554
Original Apollo 11 code open-sourced by NASA — original Command Module and Lunar Module code repos are now public domain resources (www.tomshardware.com)
submitted 6 months ago by to c/opensource@lemmy.ml
49 comments fedilink hide all child comments
you are viewing a single comment's thread
view the rest of the comments
[–] 6 points 6 months ago (6 children)

If that works with the real solar system mod that is honestly the finest testament KSP can get for its mathematical accuracy.

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 6 child comments
    •
  • [–] 4 points 6 months ago (2 children)

    KSP is not mathematically accurate and it can't be or it would have trouble running on computers. They split up and use simplified 2 body dynamics in the game.

    We use super computers to model the n-body problem bcz of how complex it is.

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 2 child comments
    •
  • [–] 1 point 6 months ago (1 child)

    Of course, NASA ain’t modelling actual missions in KSP.

    I imagine KSP is simple Newtonian physics which is accurate at macro-scales, whereas obviously NASA is going to use Einstein’s equivalent. Far more computationally intense but really important once you scale up the small errors in Newton’s equations.

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 1 child comment
    •
  • [–] 3 points 6 months ago*

    Actually, we don't use relativity so much. For some stuff like light time delays, yes, but for orbit determination we use newtonian mechanics still. It's just that once you start adding more than two bodies, you have to shift to doing numerical integration to find solutions, which doesn't work for real-time stuff like video games.

    For most applications, F = -GM1M2/r^2 is still a valid approximation.

    Edit: And by most applications, i mean sending a satellite to a planet in our solar system. If you were trying to go to Alpha Centauri, you damn sure better use Relativity to model your trajectory.

  • permalink
  • fedilink
  • source
  • parent
  • [–] 3 points 6 months ago (2 children)

    I haven't tried it, but yeah, at small scales KSP (which is just using floating point numbers) is pretty accurate. It's at large scales where it fucks up, which it does have to deal with too, being a game about traveling between planets.

    I assume it probably would work though. The Apollo computers, as I'm sure you know, weren't super complex. They basically just assisted the pilot. I'm not exactly sure what math they did, but it probably just had to do with descent rate/time to impact and stuff like that. Again, this is all just guessing. I don't remember it.

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 2 child comments
    •
  • [–] 2 points 6 months ago (1 child)

    That makes sense, floating-point precision falls apart with large numbers but is pretty good with small numbers.

    Perhaps there’s a mod that can swap out the position system to use doubles instead of floats? But I’m pretty sure that’s a Unity thing with its Transform positioning system so that’d be quite a challenge to change.

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 1 child comment
    •
  • [–] 3 points 6 months ago* (last edited 6 months ago)

    Yeah, there's no way to do that. You can use doubles yourself to track things, but the engine is always going to use floats. When you send data to the engine, it has to be in float form.

    IIRC, UE5 actually switched to using doubles for everything. Standard size float makes floating point math faster to perform, but computers are fast enough now they decided it was worth it. It can now accurately store positions much further away without losing as much precision.

    KSA is also using doubles I think, on their custom engine. They can do a cool thing where they can render multiple vehicle views at once, in totally different locations. KSP couldn't do this because of floating point error.

  • permalink
  • fedilink
  • source
  • parent