DETERMINATION DEGRADATION OF SATELLITE SURFACE OPTICAL FEATURES BY PHOTOMETRIC METHOD

A method is described for using photometric data to estimate the reflective properties of a satellite's surface material under conditions of its long stay in space. The technique of multicolour photometric B,V,R observations of several geostationary satellites built on different types of tires is shown, and the results obtained over a period of 3 to 9 years. These are geostationary satellites Astra 2E (on the Eurostar E3000 bus), Azerspace 2/Intelsat 38 (on the SSL-1300 bus), Sicral 2 (on the Spacebus-4000B2 platform) and Blagovest 11L (the Ekspress-2000 bus). It has been revealed that a pattern of change in the reflectivity of different geostationary satellites is dissimilar. Spacecraft materials used for the surfaces of geostationary satellites manufactured in the second decade of the 21 st century are more resistant to the harsh space environment than those used for the satellites built in the late 20 th century. We have proposed several ways of improving the method for identifying the spacecraft material type based on multicolour photometric observations. The presented results show that the proposed photometric method works and can be used for detecting spacecraft surface degradation.