket gets shorter as it burns, that must give some interesting aerodynamic problems.

    1. Anonymous Coward
      Anonymous Coward

      Re: Like a hot melt glue gun stood on end

      "Like a hot melt glue gun stood on end"

      Well, once you've added the control circuitry and actuators, it will be a bit more like a 3d printer that's been set on fire.

    2. Wellyboot Silver badge

      Re: Like a hot melt glue gun stood on end

      >> interesting aerodynamic problems. <<

      Possibly not too many, the aerodynamic impact will lessen rapidly with altitude and thrust gimballing will become more important. CoG will stay somewhere in the middle between the converging motor & payload.

      Having the fuel sufficiently stiff to survive launch stresses does sounds like a new rocket problem though.

      For small rockets no payload separation system may be needed, the spent motor can just ride along until the whole thing drops out of orbit.

  2. Herring`

    I saw PWEI when they were a grebo guitar band and then a couple of years later when they were doing samples and stuff.

    I realise this comment does nothing to advance the debate.

    1. Inspector71

      Any mention of Stourbridge's finest is OK with me. 28 years since Touched By The Hand of Cicciolina....bloody hell. Still the best World Cup theme ever.

      Sigh.

      1. Anonymous Coward
        Anonymous Coward

        >Any mention of Stourbridge's finest is OK with me. 28 years since Touched By The Hand of Cicciolina....bloody hell. Still the best World Cup theme ever.

        But were Stourbridge's finest, PWEI, Ned's or The Wonderstuff...

        1. Inspector71

          On record and of course T-shirts, the Poppies have it for me.

          Live, Ned's just edges it.

          If you disagree then there is no love between us anymore.

          1. Sam Therapy

            The Wonder Stuff. No debate.

            1. Sloppy Crapmonster

              No no no no no no no no no no no no, no.

        2. Anonymous Coward
          Anonymous Coward

          For me, Ned's were the bigger bunch of piss heads, although never got drunk with the Stuffies.

          Although as surreal sweaty gigs go, Sheep On Drugs at Birmingham Uni has top them all ,especially when the fire alarms went off.

      2. james_smith Bronze badge

        When the Poppies performed their footy theme song on Top of the Pops they had Patricia Morrison of Gun Club and Sisters of Mercy fame standing in for Cicciolina.

        And although this doesn't advance the debate, by convoluted coincidence I happen to be wearing a Gun Club T-shirt today.

        1. Sloppy Crapmonster

          Not now, James.

    2. Noonoot

      can you dig it indeed

      Herring` - Great years. PWEI - gig at Birmingham's NEC, touring with the Wonder Stuff.

      https://www.youtube.com/watch?v=36nWNAvtwrw

    3. hplasm Silver badge
      Happy

      Duncan Jones's Moon

      Also related to a certain Mr Bowie...

      this comment also does nothing to advance the debate.

  3. Anonymous Coward
    Anonymous Coward

    Not new

    Many self-lunching rockets have been built in the past. The problem of directing the thrust thus produced, and avoiding also combusting the payload, has however proven hard to solve.

    1. steelpillow Silver badge

      Re: Not new

      " The problem of directing the thrust thus produced, and avoiding also combusting the payload, has however proven hard to solve."

      This rocket has a relatively conventional combustion chamber with convergent (and, in practice -divergent) nozzle to direct the thrust in the usual way. Steering also needs adding, as it does for any rocket, and is a mature technology. A non-combustible stub between the payload and the fuel rod should protect the former from combustion.

      But sending a plastic spear through an oxygen-rich atmosphere at high Mach number may prove less practicable.

      1. Ken Hagan Gold badge

        Re: Not new

        "But sending a plastic spear through an oxygen-rich atmosphere at high Mach number may prove less practicable."

        It's not a bug, it's a feature, though probably only for version 2.

        You add some inlets to your device, figure out the amount of oxygen available to you at different points in the flight, and so reduce the amount of oxidant needed in your stick at those points (as measured up the stick).

  4. Roger Greenwood
    Pint

    I love the $5 multimeters in the picture

    I've got a couple of those as well. Bought to be essentially disposable, they have proved remarkably rugged and even more surprisingly, accurate. Top boffinry.

    1. Anonymous Coward
      Anonymous Coward

      Re: I love the $5 multimeters in the picture

      <iI love the $5 multimeters in the picture</I>

      Ha Ha - that's the first thing that struck me about the picture too, but I didn't like to say until someone else mentioned it!

      I hope they've patented the tech so that they can capitalize on it in a few years - micro satellites and micro rockets are the future! (Well, some of it).

      1. Anonymous Coward
        Anonymous Coward

        Re: I love the $5 multimeters in the picture

        I hope they've patented the tech so that they can capitalize on it in a few years - micro satellites and micro rockets are the future!

        You don't think that MoD will be thinking how they can muscle in, seize and monopolise the technology, exclude all beneficial and commercial applications, and turn it into a multi-billion quid failed weapon system? Just like they did with Reaction Engines.

    2. Mike Richards

      Re: I love the $5 multimeters in the picture

      It does look rather like the great British shed has been involved in producing this bit of boffinry. I trust a suitably Bryllantined pipe-smoking gentleman is lurking just out of view.

    3. JeffyPoooh Silver badge
      Pint

      Re: I love the $5 multimeters in the picture

      "**Scottish** boffins..."

      Coincidence? I don't think so.

  5. Andrew Oakley

    High tech gurus

    Ah, the Kidderminster Market Tavern. Somewhere between the Blues Brothers Country & Western skit and Delverance, and that was assuming there was a friendly crowd.

    1. Anonymous Coward
      Anonymous Coward

      Re: High tech gurus

      Wow the Market Tavern.

      Part of the fun was not only surviving the gig, but then surviving the Kiddy subways afterwards.

      1. Noonoot

        Re: High tech gurus

        Try surviving a New Model Army gig.

  6. Zebo-the-Fat

    Is that a spark plug at the bottom of the engine?

  7. imanidiot Silver badge

    No casing? I don't see how you could provide the needed shove to get the rod into the engine without some form of supporting structure. And you need a place to put the electronics and payload. It might not be the traditional sort of motor casing associated with a solid fuel motor that has to withstand the full operating pressure over it's entire length, but I'd still call it a motor casing.

    1. John Smith 19 Gold badge
      Go

      No casing?

      Well there are a few options to avoid the weight of a casing.

      One is to pull the top part toward the bottom with a pair (or three) of winches.

      Another is to have no "top" and mount everything around the chamber, with rod being fed in by a pair of pinch rollers.

      It's one of those "That's so obvious, why did no one else do it before" ideas.

      But I don't think anyone has. Keeping the oxidizer from the fuel would in principal make for safer propellant.

      On a flight dynamics basis I think that (unlike conventional solids) the shortening compensates for the mass loss so the CoG (roughly) stays in the same position, potentially making the control problem a bit simpler. Maybe.

      1. Denarius
        Thumb Up

        Re: No casing?

        outer casing made of self lubricating plastic. How about a simple coarse thread in plastic above reaction chamber where plakki still firm and rotate a feeder nut ? I do wonder how any non-metal or ceramic will handle the upper chamber combustion pressure no matter what method is used. Concept is worth playing with.

        1. The First Dave Silver badge

          Re: No casing?

          A feeder nut will only work if you can keep the thread from rotating.

    2. Ken Hagan Gold badge

      The bottom of the stick is being melted by the heat of the combustion chamber. Some downward force is applied by the upward acceleration of the rocket. This is "mg" just prior to launch, when the stick is heavy, is slightly larger when the engine starts or else it won't lift off, and remains at that slightly larger value throughout the flight as long as you are burning the stick at a uniform rate. Note also that the thrust is constant even as the stick gets lighter, so the actual acceleration is presumably pretty huge near the end of the burn. Probably not person-friendly. Stick to cube-sats.

      The cube-sat itself might reasonable be placed at the other end and be given a heat-resistant beanie to wear for the flight, thereby reducing the problem (mentioned further up) of firing an inflammable stick through oxygen at high Mach numbers. I imagine the sides of the stick would see less atmospheric friction and might be protected by a thin layer of something air-tight.

  8. YARR

    It's only rocket science

    Could one of these carry a cubesat all the way to geostationary orbit?

    ... and fit within the missile launcher of a submarine?

  9. Chris 239

    Thrusting

    Not enough mention of thrusting ones rod for for a Register article.

  10. anonymous boring coward Silver badge

    "The engine itself has yet to leave the lab at the Oles Honchar Dnipro National University in Ukraine and currently consists of a 20mm diameter fuel rod fitting into a 50mm combustion chamber."

    So only months away from achieving orbit then?

  11. Steve Jackson
    Pint

    Inject Me

    I'm on top of the world, can you see that far?

    Ha! Ha! Look at me Ma! I can fly as high as the sky, I am sci-fi!

    You care to say, "Hi!"...I say bye-bye My positronic ray will blast the day away

    So be warned!

    Grolsch, obviously.

  12. ShadowDragon8685

    You know, I can't help but wonder - if they make this small enough, this rocket could be meaningfully assisted with a mechanical launcher - cannon/accelerator of some sort from the ground, or even just taking the little sucker up high on a plane.

    1. Denarius

      Heinlein

      When will the Chinese run a high speed maglev rail launcher up the side of the Himalayas ? See end of "The Moon is a Harsh Mistress". Aside from that Shadow*, orbital or close missiles have been launched from under planes for years. Merkins sat killer was launched from an F15. Orbital Sciences also come to mind.

      Given the sort of market this "hobby" rocket is aimed at, the cost of aerial boost is high and one can be sure aviation/space management will be anxious to control anything likely to go near low earth orbit, let alone higher.

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