Abstract: The spacecraft in deep space exploration missions faces a harsh environment of radiation and temperature variations, and the CMOS integrate circuits, as the principle part of the electrical components, are vulnerable to the potential single event latchup. In view of the inflight application requirements, the single event latchup experiments for the SRAM device fabricated by the bulk silicon process under different electrical and thermal stresses are carried out with the heavy ions ofvarious LET values. It is shown that under thesame thermal stress, the single event latchup sensitivity increases with the rise of the operating voltage. While under the same voltage condition, the crosssections of the single event latchup increase by about one order of magnitude with the increase of the temperature. The temperature dependency of the single event latchup remains the same for different ion radiations. It is concluded that the single event latchup may be more easily triggered at higher temperatures and higher operating voltages.