Bouncing apsis

[chrisl]

It doesn't always happen, and it might happen more with larger ships (haven't really tested) but why is it that sometimes you'll make a course correction and your apsis (apoapsis & periapsis) will be stable, while other times they seem to bounce all over the place? Usually the bounce doesn't seem to be more then a few meters, but it can sometimes make it difficult to plan out new course adjustments. Just wondering if anyone knew why it happened and if there was anything that could be done to stop it.

[Boomerang]

This tends to happen when with more and more severity as you approach an eccentricity of zero because of floating-point errors in calculating your orbit. So if you've done a really good job of circularizing your orbit and the bouncing around is becoming problematic, you can either give it a minute to try and sort itself out (it might not) or make a very slight burn/RCS correction to make your orbit a little less circular.

If this is happening to you on interplanetary trajectories, you'll get orbits that bounce in and out of your destination SoI because of the same sort of errors and generally the further out you are, the worse it is. It's also somewhat of a symptom of your trajectory just barely getting to your target. So if you can make your initial ejection burn a bit more accurate, to put you deeper into your target's SoI, your projected orbits will tend to be more stable.

[prophet_01]

Another source is whoble. bigger ships are much more affected and make it bounce brutally while and after turning. Time warp 5 and back to normal can help with that. But the floating point is the problematic one :/ when performing gravity assists/slingshots it gets bad... the smaller shifts make huge differences and plotting a course can be a problem

I also experienved it a lot when "docking" with asteroids outside kerbins soi's. The only thing I could tldo was to perform multiple small maneuvers on approach. course whoble is still my mortal enemy atm

[chrisl]

Well, at least I know it's not really something I'm doing wrong.