CHANTILLY, Va.—The Smithsonian National Air and Space Museum’s better-known flagship facility on the Washington Mall draws the most visitors, but a vast building near Dulles Airport houses far more planes and other aviation artifacts.

Two adjoining hangars at the Steven F. Udvar-Hazy Center hold the space shuttle Enterprise, 150 other major spacecraft large and small, a Concorde supersonic jet and about 160 other aircraft, some dating to the early days of flight.

“You walk around here and you think about all the stories that are in the artifacts,” public affairs specialist Frank McNally said.

The Virgin Atlantic GlobalFlyer that Steve Fossett piloted in the first non-stop, jet-powered solo flight around the world is on display, along with the Double Eagle II, the first balloon to transit the Atlantic.

“There’s the airplane that a guy pedaled across the English Channel,” McNally said. “Obviously, the guy was a bicyclist.”

Goodyear’s first blimp gondola, the Pilgrim, which first flew in 1925, is there. So is “Wendy,” FedEx’s first plane, a Dassault Falcon 20 that’s all cockpit and cargo bay and began service in 1973.

“This is probably the most famous airplane ever built,” McNally said as he stopped in front of the Enola Gay, the B-29 that dropped the atomic bomb on Hiroshima, Japan, on Aug. 6, 1945.

The museum has a number of German and Japanese planes from World War II, including a Japanese Aichi M6AI Seiran, which has wings that fold up, a tail that folds down and pontoons that come off so the plane can fit into a tube in a submarine.

Young visitors might be more interested in the Lockheed SR-71 Blackbird, the world’s fastest plane, which is seen along with the museum in a new movie, “Transformers: Revenge of the Fallen.”

The space artifacts include the Gemini VII capsule, which flew into space in 1965 and looks far too tiny to hold two space-suited men, and a mobile quarantine facility, a converted Airstream trailer that confined the Apollo 11 crew for 65 hours, until scientists were sure the astronauts were not infected with “moon germs.”

The Udvar-Hazy Center opened in 2003. It was designed by Hellmuth, Obata and Kassabaum, the St. Louis-based architecture firm that also designed the Air and Space Museum on the National Mall. Elevated walkways bring visitors close to many of the aircraft.

A 164-foot-tall observation tower provides views of nearby Dulles Airport and contains a mock-up of a flight-control tower, and an IMAX theater offers a selection of movies.

An expansion with space for a restoration hangar, archive facilities and storage is under construction and expected to be completed by October 2010. (A national development program continues to raise funds for the work.)Ultimately, museum officials say, the Udvar-Hazy Center will display 80 per cent of the air and Space Museum’s collection; the Mall building has space for only 10 percent.

If you go

Getting there: The best way to arrive is by car, although a shuttle bus runs from nearby Dulles airport.

Address: 14390 Air and Space Museum Parkway, Chantilly, Va. (near the intersection of Route 28 and Route 50 in Northern Virginia).

Cost: Parking is $15. Admission to the center is free, but there is a charge for IMAX movies and other activities.