This edited book is complementary to Large Antennas of the Deep Space Network (Wiley 2002), which describes all the ground antennas used in support of the spacecraft. Spaceborne Antennas for Planetary Exploration traces the development of the Jet Propulsion Laboratory (JPL) spacecraft antennas from the first Explorer satellite in 1958 to the present. It deals primarily with the radio frequency (RF) design and performance of the antennas and also includes material on environmental and mechanical considerations. It describes all the new designs and technological innovations introduced throughout their evolution. There is also a thorough treatment of all the analytical and measurement techniques used in the design and performance assessment. The technical terms assume that the reader is familiar with basic engineering and mathematical concepts as well as material typically found in a senior level course in electromagnetics.