Adjusting the LAN in orbit.

[Trinexx]

Does anybody have a simple explanation of how you move the longitude of the ascending node once you're already in orbit? I've been removing inclination then just tilting it back up once I'm at a given point, but I pretty much have no idea what the heck I'm doing so it never ends up the way I want it to.

[KatzOhki]

Thrust normal / anti normal at a point between the AN and DN should do it. Why do you want to do this?

[Trinexx]

Got a kethane scan probe in polar orbit and I want it to straddle the terminator so it doesn't run out of power on the dark side.

[Mr Shifty]

If you're trying to match orbits with a target, you wouldn't care about the Kerbin-relative LAN, you just want to burn at the relative AN or DN to match inclinations. I can't really imagine another situation where the LAN matters, since celestial bodies will all rotate underneath you.

[Mr Shifty]

Got a kethane scan probe in polar orbit and I want it to straddle the terminator so it doesn't run out of power on the dark side.

There's no orbital precession in KSP, so you can't make it stay on the terminator throughout the year. If you're just trying to get it to be there long enough to scan for a few days, then you want to burn normal or anti-normal (toward the closest terminator) when you're over either of the poles. That should rotate the orbit around to where you want it. Note that if you're trying to rotate it by more than a few degrees, this could be a very long burn. (deltaV = 2 * sin (angle/2) * velocity) If it's more than about 50 degrees, you'll actually save fuel by raising your apoapsis (over a pole) out to near the edge of Kerbin's SOI, rotating it there, then lowering it again. Might be better to de-orbit the scanner and launch another one north or south-ward at dawn or dusk. Or just add more batteries.

Edited October 18, 2013 by Mr Shifty

[Trinexx]

Awesome, that worked wonders. Thanks!