Speadge, Thanks for the hints. I have Kerbal Engineer installed, but the biggest problem I have is building rockets that don't lose so much Delta-V when adding more stages. As an example, I had a rocket with a 4.7t payload (space station). I added the first stage with the Rockomax X200-32 and the "Skipper" engine. I think that had around 3100 dV. I added a second stage with the only difference being the engine -- the "Mainsail" -- and the total dV was just around 4000 dv. The more I played with it, the less productive the rocket was. I was able to get a rocket with around 6000 dV, but I hit my weight limit of 140t. I'm still working it out -- perhaps I'm just taking too much "junk" to the Mun on each trip.