A two month cruise the to moon and back, for a total cost of under 10 million dollars. It involves, of course a test mission, to prove that it's safe. A giant hot air balloon, or even a series of them, from horizon to horizon, supporting a spring board platform, on top is a deep water submersible inspired design, like a bubble, or an egg, completely protected from radiation, with a green house, and pressurized air jets for navigation. Get high enough to eject beyond the atmosphere, possible jet propulsion to help, then float around the moon and back. Simple.