An historic day in Washington — Discovery's final flight

NASA Space Shuttle Discovery arrives at Dulles International Airport. Photo by John Bretschneider/Staff

The space shuttle Discovery flies her last mission over Washington DC. before landing a Dulles International Airport where the shuttle will then go on dispay at the Smithsonian April 17, 2012 in Washington DC. Thomas Brown/Staff

Spectators at the Washington Monument watch as space shuttle Discovery flies her last mission over Washington DC. before landing a Dulles International Airport where the shuttle will then go on dispay at the Smithsonian April 17, 2012 in Washington DC Thomas Brown/Staff