JPL DESCANSO - Deep Space Communications and Navigation Center of Excellence

The GRACE Mission: Architecture of the Flight Segment

Presented by:
Edgar S. (Ab) Davis
GRACE Mission Project Manager


The Gravity Recovery and Climate Experiment (GRACE) Mission launched in March 2002. Within the first year of the GRACE Mission, the Project has a minimum science requirement to deliver a new model of the Earth's static geoid with an error of less than 1 cm to spherical harmonic degree seventy (70). However, the performance of the GRACE Mission is designed to exceed this minimum requirement by a factor of 25 or more. For spherical harmonic degrees of up to 40, we expect to improve the current knowledge of the gravity field by one thousand (1000x). We now have two satellites on orbit that are capable of performing at a level that has never been approached before for a cost of less than 79 million dollars. This talk will address the role of focus, balance, and risk containment in developing the architecture of the flight segment of the mission. The path taken will be set in the context of paths not taken in synthesizing design of the flight segment.

The Speaker

Edgar S. (Ab) Davis received his B.S. in Mechanical Engineering in 1960 and his M.S. in Electrical Engineering in 1961 from Carnegie Mellon University. He joined the Jet Propulsion Laboratory in 1961 and developed the Canopus sensors for JPLís early planetary missions. At Caltechís Environmental Quality Lab in the early 1970ís, he initiated a program for JPL in terrestrial applications solar energy. In 1985 he accepted responsibility for the GPS POD Experiment which subsequently demonstrated cm-level orbit determination on TOPEX/POSEIDON. He led the effort to secure the GRACE Mission for JPL and UT-CSR and is the Project Manager.

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