I am a Senior Research Scientist with the UT Center for Space Research. I completed the Ph.D. program in Orbital Mechanics at UT-ASE/EM in 1993, and have stayed here ever since. My primary research activities are in analysis of the space geodetic data for the determination of the Earth's shape, orientation and its gravity field - primarily from precision orbit determination using terrestrial and space-based satellite tracking data. In the mid-90s, I became part of the team that proposed and formulated the joint NASA/DLR GRACE mission, which has provided unprecedented new insights into the mass flux variability, driven by diverse processes within the Earth system. In 2007, we attempted to adapt this concept to study the structure and variability of Mars climate, in the MarsGRACE mission concept proposed to the Mars Scout program. I intend to continue exploring the application of geodetic methods to planetary geodynamics and geophysics.