Zero Gravity Facility at Lewis Research Center, now known as John H. Glenn Research Center at Lewis Field.
Credit: Paul Riedel, Al Lukas
In this historical photo from the U.S. space agency, taken September 12, 1966, the Zero Gravity Facility is seen at Lewis Research Center, now known as John H. Glenn Research Center at Lewis Field. This is a tunnel view looking up from level 5. This tower drops 460 feet and allows scientists 5.18 seconds of zero gravity. By comparison, the Washington Monument is 555 feet tall.
Nowadays of course, zero gravity flights are done on specially equipped airplanes that make parabolic flights for researchers and even tourists.
Each weekday, SPACE.com looks back at the history of spaceflight through photos (archive).