NASA's Crustal Dynamics Project (CDP) spearheaded a major scientific and engineering effort over the last decade to develop and apply space geodetic techniques such as Very Long Baseline Interferometry (VLBI) and Satellite Laser Ranging (SLR) to a wide range of problems in the Earth sciences. Major study areas included plate motion, broad scale crustal deformation, polar motion, and variation in the Earth's rotation rate. Observations were initiated all over the world in collaboration with international scientists and agencies, while university and other scientists in this country received funding for research projects utilizing the new data. Numerous accomplishments over the lifetime of the CDP (to be summarized in an upcoming AGU monograph) include an order of magnitude improvement in the accuracy of space geodetic measurements; monitoring variations in the Earth's pole position and rotation rate with astounding resolution, leading to greatly improved understanding of the underlying physics; and demonstration of a remarkable consistency in plate velocities from geodetic (decadal) to geologic (several-million-year) time scales.