scope:

Practice:

Perform thermal dwell test on protoflight hardware over the temperature range of +75°C/-20°C (applied at the thermal control/mounting surface or shearplate) for 24 hours at the cold end and 144 to 288 hours at the hot end. Note: Thermal dwell testing is the standard practice at JPL for systems and components which do not thermally cycle during flight. For systems and components that do thermally cycle (generally over a range greater than 20°C) in flight, the JPL practice is to cycle over a conservative range for three times the number of flight cycles.