The National Air and Space Museum of the Smithsonian Institution is a museum in Washington, D.C., in the United States, dedicated to human flight and space exploration. Established in 1946 as the National Air Museum, its main building opened on the National Mall near L'Enfant Plaza in 1976. In 2023, the museum welcomed 3.1 million visitors, m…The National Air and Space Museum of the Smithsonian Institution is a museum in Washington, D.C., in the United States, dedicated to human flight and space exploration. Established in 1946 as the National Air Museum, its main building opened on the National Mall near L'Enfant Plaza in 1976. In 2023, the museum welcomed 3.1 million visitors, making it the fourth-most visited museum in the United States and eleventh-most in the world.