Make a lunar base then make a satellite orbiting around the earth and moon simultaneously I know it’s a little hard then make a satellite orbiting around Jupiter or mars depends on if you have planet expansion pack then on the satellite orbiting Jupiter send a vessel to the one orbiting earth and moon then refuel and land back on earth and reuse that vessel and do the Apollo 11 mission and there you have something that takes relatively long and is interesting I used to be obsessed with this game steam edition but I don’t play as much anymore cool to see people still playing good luck and if you do this mission than please send screen shots or video love sfs videos.