Today I finished the flight of my single person, 1.25m Duna lander. I was inspired by a thread here of somebody else working on a similar design. I wanted to combine an Apollo style lander where the descent stage engines are discarded before liftoff, plus I've only ever done cylindrical landers with a single engine and wanted to try something new. The idea was that the three outboard engines would be used to kill velocity in the final stage of the approach. On liftoff, the three pods detach and the central engine lifts the capsule back to space. In the end, I had so much fuel left in the landing engines that I used them for the beginning of the liftoff. The separation still looked cool though.