A system includes a gas turbine engine configured to provide propulsion to an aircraft and a starter system configured to start the gas turbine engine. The starter system comprises a motor controller and a closed-loop cooling system configured to cool the motor controller during an emergency in-flight restart operation of the gas turbine engine. The closed-loop cooling system includes a cooling fluid reservoir containing cooling fluid. The cooling fluid is configured to receive thermal energy from the motor controller during the emergency in-flight restart operation of the gas turbine engine.