 To sustain the remaining inventory, the ATACMS Service Life Extension Program (SLEP) was launched, which refurbishes or replaces propulsion and navigation systems, replaces cluster munition warheads with the unitary blast fragmentation warhead, and adds a proximity fuze option to obtain area effects; deliveries are projected to start in 2018.The ATACMS SLEP is a bridging initiative to provide time to complete analysis and development of a successor capability to the aging ATACMS stockpile, which could be ready around 2022.In January 2015, Lockheed Martin received a contract to develop and test new hardware for Block I ATACMS missiles to eliminate the risk of unexploded ordnance by 2016.