Downloaded from https://www.everyspec.com MIL-STD-81OC 10 March 1975 M@THOD 517.2 SPACE SIMULATION (UNMANNEDTEST) 1. PURPOSE. The tests described herein are intended for the evaluation of s-icle components, spa~e Vehicle subsystem and complete space vehicles including installed equipment. a. The space simulation test is performed to determine whether space vehicles, such as satellites, external instrumentationpackages, spacecraft, and space stations with associated equipment can withstand the deleterious effects of very low pressures, low temperatures, end solar radiation. Ordinarily, this test will require establishingrealistic temperature distribution across and through the test item.
Aerodynamic heating is not usual1y considered a part of this test but may be partiallysimulated, if so specified, by the application of heat. b. The details of a space simulation test depend entirely on the particular environmental condition to be simulated and on the purpose and type of test to be simulated and performed. One’of the most significant environments outer space which must be simulated is that of extremely low pressure.
Effects of this environment are the change in convective and conductiveheat tranefer ;&teristic:” Wile outer space pressureshave been measured as l~w as Torr it IS generally accepted that en operating pressure of 1O- Tori is sufficient to avoid convective and gaseous conductive heat trsnsfer and electrical discharge, even though it does not duplicate space conditions in terms of gas material interaction at the surface of the test vehicle. c. Different procedures can be used to simulate the radiant heat trsnsfer effects of the space environment.
1.1 Procedure I utilizes the confining surfaces of the chamber to simulate the CO1d absorbi~ nature of space and the radiant heat is provided from a simulated solar spectrum input.. Energy co]limsted within a few degrees of the true solar condition irradiates the test object held in position by a : fixed or movable fixture. By a combination of motion or repositioningof the test vehicle end progranmzedcontrol of the solar source, simulated orbital or space conditions are achieved. 517.2-1 METHOD 517.2 10 March 197S