That's how we're supposed to do this, right?  ... Right?  ...  Oh well, too late.  That's how I did it. With one launch, I flew a 300t payload to Minmus, and then flew that same payload to Duna. All screenshots:  https://imgur.com/a/120d8Bt Highlights: Launch to LKO More:   LKO to Minmus landing Minmus back to LKO LKO to Duna landing Burning for Duna More:   By the way, I landed 20.2km from the landing location