Final results of the Advanced Photovoltaic Experiment flight test

The Advanced Photovoltaic Experiment was designed to generate laboratory reference standards as well as to explore the durability of a wide variety of space power solar cells. In addition to the cells, it was equipped with an absolute cavity radiometer to measure solar intensity, a spectroradiometer to measure the spectral content of this radiation and a Sun angle sensor. Data from the solar cells and various sensors was obtained on a daily basis during the first eleven months of the 69 month flight. In this paper, the authors compare pre-flight and post-flight laboratory measurements with on-orbit calibration data. Pre-flight and post-flight calibration data of the cavity radiometer as well as on-orbit data demonstrated the accuracy and durability of the Eppley instrument flown on APEX.