The Smithsonian’s new $225 million Air & Space Museum still needs $97 million before it starts construction. But “when it’s finished, the center will be the largest construction project in the Smithsonian’s history and the only one built completely with private funds. The main hangar, which will house some 200 aircraft, will be the length of three football fields and 10 stories high. On June 12, the annex accepted delivery of an Air France Concorde. Work is also under way to refurbish another big draw, the Space Shuttle Enterprise. And a newly reassembled Enola Gay, the bomber that flew the missions to Hiroshima and Nagasaki, will be displayed as well.”