Planning Strategy and Supporting Tools for the Science Operations of ESA's Planetary Science Missions

Abstract

The European Space Agency (ESA) is commencing a program of interplanetary space missions requiring a Science Operations Centre (SOC) during their routine operations periods for planning the operations. Of this next generation of ESA missions, the Rosetta cornerstone mission is the most challenging from an operational point of view. It’s target, a comet, is one of the inhabitants of the Solar System with an unpredictable behaviour as it gets more active along its journey to the Sun. The ability to actively respond to characteristics or changes observed at the comet is crucial for the success of a cometary mission. This capability, generally referred to as adaptability, obliges the SOC to perform closed-loop operations planning in which scientific results from previous observations are used as an input for future mission operations. In order to translate the mission science objectives into actual operations the SOC has developed a planning strategy including incorporated planning tools in such a way that they can also support the other planetary mission like SMART-1 (to the moon), Mars Express (to Mars) and Venus Express (to Venus). The SOC uses two software tools to assist in the science operations planning procedure. The Project Test Bed (PTB) is an environment simulator, which has the ability to calculate Flight Dynamic events along with events which are important for the science planning (such as illumination and phase angles). This tool is also equipped with a 2 D and 3 D graphical display allowing the user to get a better feeling for the geometrical conditions. The Experiment Planning System (EPS) is a software tool which facilitates the scheduling of experiment operations for multiple experiments in a timeline and checks for conflicts. It also reads in the events generated by the PTB (for simulations) or by Flight Dynamics (in-flight operations). Once a timeline is conflict free it can be converted to the Payload Operations Requests (POR) format and forwarded to Mission Operations Centre (MOC). There the POR will be validated in a Mission Planning System (MPS), which checks for conflicts with the overall spacecraft operations, before it uploads the actual commands to the spacecraft. In this paper the planning strategy will be explained along with the planning tools using examples from several missions to run through the planning process.