Adjust Orbital Plane/Inclination without messing AP and PE

[angeldust]

Hello all,

I'm trying to Map Kerbin with the Mapping satellite mod and encountered somewhat of a problem:

I got my Satellite in a stable 80 km orbit and It is working fine... but it is just recording a stripe. Now I thought: right, it has to somehow move from south to north (or vise versa) (I have the orbit on around 90°). But how to do this?

I mean how can you permanently rotate your orbit without messing with your altitude?

And by the way: It won't map while warping. Is there a fix for that or is it simply not possible?

Thanks for your help

Angeldust

[AlexL]

Yes, if you burn your engines perpendicular to the direction you're going,while also pointing towards the horizon you can change your plane without altering pe/ap altitudes.

[Nibb31]

The ISAMap plugin can map up to 4x warp.

To change inclination with MechJeb, set the Attitude to NORMAL+ or - and burn (which is the same as what AlexL said).

[phoenix_ca]

Just keep in mind that inclination changes are very costly. If you have a choice, it's better to get to the right inclination in the first place, e.g. establish inclination as part of your ascent.

So yeah, burn NORM+ or NORM- , but make sure you do this at the orbital nodes. (Erm, read the article up to the math. No need to bog-yourself down with math in KSP. )

[bsalis]

I would launch again with a north or south heading.

The inclination change you want to do i'm thinking is about 4500 m/s !

Possibly don't even have the fuel for that.

[Fuzzy Dunlop]

An inclination that big will require almost as much fuel as getting into orbit in the first place. But you can make it much less costly by doing the burn futher away from kerbin (put yourself into a highly inclined orbit and change the inclination at apoapsis). It might even be worth slingshotting around the mun (I've used that to go from prograde to retrograde).

But the simplest solution is just to launch north or south...

[angeldust]

thank you ever so much for your help!

ok, I got the basic concepts of inclination change... but to map all kerbin I would have to do a perpetual inclination change, don't I?

so how to do that? other people got a whole map of kerbin but vy simply orbiting around it I just would get a small stripe. so what to do? a perpetual burn normal to my orbit?

[Fuzzy Dunlop]

If your in a polar orbit kerbin will rotate under you

[EndlessWaves]

If your in a polar orbit kerbin will rotate under you

That's true for almost any orbit. Kerbin rotates fairly slowly so unless your horizontal orbital speed matches the rate of rotation you'll move at a different rate to the planet and map everything between the highest and lowest latitudes your orbit passes over.

Surface rotation speed is 174.5m/s, although it will be more depending on orbital altitude.

[angeldust]

If your in a polar orbit kerbin will rotate under you

Ah... see that was kind of dumb of me....

@EndlessWaves: Yeah... but when your Orbit is at 90° the rotation does not change your position on Kerbin, but rather adds to your orbiting velocity. So North/South Orbit is best to map Kerbin, as You have Kerbin practically changing the plane of your orbit in respect of an absolut position on Kerbin.... easy, right?

[Vanamonde]

That's true for almost any orbit.

But not every orbit will take you over the poles, whereas a polar orbit will take you over everywhere else as well, eventually.

[EndlessWaves]

But not every orbit will take you over the poles, whereas a polar orbit will take you over everywhere else as well, eventually.

Indeed, a polar orbit is required to get top down coverage for every part of the planet but it may not be the optimum orbit if you're not interested in the poles or you're using instruments that don't need to look straight down.