APEX (Advanced Photovoltaic & Electronic Experiment) successfully tested a wide array of advanced photovoltaic and electronic components in a harsh radiation environment, provided significant data to support improved designs for future space systems. During operation, APEX's highly elliptical orbit allowed the investigation of space plasma effects on high-voltage operation (current leakage at positive voltages and arcing at negative voltages) in the perigee region, plus the investigation of space radiation effects (decreased array power output from passage through the inner radiation belt) in the apogee region.
Elliptical OrbitThe APSTAR 1 spacecraft carries such general communications traffic as voice, fax, data, and television signals across China and Hong Kong, Indonesia, Japan, Singapore, and Vietnam. APSTAR 1A has expanded coverage to India and Pakistan. Hughes Space and Communications International, Inc., signed a contract in May 1992 with APT Satellite Company, Ltd., of Hong Kong for the first satellite. APT ordered APSTAR IA in March 1995. The spacecraft were built at the Hughes Space and Communications Company facilities in El Segundo, Calif.
Geostationary Orbit