Development of Precise Orbit Determination Software for Mars Probe and Data Processing for MEX

We develop a set of independent intellectual property rights software named MAGREAS (Mars gravity recovery and analysis software/system) to determine the Mars spacecraft orbit and solve Mars dynamic parameters. We introduce the design idea and basic structure of the software, and the three-way Doppler data of MEX (Mars express) from Chinese VLBI Network as well as the two-way Doppler data from ESA are analyzed. The results show that for the three-way Doppler tracking data, the post-fit RMS is 0.079 mm/s, and the maximum difference between post-fit orbit and precise orbit provided by Royal Observatory of Belgium is less than 100 m; for the two-way tracking data, the post-fit RMS is 0.067 mm/s and the maximum difference is less than 10 m. The results indicate MAGREAS is reliable and accurate. This software can provide reference for processing the orbital tracking data of Mars spacecraft of the upcoming Chinese Mars exploration mission.