I have been trying to build a ship capable of going from the surface of the Mun up to my orbital station in orbit around the Mun and back down to the surface where my mining operation is. It has to carry as much fuel as possible (~6K in LFO & 1500 in Mono). I've made a dozen variations of ships that are capable of going up into orbit and back to the surface with full tanks. The problem arises when trying to rendezvous with the station. I set up a rendezvous maneuver with the station so there's less than 1.0 distance of separation between the 2 ships at closest approach. Every time after finishing the maneuver, the separation distance starts at 1.0 or less but increases over time. No matter how many maneuvers I do, the distance at closest approach keeps slipping further away. I've even tried a fueling ship that I've successfully used in the past to dock with the station. I just put some wheels on it and put it down on the surface, but it won't rendezvous with the station after lift off. Does any one have any suggestions as to what might be going on? I've never had the separation distance change after a maneuver like this. All my other types of ships (rockets, refuelers, station components, or small science landers) have no problem making rendezvous', just these darn SSTO's.