Credit: Bill Taub, NASA
Operating transonically or across the speed of sound, the air in the test section travels from about 150 to 1,000 miles per hour.
![Image](http://www.nasa.gov/images/content/431131main_WndTunl_GPN-2000-001918-4x3_800-600.jpg)
Operating transonically or across the speed of sound, the air in the test section travels from about 150 to 1,000 miles per hour.