Solar cells, cell-interconnect-coverglass (CIC) assemblies, solar panels, and solar arrays, which are ‘space-qualified’, having a minimum average efficiency exceeding 20 % at an operating temperature of 301 K (28 °C) under simulated ‘AM0’ illumination with an irradiance of 1 367 watts per square metre (W/m 2 ); Technical note : ‘AM0’, or ‘Air Mass Zero’, refers to the spectral irradiance of sunlight in the Earth's outer atmosphere when the distance between the Earth and the sun is one astronomical unit (AU).