ASTROMETRIC DETECTION OF EARTH-LIKE PLANETS WITH OSI

The Orbiting Stellar Interferometer (OSI) is a space-based astrometric interferometer designed primarily for wide-angle astrometry. OSI is p otentially capable of achieving astrometric accuracies of similar to 1 mu as in narrow angle (1 degrees) astrometry. This paper discusses th e implications for astrometric planet detection, specifically the dete ction of Earth-like planets around nearby stars. OSI has the potential to detect a limited number of planetary systems with Earths, if a num ber of technical problems are solved.