TABLE OF CONTENTS Thermal verification tests are of two varieties, those dedicated to confirming the validity of thermal control and those devised to affirm components' integrity and workmanship as individual units and at the satellite level. In the validation test, the input is a predetermined heating load (usually satellite power and simulated orbital fluxes) with temperature as output to be compared and evaluated relative to predictions. The input in the workmanship test is a temperature level (and, consequently, a thermal stress) that usually exceeds the expected value in normal operation, and the output is performance and survivability under short-term but extreme conditions. Workmanship tests are intended to screen out flawed components and project reliability in normal long-term orbital operation.
Test requirements vary, depending on the particular program and acceptable risks. But there is general agreement that thermal testing is more revealing when done in a vacuum, as the absence of heat transfer by convection is likely to lead to results similar to those that would be encountered in space.
For standards on definitions, methods, and levels of heating and cooling, Military Standard Specifications MIL-STD-1540-B [1] and companion document MIL-STD-340 [2] are considered a starting point, although many of the documents' requirements relate to a time when lesser quality parts and materials were being used and serious discrepencies were frequently observed between predictions and actual performance. For many NASA programs, the 1540-B is viewed more as a guideline than a set of rules demanding strict adherence. NASA's procedures for testing...
