Quite simply, using this: I a test flight which went amazingly well by my standards in that it actually worked as I wanted it to first try, it was capable of achieving orbit, doing a burn powerful enough to inject it to another planet and insert and decelerate, land on Kerbin, take off from Kerbin and returning. So now I just need to wait until they add the new planets to see if it will go as successfully in the actual thing as it did in tests. I also did some testing to see how I could use gravity to assist with my return: I'd spoiler the images but the commands didn't seem to work.