O'Neill founded Geostar Corporation to develop a satellite position determination system for which he was granted a patent in 1982. The system, primarily intended to track aircraft, was called Radio Determination Satellite Service (RDSS). In April 1983 Geostar applied to the FCC for a license to broadcast from three satellites, which would cover the entire United States. Geostar launched GSTAR-2 into geosynchronous orbit in 1986. Its transmitter package permanently failed two months later, so Geostar began tests of RDSS by transmitting from other satellites. With his health failing, O'Neill became less involved with the company at the same time it started to run into trouble. In February 1991 Geostar filed for bankruptcy and its licenses were sold to Motorola for the Iridium satellite constellation project. Although the system was eventually replaced by GPS, O'Neill made significant advances in the field of position determination.