How do I know whether my orbit is perfectly equatorial?

[THX1138]

How do I know whether my orbit is perfectly equatorial? I'd like my refuelling station to be as close as reasonably possible <0.1 degrees.

[mk1980]

i think the mun is at an exactly equatorial orbit. you should see from the ascending/descending nodes how far off you are.

[THX1138]

28 minutes ago, mk1980 said:

i think the mun is at an exactly equatorial orbit. you should see from the ascending/descending nodes how far off you are.

How convenient! Thanks

[A_name]

Alternatively, use KER or Mechjeb, they show your orbital inclination among other useful stats.

[Geschosskopf]

5 hours ago, THX1138 said:

How do I know whether my orbit is perfectly equatorial? I'd like my refuelling station to be as close as reasonably possible <0.1 degrees.

You'll never get it EXACTLY equatorial, probably not within +/-0.1^.   This is due to inherent errors in KSP, which accumulate over time.  But you can get close enough for government work and really won't notice the slight inclination.  So just launch as close to 90^ as you can, then eyeball it off Mun as @mk1980 suggests.

[bewing]

Naw, you can get it a lot closer than just .1 degrees. The best you can do is NaN degrees. As said above, target the Mun. This gives you nodes that are marked in .1 degree increments. Just before your next node, lock SAS on Normal/Antinormal and do the standard burn -- this will push the node ahead of you as the angle decreases. As you get closer to 0.0, the node will move faster when you burn. But the closer you let the node get to you before you burn, the slower it moves at first.

You have to use the thrust limiter, but you can set it all the way down to .5% of full, and then you can easily control it to 5% of that with Shift. But with severe thrust limiting and carefully timed small taps of thrust, you can pretty much always get the node down to NaN degrees. And once you get it below .1 degrees, you can still see by the movement of the node when you burn that you can make progress getting to a fraction of that.

But if you are coming up on a descending node, and you do a tiny burn, and the node whips around in front of you faster than you can follow and you end up with an ascending node right behind you -- then you just went all the way through NaN degrees and past it.

Edited June 4, 2016 by bewing

[cantab]

In the stock game the only generic way is to inspect the savefile. Orbiting Kerbin or Jool you can use the Mun, Laythe, or Vall as a reference because they are in perfect equatorial orbits. (Note that Ike and Tylo are not, they have slight inclinations).

With mods, KER will read out your inclination directly.