Giant catapult defies gravity by launching satellites into orbit without the need of rocket fuel
www.thebrighterside.news
Satellites are critical for monitoring Earth's health, identifying issues like methane leaks, and conducting various other types of research.
  • superkret@feddit.org
    17·
    2 months ago

    This is just investor bait.

    Remarkably, this process eliminates the need for rocket fuel

    No, it doesn’t. It’s physically impossible to fling something into orbit from earth.
    You can fling it into space, but you need a circularization burn or it will just fall back down.
    And since you can’t accelerate anything past Mach 5 or so inside the atmosphere, the circularization burn will need to be 90% of the delta V.

    • arandomthought@sh.itjust.works
      3·
      2 months ago

      Thanks for the detail! I thought it should definitely be possible in theory to throw something into orbit. But you’re right, I didn’t think of the atmosphere and its friction. You would also have to throw at a very flat angle so theres a lot of atmosphere for your projectile to pass through.

      • superkret@feddit.org
        9·
        2 months ago

        Even without air friction, and no matter how flat you throw it, you’d always throw it into an elliptical “orbit”. But the lowest point of the ellipse would still be on the surface, no matter how high the upper end is.
        So it would always come back down, unless you give it another push at the highest point (in space).

        If you just throw it even faster, you’ll hit escape velocity and it would leave earth entirely.

        • arandomthought@sh.itjust.works
          2·
          2 months ago

          Makes sense as well. So the projectiles they throw not only have to be able to withstand the launch and release the payload, but they also have to be functioning rockets to allow for a circulation burn…

          Well good luck to them.

          Edit: I think I had that animation in mind where the canon shoots a canon-ball into a circular orbit (don’t remember where I saw it), but I guess that’s impossible, too, then. >.<

          • Ageroth@reddthat.com
            1·
            2 months ago

            Just build a tower taller than the atmosphere, now you don’t need rockets because you have a space elevator.

  • Pennomi@lemmy.worldEnglish
    10·
    2 months ago

    That’s a very optimistic headline. They haven’t made any orbital launch attempts, as far as I can tell.

    The whole article looks like it was written by an amateur space journalist that has no idea what is going on in the industry, but falls for all the marketing.

    • Mike1576218@lemmy.ml
      3·
      2 months ago

      Also: getting up is easy. The hard part is getting fast enough so you don’t fall down again. So you still need quite some fuel no matter how high you can throw.

      BTW: Spinlaunch knows this of course. They plan to sling a rocket into space to get the payload to orbital speed. Funny that is not mentioned in the article.

    • arandomthought@sh.itjust.works
      2·
      2 months ago

      Yeah, when I first heard what they are trying I was extremely sceptical. Watching some YouTube videos that talk through the physics involved didn’t help much. So I was extremely, surprised reading this headline and thinking they actually got something into orbit. I’m somehow both relieved and upset that they didn’t.

  • Elchi@feddit.org
    01·
    2 months ago

    Just imagine how much more efficient this could be with a clearly superior launching device like the trebuchet.