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The Science Behind Building a Space Gun

Posted by samzenpus on from the acme-approved dept.

An anonymous reader writes "Astronomer and gamer Scott Manley (more famous for his Kerbal Space program coverage) has created a fantastic video explaining the science behind building guns that could one day be used to launch payloads into space. It's not as easy as simply making a bigger gun, there's a whole host of unorthodox 'gun' designs which work around the limitations of garden variety propellants."

5 of 131 comments (clear)

  1. Re:I estimate it will be about a week by Anonymous Coward · · Score: 5, Interesting
    LOL no kidding. Paging Dr Gerald Bull!

    http://en.wikipedia.org/wiki/Gerald_Bull

  2. Obligatory by Kylon99 · · Score: 5, Interesting

    In honor of the time before xkcd, but in the style of such:

    http://en.wikipedia.org/wiki/From_the_Earth_to_the_Moon

  3. Scaled Down Particle Accelerator by dns_server · · Score: 4, Interesting

    Why not scale down the LHC and build something that is capable of accelerating something relatively small say 10-100kg fast enough to make it to orbit instead of accelerating atoms to nearly the speed of light.

    The problem with conventional rockets is you need to carry the fuel to get in to orbit as well as the fuel to go where you need to. The bigger the ship the more fuel you need to carry to overcome the weight of the fuel.

    If you can split the carrying of fuel for your journey from getting your rocket in to orbit you would not need to waste as much fuel lifting itself.

    You could set up an automated system that would fire a 10kg payload of fuel every 10 minutes and get what you need over time far cheaper than one big launch.

  4. Re:This is all well and good, but... by F34nor · · Score: 4, Insightful

    Everything is expensive. As to what to do with a gun, just launch water into space. It provides fuel, air, food, and of course water.

  5. Re:Inexpensive way to send up inert objects by DerekLyons · · Score: 4, Interesting

    One problem, as I understand it: a projectile launched from a big space gun would need to have its orbit adjusted or it will return to Earth. The video mentioned this issue briefly

    All gun schemes mention this 'briefly', if they mention it at all (most don't) - mostly in hopes that nobody will notice. The mass of the engines and fuel needed to circularize the orbit dominates the payload, and is *very* difficult to make resistant to the shock and acceleration. It's pretty much a showstopper all by itself, without even mentioning the need for (the currently non-existent) heat shielding needed to protect the payload on ascent. As the vehicle bleeds off energy to atmospheric drag and gravitational forces as it coasts upward, it has to leave the muzzle of the gun at considerably more than orbital velocity... essentialy exposing the payload to re-entry conditions at launch.
     

    P.S. I saw proposals for an Apollo-style mission from Earth to Mars: a single giant rocket launches everything in one launch. Why is anyone even looking at doing it that way?

    Nobody that I'm aware that's even remotely serious is proposing to do it that way.