Solar cells that provide as much as 50% more power for Earth-orbiting satellites will help flash back telephone and television signals from space. The cells are based on the two-junction, gallium indium phosphide on gallium arsenide designs developed at the Department of Energy's National Renewable Energy Laboratory (NREL) (Golden, CO). TECSTAR Inc. (City of Industry, CA) licensed two patents covering the technology for space use. It has adapted the NREL technology to use germanium substrates for the epitaxial growth of the cells. This, in turn, should result in greater efficiencies and reduced costs for space missions. Commonly used silicon cells lose about half of their efficiency after five years in space. The gallium indium phosphide top layers of the new NREL cells have far more resistance to radiation damage, giving them a much longer space life. E-mail email@example.com.