A thermal management system for a directed energy weapon includes a first heat exchanger thermally coupled to the directed energy weapon and a second heat exchanger arranged in fluid communication with the first heat exchanger to form a closed loop. The second heat exchanger is thermally coupled to a secondary system and a thermal management fluid circulates within the closed loop. A thermal storage device is arranged in fluid communication with the first heat exchanger and the second heat exchanger. The thermal storage device contains a material and a mode of operation of the directed energy weapon is dependent on a condition of the material in the thermal storage device.