The shuttles were bought and paid for and operated with American taxpayer dollars. They belong to the people. NASA can't "sell" them because NASA doesn't own them. Further, anyone who knows anything about goverment procurement law understands that first rights of transfer belong to other Government agencies. I doubt the National Parks Service, or anyone other than the National Museum of the United States Air force, would have sufficient display capabilities that begin to meet the minimums set forth by NASA. I am convinced that Boeing, Mac-Douglas, or any other civilian operative would not qualify to even think about getting one of these taxpayer-owned beauties. Maybe Canada should put in a bid- it was the CANADAIN Maneuvering arm that did most of the actual work...