Slashdot Mirror

← Back to Stories (view on slashdot.org)

Gigantic Air Gun To Blast Cargo Into Orbit

Posted by timothy on from the phwipt-phwipt dept.

Hugh Pickens writes: "The New Scientist reports that with a hat tip to Jules Verne's From the Earth to the Moon , physicist John Hunter has outlined the design of a gigantic gun that could slash the cost of putting cargo into orbit. At the Space Investment Summit in Boston last week, Hunter described the design for a 1.1-kilometer-long gun that he says could launch 450-kilogram payloads at 6 kilometers per second. A small rocket engine would then boost the projectile into low-Earth orbit. The gun would cost $500 million to build, says Hunter, but individual launch costs would be lower than current methods. 'We think it's at least a factor of 10 cheaper than anything else,' Hunter says. The gun is based on the SHARP (Super High Altitude Research Project) light gas gun Hunter helped to build in the 1990s while at the Lawrence Livermore National Laboratory (LLNL) in California. With a barrel 47 meters long, it used compressed hydrogen gas to fire projectiles weighing a few kilograms at speeds of up to 3 kilometers per second."

8 of 384 comments (clear)

  1. G-forces ???? by Anonymous Coward · · Score: 5, Interesting

    Just wondering how they plan to address the problem of controlling the G-forces and prevent damages to the cargo.

    The cannon idea was tried before ...... not a test single cargo survived the trip (or made it to orbit).

    1. Re:G-forces ???? by riboch · · Score: 4, Interesting

      They probably hope to discover "inertia canceling."

      I could not find it in the article, so:
      What are the power requirements for such a mechanism?
      Where will it be located?
      What about ITAR issues?
      Why not make it longer for smaller accelerations?

      The concerns about the hypersonic regime of fluid flow should not be an issue if they fire from a mountain, there are a hand full of craft that can handle the plasma, although none accelerate like that at such a low altitude.

      Aside, what happens to fuel (liquid and solid) under such high g-load? I can find no studies on it.

      P.S. I am an Aerospace Engineer.

      --
      GO BLUE!
    2. Re:G-forces ???? by Nyeerrmm · · Score: 4, Interesting

      Actually, the ability to cheaply fill fuel depots in orbit does a significant amount to reduce the problems associated with current launch technology. Consider Apollo. The massive Saturn V rocket was required because in addition to taking the CM, SM, and LM to orbit, it also had to take the fuel to get it from LEO to the moon -- fuel was the most significant fraction of the mass (2:1 or 3:1 if I remember correctly). Instead, if this had been available to move fuel to orbit on the cheap, you could have used a couple of Saturn IB rockets and rendezvoused in LEO with a freshly filled Earth departure stage. I wouldn't be surprised if it would have been able to cut the cost of Apollo in half. This could also allow a new moon mission architecture without the massive Ares V.

      Remember, space missions are like exponential Russian nesting dolls. If you remove a layer (in my example, the EDS), you can reduce the initial launch mass drastically. This is why things like ISRU and various electric propulsion schemes are such hot topics, even though they don't help you get off the ground either.

    3. Re:G-forces ???? by sjames · · Score: 4, Interesting

      Actually, it solves a LOT of current issues. Maneuvering fuel, food, water, and medicines for example are quite durable under G-force. Those are a large part of what the ISS resupply missions are carrying. The Progress mission hardware isn't reusable either but is likely considerably more expensive than a solid booster with a dumb cargo capsule.

  2. Gerald Bull by Scrameustache · · Score: 4, Interesting

    Gerald Bull was Canadian engineer who died (bullet in the head) trying to build such a cannon.

    See http://en.wikipedia.org/wiki/Project_HARP

    --

    You can't take the sky from me...

    1. Re:Gerald Bull by Anand7 · · Score: 5, Interesting

      Bull was killed by Mossad because he was helping Iraq build a "supergun". You make it sound like he was killed because of Project HARP.

      Gerald Bull designed his "super gun" to put payloads into orbit. He approached the US government with the idea and they rejected it as a launch method but wanted a weapon. Disgusted and disillusioned (he was apparently treated very poorly) his response was to create a truly powerful weapon. Iraq hired him to build one for them. The Mossad killed him in Belgium, a country that exports arms all over the world. It's important to remember that the US military has done this with a number of inventions. The guy who invented the x-ray laser had wanted to use it for medical purposes; excising tumours etc. The US military classified it and now it's a weapon. Another Canadian invented polymorphic encryption for secure banking and corporate communications...US military classified his work and as far as I know he can't even talk about it with his peers.

  3. G force. by jklovanc · · Score: 4, Interesting

    I may be wrong in this calculation but running the numbers I get a weird result.
    The gun is 1.1K long with a final velocity of 3km/s.
    So the payload would be in the gun for 1.1/(3/2) = 0.73 seconds.
    In that 0.73 seconds the payload would accelerate to 3 kms/sec The continuous acceleration would be 3000/9.8/0.73= 417 Gs. That is sure a lot of Gs. Much more than the 3.2 the shuttle produces.

  4. Re:nothing new here by Deadstick · · Score: 4, Interesting
    gun-fired projectiles with electronic fuses are a decades-old technology

    Matterafact, the proximity-fuzed antiaircraft shells of WW2 had a vacuum tube in them.

    rj