This is a beautiful souvenir sheet, issued in 1999, honoring NASA's Mercury Seven space astronauts and commemorating the first flight of the Concorde aircraft. Featured astronauts include Alan Shepard, Gus Grissom, John Glenn, Scott Carpenter, Wally Schirra, Gordon Cooper, and Deke Slayton. The sheet is fresh, mint never hinged, and F/VF.