June 8, 2011
In a USAF centrifuge at Brooks Air Force Base, Texas, U.S. Sen. John H. Glenn Jr. is strapped in by the Johnson Space Center's Carlous Gillis (left) and USAF Tech. Sgt. Mac Baker, a centrifuge mission controller. The STS-95 mission specialist completed two nine-minute sessions in the centrifuge, reaching a threshold of three G-forces, or three times his own body weight. (USAF photograph by Staff Sgt. Steve Thurow).