 On 7 August 2015, the Air Force issued contracts to Boeing, Lockheed Martin, and Northrop Grumman for a one-year pre-engineering and manufacturing development effort to mature and test competing designs ahead of a downselect in late 2017.While the E-8C will begin retirement in 2019, an EMD contract will be awarded for two test aircraft, followed by low-rate production of three aircraft for initial operational capability in late 2023, with the remaining 12 aircraft purchased through 2024.On 2 March 2017, Northrop Grumman announced the submittal of its proposal to the U.S. Air Force for the Joint STARS Recapitalization program.