Polar orbits

[KvickFlygarn87]

I have launched a scanner sat to Laythe, where I'm building a colony. However it is not in a polar orbit, but in a 29^o orbit. How would I go through with making it polar as efficient as possible?

Edited December 23, 2013 by KvickFlygarn87
Added clarificaton

[maccollo]

You could just do a planeshift.

You could raise your orbit and then do the planeshift.

You could escape Laythe, encounter it again, and come it over the poles.

[KvickFlygarn87]

You could just do a planeshift.

You could raise your orbit and then do the planeshift.

You could escape Laythe, encounter it again, and come it over the poles.

Thanks for explaining in such a detailed manner!

I need a guide on what's the most efficient way to do it.

[Grover]

best efficiency comes from raising your apoapsis as high as possible, then burning normal or antinormal at your new apoapsis to change your inclination to 90* or 270*, then lower your apoapsis down again

however, your satalites are usually best used at high altitudes (for the high res ones anyway, so you could just leave it up high, using even less dv

[KvickFlygarn87]

best efficiency comes from raising your apoapsis as high as possible, then burning normal or antinormal at your new apoapsis to change your inclination to 90* or 270*, then lower your apoapsis down again

however, your satalites are usually best used at high altitudes (for the high res ones anyway, so you could just leave it up high, using even less dv

Actually, first of all I don't know where to do my plane change, second of all I'm not using a map sat, I'm scanning for ore/kethane and my Magnetometer requires me to be below 60000m.

[FenrirWolf]

There are a few ways you can approach the problem. The simplest, but probably most costly maneuver would be to burn at the ascending/descending node until your inclination goes to 90.

If you want to try something that might or might not save fuel, see if you can burn out to a Vall or Tylo encounter, then use the resulting slingshot to reencounter Laythe at a more favorable angle to turn into a polar orbit. Maybe you could get a little help from Jool too.

No guarantees that would save you any fuel, but it's worth a shot and would be something fun to do either way.

[longhornchris]

Any plane change requires burning normal to your orbit plane. The higher you are, the slower you are and thus it takes less dv to get the right inclination but it takes 3 burns unless you are also trying to get to a high orbit anyway.

Without doing math it's tough to figure out the most efficient way, but the general approach is to raise your equatorial node (where you cross the equator) nice and high. Next do the plane change at the apoapsis node. For large plane changes it may take a few burns. Finally lower your orbit back to the desired orbit.

[KvickFlygarn87]

Any plane change requires burning normal to your orbit plane. The higher you are, the slower you are and thus it takes less dv to get the right inclination but it takes 3 burns unless you are also trying to get to a high orbit anyway.

Without doing math it's tough to figure out the most efficient way, but the general approach is to raise your equatorial node (where you cross the equator) nice and high. Next do the plane change at the apoapsis node. For large plane changes it may take a few burns. Finally lower your orbit back to the desired orbit.

Thanks! But how do I tell where the eq node is?

[Stargate525]

Once you reach your AN/DN (unless you've got a mod, you'd got to eyeball it anywhere but Kerbin), turn north/south: south if you're going down, and north if you're going up. Keep your indicator on the navball's horizon, and slide along it until the prograde and retrograde markers flash back and forth on the far extremes of the navball.

If you burn at this point, your orbital velocity shouldn't change. You'll have to keep nudging along the horizon to keep yourself pointed properly, and you'll be polar once you're pointing either 90 or 270.

Hope that made sense!

[Smidge204]

Burn prograde at Pe to get your Ap as high as you can (3,723,000 meters max or you'll leave Laythe entirely) or as high as you can with the fuel you have, leaving enough to do the orbit adjust and recircularize.

Put a node at your new Ap and tweak the purple handles until your orbit is how you want it. Ideally, some combination of the purple (normal/antinormal) and green (prograde/retrograde) will be used to keep your Pe the same while rotating the orbit... mostly retrograde.

Execute node.

Burn retrograde at Pe to lower your orbit again.

Done!

You won't get Ascending/Descending nodes unless you have something targeted for a reference, so you have to kind of eyeball it using the navball.

=Smidge=

[KvickFlygarn87]

Thanks Smidge! Are there any mods that enable you to see the eq node on map screen?