An Innovative Product for Space Mission Planning

This paper describes MEXAR2, a software tool that is currently used to synthesize the operational commands for data downlink from the on-board memory of an interplanetary space mission spacecraft to the ground stations. The tool has been in daily use by the Mission Planning Team of MARS EXPRESS at the European Space Agency since early 2005. Goal of this paper is to present a quick overview of how the planning and scheduling problem has been addressed, a complete application customized and put into context in the application environment. Then it concentrates on describing more in detail how a core solver has been enriched to create a tool that easily allows users to generate diversified plans for the same problem by handling a set of control parameters, called heuristic modifiers, that insert heuristic bias on the generated solutions. A set of experiments is presented that describes how such modifiers affect the solving process.