The space shuttle Dicovery nside the Udvar-Hazy's James S. McDonnell's Space Hangar. (Photo by Tracy A. Woodward/The Washington Post)

3 How many football fields could fit inside of the Boeing Aviation Hangar, which displays three levels of artifacts. These levels include aircraft hanging from the arched ceiling, along with engines, helicopters and experimental flying machines on display in a museum setting for the first time.

66 Height in inches of the 1960s android used to test space suits. The dummy allowed scientists to perform experiments that might have been painful, tedious or even dangerous if they had been performed on a human being.

152 Large space artifacts housed in the James S. McDonnell Space Hangar. Some of the highlights include: the space shuttle Discovery; the Gemini VII space capsule; the mobile quarantine unit used upon the return of the Apollo 11 crew; and a short-range surface-to-surface Redstone rocket.

360 View in degrees from the observation tower, providing a bird’s-eye view of Dulles International Airport and the surrounding area. Visitors can watch planes take off and land and view two levels of exhibits explaining how the U.S. air traffic control system works.

2,124 Miles per hour the Lockheed SR-71 Blackbird averaged on its 1990 record-breaking flight from Los Angeles to Washington. (The total flight time was 1 hour 4 minutes 20 seconds.) The Blackbird is the world’s fastest jet-propelled aircraft and is one of the museum’s most well-known artifacts.

22,039 Tiles on the space shuttle Discovery. The tiles acted as a heat shield during flights and were carefully inspected for damage after each mission.

300,000 Hours put into restoring the Boeing B-29 Superfortress Enola Gay, perhaps the museum’s most controversial artifact. The aircraft — the most sophisticated, propeller-driven bomber to fly during WWII — was used to drop the first atomic bomb used in combat on Aug., 6, 1945, on Hiroshima, Japan, and flew weather reconnaissance three days later when a second atomic bomb was dropped on Nagasaki. The Japanese surrendered on Aug. 14, 1945.