BALAD AIR BASE, Iraq - Staff Sgt. Thomas Sylvester, 332nd Expeditionary Security Forces Squadron, marks the point of impact with a global positioning system locator after a simulated indirect fire attack during a training exercise here Sept. 28, 2007. Air Force space operators utilize advanced GPS satellite capabilities to provide Airmen on the ground the tools they need to complete specific combat objectives. (U.S. Air Force photo/Staff Sgt. Joshua J. Garcia)