May 1, 1997 - The first Next-Generation 737-700 takes a moment from its busy flight-test schedule to pose for a picture with the original 737 at the Museum of Flight in Seattle, Wash. The first 737 returned to its birthplace in Seattle for a one-day exhibit sponsored by the Museum to commemorate the 30th anniversary of the airplane's historic first flight. The original 737 was purchased by the National Aeronautic and Space Administration (NASA) from Boeing in 1973 and continues to be used by the space agency to conduct weather research. Since the original 737 first flew on April 9, 1967, mire than 3,600 have been ordered by the world's airlines, making it the most popular jetliner in commercial aviation history. The sales pace for the Next-Generation 737-600/-700/-800 models has set an aviation sales record with 535 airplane orders from 26 customers. The first Next-Generation jetliner will be delivered to Southwest Airlines in October.