THERMAL VACUUM LIFE TEST OF AN HSD SOLAR ARRAY DRIVE (HSD NO. 2) (FIRST 2 YEARS OF OPERATION)

摘要

The second of the solar paddle drive mechanisms manufactured by Eaxker Siddelcy dynamics ltd, under the ESTEC supporting technology proramce, 1S undergoing a thermal vacuus life test at noraial operating speed. An initial Acceptance test was carried out in June 1974 and the life test commenced in August 1974. She mechanism has run for two years, to date with the shaft rotating at one revolution per day. During the test the radiator surrounding the mechanism has been held at a constant temperature of 22°C while the shaft temperature, at the array mounting flange, is changed at six monthly intervals so that it operates at either 10°C or CO° C At the beginning of each 6 monthly cycle, thirty "eclipse "temperature cycles are carried out in which the shaft temperature is reduced from 60°C to -20°C in 90 minutes and returned to 60°C.