Munar plane changes & rescue

[KocLobster]

Two questions I've had for a while now that I assumed I might figure out on my own eventually (didn't happen lol).

What is the most efficient way of getting home from the Mun if you're either a) in a polar orbit or b) near one of the poles and don't have much choice but to get into a polar orbit (afaik you can't immediately make a equitorial orbit taking off from a pole)? In these situations, the only way I understand how to realisticly return to Kerbin is by ~500dV worth of inclination changes (thereby wasting loads of fuel) to get into an equatorial orbit, and going from there. Is this necessary? If not, what's the procedure for getting back to your celestial main body if in a polar orbit? I don't seem to know where to put my maneuver node; the closest my periapsis usually gets is ~4 million km away.

My other question involves how to rescue a stranded craft on the Mun. Since it's landed, I don't see how using the Klaw is possible (won't matter that it has no docking ports at this point). If I try and get close I'll surely crash. Can you safely go horizontal at that extremely low altitude? I assume no, so I need a refueling rover type craft, right?

Edited March 14, 2016 by KocLobster

[Tyverus]

While not an expert, I'd reason that achieving a kerbin orbit then doing the plane change may be more efficient since you're farther from the celestial body and thereby more efficient. 

Assuming you're not on a modded install, i'd land as close as possible (making sure to have much more dV than necessary) then hover  to the stranded craft. You could hten theoritcally use a claw either on the bottom or the top and carefully claw for the refuel. On a safer note, the rover with a claw would most likely be the most save you could be since it wouldnt really matter how far away you landed depending on the time you watned to drive over.

[Hodari]

You don't need an equatorial Munar orbit or even to get into an orbit at all(it certainly makes planning easier though).  Just fly directly opposite the direction of the Mun's orbit until you're able to escape into Kerbin orbit.  You also don't need to worry about the inclination of that orbit unless you're trying to land back at the KSC(and if you're that low on fuel, this is probably the least of your worries).  Once you're in Kerbin orbit, jsut burn retrograde at apoapsis as usual in order to drop your periapsis to the desired height

As for the stranded craft, if you need to rescue the whole craft, then yeah, refueling rover would probably be the easiest way.  If you just want to save the crew, all you have to do is land the rescue craft anywhere nearby and have the crew EVA over.  They can also collect any science data first, of course.

[KocLobster]

13 minutes ago, Hodari said:

You don't need an equatorial Munar orbit or even to get into an orbit at all(it certainly makes planning easier though).  Just fly directly opposite the direction of the Mun's orbit until you're able to escape into Kerbin orbit.  You also don't need to worry about the inclination of that orbit unless you're trying to land back at the KSC(and if you're that low on fuel, this is probably the least of your worries).  Once you're in Kerbin orbit, jsut burn retrograde at apoapsis as usual in order to drop your periapsis to the desired height

As for the stranded craft, if you need to rescue the whole craft, then yeah, refueling rover would probably be the easiest way.  If you just want to save the crew, all you have to do is land the rescue craft anywhere nearby and have the crew EVA over.  They can also collect any science data first, of course.

Ahhh, I like this. Thank you. I'm not sure why I thought I had to strictly follow what I saw Scott Manley do with returning from Mun. That sounds stupidly easy, not sure why I never tried that. That would save a ton of wasted dV too. Thanks

As for the rescue, that's what I figured. Although I now realize I'd be willing to just EVA->save my kerbal and purposely destroy the craft. Didn't think of that for some reason.

[OhioBob]

To get back to Kerbin from a polar munar orbit, just wait until the orbit is aligned in such a way that, as you pass over one of the poles, your spacecraft is moving in a direction that is retrograde to Mun's orbit.  Then just burn the same as you would if you were in a equatorial orbit (placing your maneuver node at a point that is about 45^o before reaching the pole).  You'll pass over the pole and depart Mun space in a retrograde direction, coming straight back to Kerbin just the same as if you were in an equatorial orbit.  You may have to wait around a day or two for the correct alignment to occur, but that's not a big deal.

 

Edited March 14, 2016 by OhioBob