Mars express interplanetary navigation from launch to mars orbit insertion: The JPL experience

The Jet Propulsion Laboratory (JPL), California Institute of Technology and the National Aeronautics and Space Administration have played a significant role in supporting the safe arrival of the European Space Agency (ESA) Mars Express (MEX) orbiter to Mars on 25 December 2003. MEX mission is an international collaboration between member nations of the ESA and NASA, where NASA is supporting partner. JPL ' s involvement included providing commanding and tracking service with JPL ' s Deep Space Network (DSN), in addition to navigation assurance. The collaborative navigation effort between European Space Operations Centre (ESOC) and JPL is the first since ESA ' s last deep space mission, Giotto, and began many years before the MEX launch. This paper discusses the navigational experience during the cruise and final approach phase of the mission from JPL ' s perspective. Topics include technical challenges such as orbit determination using non-DSN tracking data and media calibrations, and modelling of spacecraft physical properties for accurate representation of non-gravitational dynamics. Also mentioned in this paper is preparation and usage of DSN Delta Differential One-way Range (Delta DOR) measurements, a key element to the accuracy of the orbit determination.