CORROSION IN AEROSPACE ELECTRICAL/ELECTRONIC COMPONENTS IN THE EARLY YEARS OF THE APOLLO PROGRAM, KENNEDY SPACE CENTER,FLORIDA

摘要

CORROSION IN AEROSPACE ELECTRICAL/ELECTRONIC COMPONENTS INTHE EARLY YEARS OF THE APOLLO PROGRAM, KENNEDY SPACE CENTER,FLORIDA.The two failures discussed resulted in delays of LunarLaunches and, in doing so, changed fabrication techniques ofcross country underground splices and of plating ofelectrical contactors. These failures were caused bycorrosion. The first failure was a lead sheathing over asplice in a cross country communication hookup between theLaunch Control Center and the Launch Complex 39A and 39B atKennedy Space Center, Florida. The lead sheathing wasattacked by sulfate reducing bacteria and moisture resultingin crevice corrosion and allowed moisture to intrude intothe communications cable shorting several systems. Newdrying and suspending cable techniques were devised for theunderground cross country line. The second failure was twogold over silver plated contacts. Gold plate is inherentlyporous which allowed the sulfur from the sulfide ladenatmosphere around Kennedy Space Center to get to the silverplate and lift the gold plate off. A change in platingmaterial to a more corrosive resistant plating as an underplating is being used today in most electronic componentstoday.