I had a ship orbiting Minmus, freshly fueled and ready to head to Duna. However, there doesn't seem to be a maneuver in the planner for heading from a moon to a different planet. 'Hohmann transfer' only works to transfer between orbits in the same sphere of influence, 'transfer to another planet' only works when you're in the sphere of influence of the planet itself, and 'return from a moon' doesn't do anything if you try putting in a periapsis anywhere near the moon's orbit.

What I'd like to see is an 'escape SoI' maneuver, which would plot the minimum burn needed to escape your current sphere of influence. Used around Minmus, it would leave the rocket orbiting Kerbin (in an orbit similar to Minmus's, I suspect). Around Kerbin, it would put the rocket orbiting the sun, and around the sun it would put the ship on a course out of the system. By using this to leave Minmus's sphere of influence, I could then use the planetary transfer to head to Duna.

Of course, there may be a more efficient way--enhancing the rendezvous planner to handle going from any object to any object would be very cool--but I think an 'escape SoI' maneuver would be useful.

ReturnFromMoon is probably the right approach to this problem. Due to Oeberth you do actually want to drop your periapsis around Kerbin before ejecting to the other planet. The exact optimal ejection would be difficult to determine though without adding support to AdvTransfer to handle ejection from a Moon SOI combined with an ejection burn out of Kerbin.

You might try the "return from a moon" maneuver; this may accomplish more or less what you are looking for.

I don't want to enter an orbit around Kerbin with a periapsis of (say) 100 km. I want one somewhere around 11 Mm (i.e., a minimal burn to get out of the Mun's influence), and as I said, 'return from a moon' refuses even to plot that burn.

Ah; sorry, I didn't read carefully enough. I think the right thing to do is for us to try to get "return from a moon" to work for such orbits. I'll try to look into it at some point.

Related to #1051. If we could support "advanced transfer to another planet from a moon" in #1051 then that would close this issue. To solve the problem via a "just escape from the SOI" maneuver an issue to solve would be "which direction do you want?" i.e. the desired ejection angle.

It is possible this would be useful for players anyway even apart from transfer planning, so leaving this open.