Here is something to consider. How about trying to get to Mun or Minmus, without achieving orbit.
The Challenge is... to get to the mun or minmus without orbiting.
This means that you can not have ny stable orbits. You cant orbit kerbin or mun or minmus. It must all be sub orbital
Normal Mode: Just get there
Hard mode: Get back
Very Hard Mode: Impress me
You need proof via video or pics. No hyperedit of alt+f12 . It must be stock and mechjeb is allowed. If there are any other mods that you think would be fair please tell me about it and i will consider adding it.
Have fun and good luck