For a semiconductor laser, a stacked member comprising an active layer is formed on the surface of a GaN single-crystal substrate, a defect aggregation portion is formed on the rear face of the GaN single-crystal substrate, and an electrode is formed so as to be electrically connected to the defect aggregation portion on the rear face. The system measures the liquid dispensed from a container using a pressure transducer. The propulsion system controller varies the operating conditions of the electric motorgenerator during and engine cranking sequence.