Steven F. Udvar-Hazy Center

Listen for a moment before you look up. The air inside the main hangar has a soft, wide echo. Footsteps carry across the polished floor, and voices seem to rise and drift into the steel ceiling far above. Then lift your eyes. Aircraft hang at every level around you, some close enough to read the rivets, some so high they look like models. It feels less like a museum and more like a flock that someone has paused in mid-flight.

This is the Steven F. Udvar-Hazy Center, the companion facility to the Smithsonian's National Air and Space Museum on the National Mall in Washington. The building on the Mall is elegant, but it has limited space. Many of the Smithsonian's largest aircraft and spacecraft simply could not fit through its doors. So the Smithsonian built a second home here in Northern Virginia, beside Washington Dulles International Airport, where giant machines could finally come out of storage and be seen together.

The center opened to the public in December 2003, close to the hundredth anniversary of the Wright brothers' first powered flight. That timing was deliberate. One century after a fragile wooden flyer lifted off a sand dune in North Carolina, this hangar opened with jets, bombers, and spacecraft under one roof. The space hangar was added a little later, and the collection has kept growing ever since.

The name on the building belongs to Steven Udvar-Hazy, a Hungarian-born businessman who left his homeland as a young man and later built a major aircraft leasing company in the United States. His large private donation helped make this center possible. There is a quiet story here — a boy who loved airplanes, who arrived in a new country as a refugee, and whose name now sits on one of the largest aviation collections in the world.

Now look for a long, black shape low on the floor near the centre of the hangar. That is the Lockheed SR-71 Blackbird, a spy plane built during the Cold War to fly higher and faster than any enemy could reach. Its skin looks almost like dark fabric from a distance. Here is a detail many visitors miss — on its final flight in 1990, this very aircraft crossed the United States from the West Coast to Dulles in a little over an hour, setting a speed record that still stands. It landed just outside these walls.

Not far away, you will find a very different kind of speed. The slender white Concorde, flown by Air France, carried passengers across the Atlantic faster than sound. Notice how narrow the cabin is, and how small the windows are. Travellers paid a great deal for the privilege of reaching New York from Paris in roughly half the usual time. Today the Concorde no longer flies anywhere, and this airframe is one of only a handful that remain on public display.

One aircraft in this hangar carries a heavier story. The polished silver Boeing B-29 Superfortress called Enola Gay dropped the first atomic bomb used in war, on the Japanese city of Hiroshima in August 1945. In the 1990s, plans to display it on the National Mall led to a fierce public debate about how such a moment should be remembered. Here it stands fully restored. Many people pause in front of it in silence, and that is a natural response.

Walk on toward the far end of the building, and the ceiling opens into the James S. McDonnell Space Hangar. At its heart sits the Space Shuttle Discovery. It arrived here in 2012, after the shuttle programme ended, and it flew more missions than any other orbiter in the fleet. Look at the underside. The heat-shield tiles are not uniform. They show patches, scorch marks, and slight colour differences — the marks of real trips through the atmosphere and back.

Around the shuttle, smaller objects tell the story of earlier space travel. Look for the Mobile Quarantine Facility, a silver trailer that looks a little like a camping caravan. The Apollo 11 astronauts lived inside it after they returned from the Moon in 1969, because scientists were not yet certain that the Moon carried no harmful germs. Through its small window, President Nixon greeted the crew. It is one of the most human objects in the whole collection.

Back in the aviation hangar, keep an eye out for a yellow and brown jet with an unusual history. The Boeing 367-80, often called the Dash 80, was the prototype that led to the Boeing 707, one of the first successful jet airliners. Many people believe that commercial jet travel, as we know it, began with this aircraft. Legend has it that a test pilot once rolled it in a full barrel roll over a crowd of industry guests — a story often retold, and one that Boeing's own history accepts.

If you want to see the work behind the displays, find the Mary Baker Engen Restoration Hangar. Large windows look down on the workshop floor, where specialists clean, repair, and rebuild aircraft that may wait years for their turn. Some days you will see fuselages stripped to bare metal, wings resting on stands, and tools laid out in careful rows. It is a reminder that every gleaming plane around you once arrived here worn, faded, or in pieces.

For a final view, take the elevator up the Donald D. Engen Observation Tower. From the top, you look straight out over the runways of Dulles Airport. Modern airliners take off and land in front of you, one after another. Below and behind you, the history of flight rests in silence. Out the window, that history is still moving. It is a rare place where past and present aviation meet in a single glance.

Before you leave, stand once more in the middle of the main hangar and look up. Notice the way the light falls through the high windows and catches the edges of the wings. Listen again to that soft echo of footsteps and voices. Every machine above you was once a bold idea that someone believed could fly. As you walk back toward the doors, and perhaps hear a jet roar overhead outside, remember that flight is still a young human achievement — barely more than a century old.