In-orbit performance of the Anik C and D solar arrays

Telesat Canada uses a number of analytical tools to monitor the health of the Anik satellites. The available solar array power is a key element in determining the availability of satellite transponders. Since solar cells are degraded by the space environment, monitoring of solar array performance is carried out on a regular basis. This paper describes how Telesat performs this task and presents an assessment of the in-orbit data from five Anik C and D satellites. Actual performance, including degradation which resulted from known major solar flare activities, is compared to initial and more recent analytical predictions made by means of the Telesat Solar Array Performance Analysis Program (SAPAP). Also, the space environment is estimated between 1993 and 1998 for the extended operations of the Anik C and D satellites