Skip to main content

Space History Photo: Sci-Fi? No, Snow on Vacuum Spheres

space history, vacuum spheres, hypersonic facilities, Langley
These vacuum spheres housed wind tunnels that were part of Langley's Hypersonic Facilities Complex. (Image credit: NASA.)

What looks like some otherworldly scene from a sci-fi movie is just some vacuum spheres used to simulate hypersonic flight conditions in attached tunnels. In this historical photo from the U.S. space agency, the vacuum spheres, now part of Langley's Hypersonic Facilities Complex, had been dusted by a light fall of snow in 1969.

Here’s how it worked: The spheres would be evacuated to give low starting pressure in the adjacent eight hypersonic wind tunnels, simulating a range of conditions from six to twenty times the speed of sound.

The various tunnels utilized air and certain gasses, including helium and nitrogen, to investigate aerodynamic and aerothermodynamic problems in flights above the speed range of Mach 5, or five times the speed of sound.

Each weekday, looks back at the history of spaceflight through photos (archive).

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at:

The National Aeronautics and Space Administration (NASA) is the U.S. government agency in charge of the civilian space program as well as aeronautics and aerospace research.