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).

The Deep Space Network (DSN), managed by the Jet Propulsion Laboratory for NASA, is equipped with multiple microwave transmitters ranging in average radiated power from 200 W to 400 kW. The transmitters are used for routine or emergency communication with spacecraft, for navigation, and for radio science tasks. The latest advances in transmitter engineering were implemented in a new generation of 20-kW dual-band transmitters developed for the DSN 34-m beam waveguide antennas. Innovations include additional X-band communication capability for near Earth missions, new c, automated calibration, improved and expanded computerized monitoring and diagnostics, reduced cabling, and improved maintainability. The innovations were very beneficial for the DSN ldquooverloadrdquo during the Mars 2003/2004 missions and will benefit other missions throughout the next decade. This paper describes the current design of the new transmitters and possible future developments.