At JPL he worked on the Mariner 9 project as part of the Celestial Mechanics Team .
At JPL he contributed to the gravity field estimation of Mars and overall navigation efforts of the first spacecraft to ever orbit another planet .
At JPL he worked on the Mariner 9 project as part of the Celestial Mechanics Team and contributed to the gravity field estimation of Mars and overall navigation efforts of the first spacecraft to ever orbit another planet .