CABLE AND HARNESS GENERAL REQUIREMENTS - DISCRETE WIRE HARNESSES. Harnesses exhibit a neatly organized layout with smooth bends and sufficient stress relief. Connector cable clamps and cable straps are properly set. NASA-STD-8739.4 [19.6.1.e] PREFERRED. DUST CAPS. The mating surfaces of all unmated connectors shall be protected by covers during storage, handling and installation. NASA-STD-8739.4 | NASA Technical Standards System (NTSS) The purpose of this NASA Technical Standard is to set forth requirements for interconnecting cable and harness assemblies that connect electrical, electronic or electromechanical components. This standard applies to critical work, as defined by NPD 8730.5.