Hi guys, I started trying various designs of spaceplanes and SSTOs recently, and became quite comfortable with my ability to get something to LKO and something else back to the spacecentre in one flight. The next logical step is building a plane capable of refueling and going to other planets. However, I have no idea how planes behave in other environments - Duna has lower gravity, but very thin atmosphere, which I suppose will make flying much more difficult, and Eve the other way around - lots of gravity, but a thick atmosphere which could produce much more lift. What is your experience? Does the design have to be much different, and if so, how? More/less fuel to get to orbit, more/less wings needed to fly and land, more/less thrust to takeoff? Thanks, michal.don