HOLLOMAN AIR FORCE BASE, N.M. -- Members of the Physiological Training Center concluded 22 years of centrifuge training at Holloman Air Force Base, N.M., with its final spin Oct. 27, 2010. Operated by the U.S. Air Force School of Aerospace Medicine, the centrifuge was used as a training device to expose pilots to a high level of G-forces -- a measurement of an object's acceleration -- which aircrews encounter in high-performance aircraft. Upon its last spin, Holloman's centrifuge had been used to train nearly 32,000 students, including service members from all branches, North Atlantic Treaty Organization troops and members of allied forces. (U.S. Air Force photo by Senior Airman Veronica Stamps)