LaGrangian Points of Kerbin and other bits of orbital mechanics?

[Andr0s]

Hello Kerbals!

Short-time player, first-time writer, biggest fan and all that. And I had a fairly open question:

I'm not much of a rocket scientist, but just a bit of a space flight book geek so of course some of the "iconic" objectives of space flight hold quite a bit of appeal for me. So, I wanted to start tossing some debris up into the L-points around Kerbin - only no amount of Wiki- and Forums-scrubbing revealed anything on the subject. So I was wondering: Does the game physics model entertain Lagrangian orbital mechanics? Has anyone done any work figuring out the L-points for any of the planets in Kerbol's system? I'd love to try (most likely unsuccessfully) to park some stuff at Trojan points, give Lissajous orbit a shot and the like.

Thanks!

Edited August 27, 2013 by Andr0s
Answered.

[Johnno]

KSP uses singlebody physics so there are no L-points etc. Meaning you can only ever be in a single sphere of influence.

Geostationary orbits are about the only fancy-ish thing you can do.

[Mr Shifty]

Lagrange points actually get suggested so often that they're on the Do Not Suggest list:

http://forum.kerbalspaceprogram.com/showthread.php/36863-What-not-to-suggest

If you're set on visiting L-points, you could check out Orbiter:

http://orbit.medphys.ucl.ac.uk/

EDIT: Welcome to the forums!

[Andr0s]

Thank you gentlemen!

Mr. Shifty, you dream-smasher (Sorry I didn't see the do-not-suggest list, still stumbling through forums. I think I'll still keep my fingers crossed for inclusion of L-point physics at some date, they make things so much more fun.)

~Andro

[VoidPointer]

That said, it's (almost certainly) possible to set up an orbit that's so close to a Lagrangian one that it would probably take years for the difference to become significant. Especially at a point that isn't L2, since they require crazy levels of stationkeeping anyway.

It's the power of IMAGINATION.

[Andr0s]

@VoidPointer: But... but... no L-points means no Lissajous orbits, which are trippy-fun! (Although I think trying to set up a Lissajous in a 2-moon config would hurt my brains something awful.) Also, I want my Horseshoe orbits too! *sulk*

[Raptor831]

Since orbits are (essentially) infinitely stable, there's really no gameplay reason to even model L-points. But, I'd still like to see them just for the cool factor. But I can live without. It hasn't affected my gameplay yet anyway!

[Mr Shifty]

That said, it's (almost certainly) possible to set up an orbit that's so close to a Lagrangian one that it would probably take years for the difference to become significant.

How? The Kerbin-Mun L1/L2 would be about 2.2 Mm away from the Mun, which is actually just inside the Mun's sphere of influence, meaning that objects there would orbit the Mun with a period of about 22.2 hours. Since an object orbiting at a real L1 or L2 would remain stationary with respect to the Kerbin-Mun axis, it would only take minutes or seconds for the difference to become apparent.

I suppose you could kill your rotational velocity out there, point your engines at the Mun and try to do a continuous low burn to keep your altitude constant. If you have a 10 ton vessel, it would only take about 134 N of continuous thrust to stationkeep, which an LV-1 could easily manage. If it had a full FL-T200, it would take about 4.5 hours to run out of fuel.

[VoidPointer]

Okay, I must have my L numbers wrong. I was thinking of the one that's on the other side of the planet from the Mun. Oops.

It would probably work in the Kerbolar system, though. Maybe. Depends on the SoI to orbital path ratio... thing.

[Technical Ben]

I know discussions of this are frowned upon... ... but, this video got me thinking: http://youtu.be/mxpVbU5FH0s

Moons and asteroids get "trapped" at L4 and L5 anyhow. So would it not be ok to add a moon/asteroid to land on at these points for Kerbol and Jool? At least then a stationary base can be added and no game physics is broken (planets are on rails, not simulated).