Fewer Visit the Air and Space Museum

It's a mystery even for researchers at the Smithsonian Institution: What happened to the huge crowds at the National Air and Space Museum? The estimated number of visitors to the museum plunged to about 5 million in 2006 from a six-year high of 9.4 million in 2003, according to the latest attendance report from the museum complex. And the decline has been far sharper than that of the overall Smithsonian, which includes 18 museums and the National Zoo.

Last year, attendance at what has been one of the world's most-visited museums fell below that of the Smithsonian's National Museum

of Natural History, which features ancient fossils and the Hope Diamond. (Museum officials say this is the only instance in recent memory in which the air and space museum trailed the history museum.)

Peter Golkin, a spokesman for the air and space museum, said officials are not worried. He noted that the museum is still the most popular overall.

One explanation for the downturn could be that the museum hasn't opened a major new gallery since 2003. Jason Hall, spokesman for the American Association of Museums, said a museum's "novelty factor" is important in attracting visitors, and it can help explain sudden increases and downturns in attendance.

For the air and space museum, 2003 happened to be a banner year. The museum _ home to the Wright brothers' first airplane and relics from the space race and Apollo moon walks _ had special events in 2003 about the 100th anniversary of powered flight and tragic fate of the space shuttle Columbia.

But the museum could use some freshening up, according to some visitors.

Allen Witt, an engineer from Cedar Rapids, Iowa, said many of the displays seemed to stop after the mid-1980s.

Still, he said, "I don't think this museum will ever lose its relevance. It will get more historic through time."

Construction near the museum may have also kept some visitors away, officials said.

"They've had extensive construction outside for a couple years ... which made it look as if the museum was closed," Smithsonian spokeswoman Linda St. Thomas said.

Another possible factor in the decline could be the museum's annex _ the Steven F. Udvar-Hazy Center _ which opened in Chantilly, Va., in 2003. The massive annex, built like an airplane hanger and located near Washington Dulles International Airport, houses the "Enola Gay" B-29 bomber that dropped the first atomic bomb, the prototype space shuttle Enterprise and dozens of other planes.

The newer facility drew 1.6 million visitors in 2004, its first full year of operation, and about 1 million last year _ visitors who might be ignoring the annex's sister museum in Washington.