I made this a while ago, but the much much longer and detailed story was lost in the devastating forum crash. It's a regular space plane, but with a twist. I made it, because I wanted to go to Laythe and fly around there. It took a lot of developing and trial and error. I'll keep the story short: On the runway, ready for its flight to Laythe. After some burning, and aerobraking around Jool, it has arrived at Laythe and docked with a station. You can see the "twist". It takes off with a standard liquid engine, swaps it for a NERVA in Kerbin's orbit, and swaps it back for a regular liquid in Laythe's orbit. Flying around Laythe. Back on Kerbin, it can get rid of the now unnecessary engine module... ...and head for KSC.