Back in 2004 I visited the new Steven F. Udvar-Hazy Center near Dulles Airport in Chantilly, Va., a branch of the National Air and Space Museum. One of the major displays was the space shuttle Enterprise, which was used for unpowered test flights in the 1970's. On April 27, 2012, I happened to be in lower Manhattan as the Enterprise flew (on the back of a 747) up the Hudson River on its way to Kennedy Airport and eventual permanent display at the Intrepid Museum in New York. The Enterprise is being replaced in Virginia by the shuttle Discovery.