Comparison of Recent Satellite Flight Temperatures with Thermal Model Predictions

In space vehicle applications, a thermal uncertainty margin, in the form of a temperature adjustment, is added to thermal model predictions to account for analysis uncertainties. As such, it is not so much a safety margin as it is a means of including nominal sensitivities of expected conditions and modifying analytic results for recognized model limitations. The intent of the thermal uncertainty margin for military space programs is to ensure that 95 percent of thermal model predictions are within ±11°C of flight temperatures. Recent flight thermal telemetry was compared to thermal model predictions to assess the continued use of the thermal uncertainty margin.