Oliver Küchemann

The Central on-Board Computer of the Philae Lander in the Context of the Rosetta Space Mission

The Rosetta-Philae space mission is an unprecedented venture. After a ten-year journey across the Solar System and many complicated manoeuvres, the Rosetta spacecraft smoothly approached a small (2-4 km in diameter) celestial body, comet CG/67P. Furthermore, the spacecraft executed additional fine manoeuvres to fly a multitude of low and high altitude orbits around the comet, mapping its shape and surface in detail never seen before, and has continued to observe it for a year since then. The Rosetta spacecraft is equipped with scientific instruments that deliver a wealth of new knowledge about the CG/67P comet, in addition to spectacular pictures. Delivering the Philae lander onto the surface of the comet 500 million km away from Earth was also a remarkable technological success. The direct measurements made by the Philae lander on the surface of the comet provided significant new knowledge. The first half of this paper gives a brief overview of the objectives and highlights of the Rosetta-Philae mission. In the second half the major hardware and software design aspects, including the conceptual design and implementation of the central on-board computer (CDMS) of the Philae lander are outlined. It focuses on the implementation of fault tolerance, autonomous operation and operational flexibility by means of specific linked data structures and code execution mechanisms that can be interpreted as a kind of object oriented model for mission sequencing.

HP3 – Experiment on InSight Mission – Operations on Mars

HP – the Heat Flow and Physical Properties Package – is an experiment package on-board the upcoming NASA Mars Mission InSight (Interior Exploration Using Seismic Investigation, Geodesy, and Heat Transport).The InSight Mission will investigate the interior structure of Mars using seismoligical and geodetical measurements and quantify the planetary heat budget by measuring the surface planetary heat flow. InSight is scheduled to be launched in May 2018 and to land on Mars at end of November 2018. The main payloads of the InSight lander are a seismometer (SEIS), the HP heat flow probe, as well as the Rotation and Interior Structure Experiment (RISE). An ancillary sensor package consisting of atmospheric pressure and temperature sensors (APSS) as well as a magnetometer complement the payload. After landing on Mars the seismometer and HP will be deployed onto the Martian surface by the robotic arm of the lander. HP is the contribution of DLR (Deutsches zentrum für Luft und Raumfahrt, Germany) to the InSight mission. It is designed to determine the geothermal heat flux by penetrating down into the Martian surface to at least 3m, with the goal of reaching 5m depth. HP measures the thermal conductivity as function of depth during the penetration phase, and the thermal profile of the subsurface will be monitored for a full Martian year after reaching the final depth.