This Standard describes the methodology, instruments, equipment and samples, used to calculate the thermo-optical properties of thermal-control materials. The following test methods are detailed in this Standard including the configuration of samples and calculations: - Solar absorptance using spectrometer (?s) - (see Annex C.2). - Comparative test method (?p) - (see Annex C.3). - Infrared emittance using thermal test method (?h) - (see Annex C.4). - Infrared emittance using IR spectrometer (?h) - (see annex C.5). - Infrared emittance using portable equipment (?n) - (see Annex C.6). This standard may be tailored for the specific characteristics and constraints of a space project in conformance with ECSS-S-ST-00.