Goldstone Solar System Radar Observatory: Earth-Based Planetary Mission Support and Unique Science Results

The Goldstone Solar System Radar (GSSR) facility is the only fully steerable radar in the world for high-resolution ranging and imaging of planetary and small-body targets. These observations provide information on surface characteristics, orbits, rotations, and polar ices for a wide variety of solar system objects. The resulting data are used not just for scientific studies of these objects, but also for frequent support of the National Aeronautics and Space Administration (NASA) flight projects, including many solar system exploration missions over the last three decades. For example, the GSSR has contributed to the Mars Exploration Rovers (MERs), Cassini, Hayabusa (MUSES-C), MESSENGER, NEAR, SOHO recovery, Mars Pathfinder, Lunar Prospector, Clementine, Magellan, and Viking. Other recent examples include measurement of lunar topography at high resolution near the lunar south pole, which is of particular interest concerning the impact site of the Lunar Crater Observation and Sensing Satellite (LCROSS) mission, and the characterization and orbit refinement of near-Earth asteroids, both for asteroid impact hazard mitigation and for identification of potential targets for future spacecraft missions. We also present important radar scientific results including near-Earth object (NEO) radar imaging of especially interesting objects, and the results from high accuracy determination of Mercury rotation via radar speckle displacement (RSD).