Make "time to launch" work for targets that are celestial bodies

[jd284]

The function that displays when we can launch into a target orbit works only for vessels.

It would be nice if it would also work for e.g. Minmus, however when Minmus is targeted, the "time to launch" option currently does not appear.

There should be no need to change the function that calculates the timer, only maybe the orbit details have to be retrieved in a different way.

[TriggerAu]

I didnt put that in as the math is premised on the idea that the vessel is orbiting the same parent as the target, so this would only be used in most cases for Launch straight to Mun/Minmus - was a really small use case so wasnt going to spend much time on that. Is that cool?

[jd284]

The math doesn't change though, and you should be able to keep most of the code. I can't currently compile KAC in a way that KSP can load it to check, but it should work if you just remove the "is vessel" check. After all the bodies are still ITargetable and have GetOrbit() just the same so I don't see why there's a need to make an exception for them.

While I agree that for stock KSP it's not much of a use case, but even then it would be quite useful. On the other hand for RSS with its highly inclined Moon orbit it would be extremely useful.

Also just from a usability point, it happened several times to me where I was looking through all KAC tabs to find where the heck that time-to-launch function was, until I realized I hadn't targeted a vessel and so it wouldn't show up at all.