The Evolution of Rosetta-Philae Science Planning Processes Following the Philae Landing

Abstract

The International Rosetta mission is a European Space Agency (ESA) mission with contributions from its member states and the National Aeronautics and Space Administration (NASA). It is the third and final cornerstone mission (after XMM and Cluster/SOHO) of the ESA Horizon 2000 programme and was launched on 2nd March 2004. The mission, which consists of the Rosetta orbiter and the Philae lander, is the first to rendezvous with, orbit, and deploy a lander onto, a cometary body. These unique activities intend to address the scientific goal of mapping the comet 67-P/Churyumov-Gerasimenko by remote sensing, to examine its environment in-situ and its evolution in the inner solar system. The spacecraft arrived at the comet in summer 2014 and in November 2014, Philae was deployed onto the comet´s surface. In August 2015 comet 67-P reached perihelion and Rosetta will continue to study 67-P before finally landing on its surface in September 2016.The Rosetta science operations are coordinated by the Rosetta Science Ground Segment (RSGS), located at ESA´s European Space Astronomy Centre (ESAC) in Madrid, Spain. The RSGS constructs, in coordination with the Principle Investigator science teams and ESA's Rosetta Mission Operations Centre (RMOC), a plan of scientific observations and provides conflict free operational products for uplink and execution on-board. In parallel, the dedicated Lander Ground Segment (LGS), builds a similar plan and operational products, for Philae platform and scientific experiment activities according to the Philae scientific community´s science objectives. The RSGS must therefore interact closely with the LGS throughout the planning process in order to ensure that all Rosetta and Philae science activities are correctly coordinated and mutually compati ble.The successful but non-nominal Philae landing, combined with the overall evolution of the RSGS' own planning processes in response to the dynamic cometary environment and Rosetta spacecraft constraints, demanded an evolution of these RSGS-LGS interactions that had originally been established prior to the landing event. In this paper, we will detail the major impacting operational issues in this context, and how the RSGS adapted and enhanced the original concept and the internal planning tools & processes in use, in order to maintain the required ability to continually integrate compatible Rosetta and Philae science operations plans throughout the post-landing comet escort phase. We will also detail how this evolution was then put into practise following the June 2015 Philae wake-up, and what further planning challenges this then also presented to the RSGS, and its overall goal of optimizing the mission´s scientific return. Nomenclature