Refuelling Munar Station in polar orbit - HELP

[Delta-Cheese]

WARNING: Bad english ahead

OK, my munar station in a polar orbit is out of fuel. Great...

I have tried every single design possible but nothing works. While in orbit of the Mün the delta-v for a plain change is HUGE, and I can't for the love of cheese get a manneuver that adjusts my plain while in the SOI of kerbin... Any ideas? I would like to deliver at least 1/4 of an orange tank at a time. BTW this is career mode and I have not unlocked spaceplane tec, but I have all 2,5m parts. If you could post me some designs it would really help.

[Xuixien]

Best way to refuel would be to have a ship that land son the mun, mines, processes ore to fuel, and takes off.

[Kobymaru]

Yeah, you can't practically change the plane from equatorial to polar in one burn.

However, if you burn out to the edge of the Mun SOI, do the plane change there, and then burn back, you actually use *less* dV. About 600 m/s if I recall correctly.

If you want to do a direkt KSC launch, you do the following

- Launch like you would go to the regular orbit

- Get an intercept, but one where the apoapsis of your trajectory crosses the muns trajectory

- Halfway between Kerbin and the Mun, place a maneuver node

- Focus the Mun, but in such a way that both your trajectory and the maneuver node are visible

- Pull the maneuver node "up", which would be the "normal" direction until the trajectory is clearly above the pole

- Play with the Prograde and Radial component of the node to move your trajectory directly over the pole

- Over the pole, create a maneuver node that captures you in Mun Orbit. Do NOT circularize! The more elliptical your trajectory is (without leaving the Mun SOI), the better

- Do all the burns, arrive there

- At the Apoapsis (which should be far out now), create a node for a plane change. Note that this doesn't change the Inclination, but the "Longitude of Ascending Node" or whatever, but

- If you set the fuelless station as target, you can now easily burn at the (relative) ascending or descending node, whichever is at the Apoapsis which is still far out. This should take super little dV (less than 30 m/s)

- Once you matched the plane, you can lower the apoapsis. If I were you, I'd use the opportunity to find a rendez-vous, by placing the maneuver for the burn slightly *after* the Closest approach marker. This way, you should see the "Target Position at Closest Approach" marker rotate around when you drag the retrograde maneuver vector. Use this to align the two markers.

[Snark]

Good explanation from Kobymaru. The summary is: Getting into a polar orbit around the Mun (from Kerbin) isn't really any more expensive in terms of dV than getting into an equatorial one. The key is that you aim for a polar orbit from the get-go. Don't go to the Mun in an equatorial orbit first and then try to change your plane.

Xuixien's strategy is also good, as long as you can land a miner on the Mun straight from Kerbin. From a surface-landed ship, it's as easy to sync up with a polar station as it is with an equatorial one-- you just have to wait until the Mun rotates your position so that it's under the station's orbit.

[Delta-Cheese]

- Pull the maneuver node "up", which would be the "normal" direction until the trajectory is clearly above the pole

- Play with the Prograde and Radial component of the node to move your trajectory directly over the pole

This is what I can't do, it never lines up with the pole. Is it just me being stupid? Either way how do I do all of this while still having fuel left?

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Best way to refuel would be to have a ship that land son the mun, mines, processes ore to fuel, and takes off.

I don't have mining tec yet...

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Simple plan, send another station up and deorbit the current one. Full Fuel and getting rid of old tech!

Well... deorbiting that is kinda impossible because it has no fuel, and it has a bunch of things docked, a lab, lander, crew modules so I really don't want to redo it.

[ForScience6686]

Since you don't have mining tech, just send a bunch of tanks with a probe core. Either leave the tanks attached for extra fuel storage later or leave enough fuel to de orbit and crash into the mun.

[ForScience6686]

I would also not recommend polar orbit for stations. My solution involved a station in an equatorial orbit and a tug in a polar orbit that my science hopper would rendezvous with for refueling. The tug would then bring the hopper and crew back to the station.

[Nothalogh]

Make the inclination course correction before capturing into orbit around the mun

[FlyingPete]

Make the inclination course correction before capturing into orbit around the mun

This is basically it. Aim for a Mun intercept that results in a collision course with the Mun. As the ship enters Mun SOI, make a plane change burn while you're as far as possible from the Mun. This is the most effective way of lining yourself up in a polar orbit. One complication is that you need to approach the Mun from the right angle- you can otherwise end up in a polar orbit that's still 90 degrees out.

[Delta-Cheese]

Ok, I was able to refill it... but I am still rather confused on how to do this.

[Randazzo]

The problem with polar orbits is that the orbiting vessel will always be orbiting in the same relative plane around the Mun, but the Mun is constantly moving relative to Kerbin making hitting the exact same orbital plane very difficult since it's position is always moving. This is not to mention your fuel transport may not be in the right place at the right time to hit the appropriate transfer. I think it'd be safe to say there is no easy way to do this without a plane change at the Mun.

Doing a direct launch at precisely the right time might work, but I imagine that'd be exceptionally complicated to get right.

[EdusacconBR]

Fly to there like you would do in kerbin