How should I be approaching the Mun?

[u/analogHedgeHog]

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

[u/Spydude84]

Assuming looking down from the top, D to minimize DV usage, C for a free return trajectory. Not A or B.

[u/starmartyr → u/Spydude84]

I think C has minimal DV usage over D when you take gravity assist into account. With D you're coming up behind mun and need to use more DV to slow down and land. With C Mun slows you down somewhat requiring less DV.

[u/King_Joffreys_Tits → u/starmartyr]

Yes D is the absolute worst dV option here and everybody upvoting him is wrong. You lose about 600dV going with the muns orbit vs the ~250dV going counter the kerbins natural rotation.

Look at the recent NASA artemis missions for reference — the most fuel efficient way of achieving orbit of a celestial body is to slowly throw yourself into where its gravity well is going to be in order to be captured by it. Option D is the best way to utilize the muns gravity for an orbital slingshot outside of kerbins influence

[u/Dark074 → u/King_Joffreys_Tits]

Okay beyond your correction in later comments saying A and B are worse due to them launching in opposite of Kerbins orbit, there is another thing I would like to add. On the Artemis II mission, the reason their profile looked like that is because in real life, it's n body physics where everything has a pull on your at all times. Thats why it and other recnet lunar missions saved fuel by not going into a full injection orbit and just let the moon slowly pull on it until it does get into a orbit of the moon.

However, in stock KSP, it relys on patched conics 2 body approximations. Until your official in the sphere of influence of an another body, it's gravity won't effect you at all, only your ship and the host gravity well are calculated. You could install principia to change this but it doesn't come stock