Sub-microradian pointing system design for deep-space optical communications

This paper summarizes NASA/JPL progress on sub-microradian pointing system design. Sub-microradian pointing has been found to be critical for the deep space optical communications from earlier studies. The objective of current effort is to develop the needed technologies and demonstrate a sub-microradian pointing capability under simulated spacecraft vibrations. This is expected to establish the foundation for future deep space optical communication missions. The pointing system, once built, should be able to support optical communications anywhere within solar system for non-orbiting spacecraft. The proposed pointing system is based on high precision inertial sensors and large format focal plane arrays, which can operate under low intensity beacon sources such as stars. This design concept drastically deviates from the conventional design limited for short range, which assumes high signal level and quadrant detectors or small format focal plane arrays. We will present the architecture of the pointing system, pointing error analysis, and the progresses on the laboratory validations.