Downloaded from https://www.everyspec.com MIL-STD-81OC 1,1.1 Simulation of reflected solar albedo radiation end ,planetary emitted infrared radiation is generally accomplishedby utillzing judiciously located.infrared heat sources to prevent undesirable blockage of shadow’. 1.2 Procedure II utilizes the confining surface of the chamber to simtilate the cold absorbing nature of space and the radiant heat is provided from an infrared source. 1.3 Procedure III utilizes the confining temperature controlled surfaces of the chamber to force a given calculated temperature on the test object.
1.4 Procedure IV utilizes an infrared source to program heat around the object in zones to simulate orbital skin temperature, 1.S Procedure V utilizes‘a conductive temperature contro1led surface for mounting intez%al components to simulate their heat trsnsfer condition. I..6 procedure VIutilizes a chamber to simulate the pressure effect of 8&e. 1.7 Procedure VII utilizes a cryogenic heat sink plus vehicle heaters. 2. APPARATUS. This section deals with general performance requirements of smne aDDaratus usectin space simulation testing. Performance requirements for a spe;ific test should.be called out in the e@iprnent specification. 2.1 Thermal vacuum chamber:
The test chamber shal1 be capable of providing ( a vacuum of at least 10-- Torr with the test item installed. Vacuum gauges shal1 be calibrated in accordance with ASTM E-297-7O. 2.1.1 Pressure levels recommended for various effects simulation are given in table 517.2-1. I Table.517.2-I.~‘Pressure Level for Effects Simulation Radiant heat transfer Structural 760 to O Torr Below 10-s Torr Dielectric strength Below 10-S Torr Material evaporation To 10-7 Torr Surface effects Below 10-9 Torr S17.2-2 @THOD 517.2.