Why is the idea of putting a station in orbit more appealing then putting on on the moon? I understand the want to test things in low gravity. But what about cost wise? I know that the ISS has to change it's direction every now and then to avoid random junk floating in space, and I understand it would take more fuel to get something to the moon. Is there anything more to the equation then this or is it just that the cost of getting something to the moon and back is much more expensive then maintaining an orbital station? Thanks for your time.