Taking part in US Joint Forces Command's Empire Challenge 09, Northrop Grumman demonstrated that crews aboard USAF E-8 Joint STARS ground surveillance aircraft could receive unmanned aerial vehicle sensor imagery, analyze it, and add it to the Global Command and Control System. A Navy E-2C Hawkeye then utilized the UAV target imagery and Joint STARS ground tracking to direct strike aircraft. According to Northrop's Aug. 24 release, "the net effect of this ISR sensor tasking and command and control network was a reduction in both the kill chain—the time it takes to find, identify, and engage a target—and the operator workload required to accomplish the task." Northrop said it used "virtual physics-based and operational flight program simulations" for the E-8 and E-2 manned platforms and other aircraft.