Attila Baksa
On-board autonomy of lander units for comet nucleus exploration
Keeping lander units functional in the hostile, energy-lacking environment in the outskirts of our Solar system is a great challenge. An autonomous real-time control system of a lander is expected to response on board to both nominal and non-nominal events without any external intervention. Recent developments in microelectronics make it possible to use such spacequalified microprocessors that allow the development of highly autonomous on-board software systems. But the increased computing power itself is not all - equally advanced software methods are also needed to provide real autonomy. Considering the complexity of a number of mutually interacting tasks, it is necessary to model them by well-described abstract logical modules. Our focus was on managing the static and dynamic behaviour of the system separately and eventually we developed the Mission Sequencing Object Model Language for describing the long-term autonomous mission control mechanism. This model was implemented on the Philae Lander for the Rosetta mission of the European Space Agency, which was successfully launched on 2 March 2004.