ORBIT SELECTION OF A COMPLEMENTARY DATA RELAY MISSION FOR THE CNES AEROCAPTURE DEMONSTRATOR

摘要

CNES is working on a mission that should be launched in 2007 towards Mars. Its primary objective is to demonstrate some critical concepts of future Mars Sample Return missions. Once this demonstration completed, a continuation of the mission can be envisaged, turning to profit the fact that the orbiter does not have to bear the complete payload of the targeted MSR mission. For this extension, a data relay function seems to be a good mission objective. Moreover, this function is mandatory for Netlander probes that will be carried by the CNES 2007 orbiter because they are not powerful enough to communicate directly with the Earth. In this paper, we will identify the best orbits for a data relay mission taking into account orbital constraints that are dictated by the primary aerocapture mission, but also the constraints that limit communications with Netlanders. In this case, the main constraint is the solar illumination because Netlander probes need to be in daylight to send their data. When the extended mission will be fully decided, this analysis will be useful to optimize the final orbits according to Netlander specific needs. Furthermore, this analysis can be easily applied to other data return links from similar small size surface probes on Mars.