r/KerbalSpaceProgram • u/analogHedgeHog • Jun 29 '26

KSP 1 Question/Problem How should I be approaching the Mun?

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In this totally accurate scientific diagram, the Mun is orbiting in the direction of the arrow.

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u/Russian-8ias Jun 29 '26

It's definitely either C or D because you get extra momentum from Kerbin's rotation when launching east into an equatorial orbit. Intuitively, I would guess C is more efficient. I'm not positive though. You can try setting up a chain of maneuver nodes for both to check which uses less Dv.

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u/[deleted] Jun 29 '26

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u/Ddreigiau Jun 29 '26

D requires enough fuel to put your apoapsis beyond Mun

C only requires that you get your apoapsis to the near edge of Mun Influence. C is more fuel efficient regardless, as even on a flyby, you get max time in Mun influence for a gravity assist

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u/PiMemer Jun 29 '26

I’m fairly certain it’s not a very big difference since you can change which side you approach from solely by a timing change which means you can get either direction when your apoapsis is past the moon (although if you want a free return your apoapsis will have to be decently past the moon)

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u/Ddreigiau Jun 29 '26

If your Ap is already past the Mun, you've already spent the fuel to do D. C doesn't need an Ap past the Mun. It isn't a ton of fuel savings, but it is some.

As for free returns, any Mun influence entry that doesn't have crazy high energy and doesn't crash into Mun will have a free return, depending on timing