Tecstar Inc. and JX Crystals Inc. have been working together to build a prototype module to demonstrate high efficiency achieved by mechanically stacking cells for the BMDO SBIR Phase II project. Recent test reports confirm Tecstar’s space cell technology has successfully reached a 33.4% cell efficiency at 15AMO. The GaInP/GaAs cell made by Tecstar is 27%, and GaSb made by JX Crystal is 6.4%.