ATS-5 solar cell experiment after 699 days in synchronous orbit.

The data from the ATS-5 solar cell experiment for the first 699 days in synchronous orbit is presented. Comparison of the performance of several different types of solar cell/coverslide configurations is made. This behavior is in turn compared with the calculated performance for such cell/coverslide configurations in synchronous orbit and with the results of accelerator irradiations designed to simulate the omnidirectional electron environment. It is generally found that the cells on the flight experiment perform like the cells irradiated with the accelerator, but they degraded more than predicted by the calculation. Solar cells mounted on a thin kapton panel are degrading about the same as are their counterparts mounted on a rigid panel.