An overview of the Mars exploration rovers' flight software

The Mars exploration rovers (MER) flight software (FSW) is possibly the most complex software implementation to be deployed on another planet. The requirements dictated a software system that addressed four distinct mission phases (cruise, landing, egress, and surface) and the mission demanded a system with significant autonomy. The structure of the MER flight software reflects its object-oriented beginnings and the overall function reflects the requirements of the MER mission and spacecraft. This paper provides an overview of the function and structure of the MER flight software. The MER mission and spacecraft are briefly discussed to provide context for the flight software decomposition and the discussion of the software execution model.