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.