Essential Research Inc. of Cleveland is working on a high-efficiency, radiation-resistant solar cell to provide satellite power. The company plans to grow durable, inexpensive, high-quality indium phosphide solar cells on germanium substrates. The radiation tolerances of such cells should decrease the photovoltaic array size necessary to power satellites, resulting in lower launch costs and larger payloads. The company's aim is to grow solar cells with conversion efficiencies better than 16 percent. The work is sponsored by a two-year, $600,000 Small Business Innovation Research Phase II grant from NASA.