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Question about putting a satellite in a polar orbit on Mun


SignalCorps
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I have a contract to put a sat in polar mun orbit, and after much failure trying to start from a polar orbit on Kerban (Mechjeb doesn't much like polar Hoffman transfers, and even when I do it on my own, I don't arrive on the correct polar plane) I just started on a 0 degree orbit and figured I'd sort it out once I got there.

I got into a stable equator orbit and after much thrusting and cursing, I got myself pretty damn close to the indicated orbit. Ap was listed 181km and I was at 180 (Per is about the same margin), I don't really see how to check my inclination in the standard game, but Mechjeb lists me at 90.076 (contract asks for 90) and my orbit looks dead on to the indicated contract line. But it's not completing. I have a checkmark for everything but "reach the designated orbit". Then I noticed the little swirling dots on the indicated orbit are going the opposite direction I am. Does it really matter if I am orbiting counter-clockwise and the indicated orbit is clockwise (at least from how I am looking at it currently)?

And is there a better way to go about putting sats around other bodies at odd angles?

Edited by SignalCorps
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>Does it really matter if I am orbiting counter-clockwise and the indicated orbit is clockwise (at least from how I am looking at it currently)?

It really does. Hover the AN/DN node see whether you see 0 degree or 180 degree. If 180 degree, you're going backwards. In this case, the displayed inclination value doesn't even tell you anything because it will be 90 in any case - you really need to see AN/DN node.

And the best way for polar orbit on Kerbin is to directly shoot polar orbit rather than correcting after getting equatorial. I believe former is like 300m/s penalty while correction from equatorial will take at least 1.5km/s

Putting to polar orbits on another celestial body is another completely different process - mid-course maneuver gives you just additional 10~50m/s depending on the size of the target planet. That's way easier.

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One thing i can say is to create and equatorial LKO orbit. Transfer to the mun. Make a very high mun orbit. Since the delta v required to change your plane to a polar orbit is roughly equal to your orbital velocity you should make your plane change high over the mun (where your orbital velocity is low). From there you can reduce your orbital height and finish your orbit! Polar orbits always require extra ∆v but how you execute the orbit change is what changes the mission.

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Yes, you need to be going the same direction of the dots. To swap directions optimally you will need around you perapsis velocity in dv remaining.

Swapping orbit directions:

- At peri, burn prograde to raise your apo to right before the SOI edge

- At apo, burn retrograde for 2x you apo velocity to swap your orbit direction

- At peri, burn retrograde to lower your apo back to its original value

Next time set up the polar, prograde, or retrograde orbit before you enter Mun's SOI or at the latest just after you enter its SOI.

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Oh sorry I missed that you already said Mun polar orbit. What I said earlier still applies, but I can give more detail.

In this case, the least dV way is - launch equatorial, maneuver intercept when the desired orbit aligns with your ejection direction (usually when the line between Kerbin and Mun is on the satellite orbital plane), then put mid-maneuver node to make you eject into a polar escape path (be careful that whether you go normal or anti-normal depends on the direction you want to go), then you just circularize at Mun periapsis and should be a small inclination adjustment around Mun.

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For a non specific polar Mun orbit I usually set up regular Mun transfer but with a Mun impact trajectory rather than a low periapsis, then when I'm about half way to the Mun switch focus view onto the Mun and do a small burn normal or anti-normal to align the orbit to above or below the Mun. If I have to match a specific orbit I'll enter Mun orbit and do the usual high apoapsis plane change.

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