Landing on Eve for the first time. I was running out of fuel, and I was sure that I didn't have enough to do more than perform a fly-by. Having spent a few hours on the mission though, I decided to give it a shot. Lo and behold, I managed to perform an aerobrake maneuver and eventually land. I finished with about 13 units of fuel left, and needless to say, I was quite pleased with myself.