3D Direct Simulation Monte Carlo Modeling of the Spacecraft Environment of Rosetta
Andre Michel Bieler1, Valeriy Tenishev2, Nicolas Fougere1, Tamas I Gombosi1, Kenneth C Hansen1, Michael R Combi1, Zhenguang Huang2, Xianzhe Jia3, Gabor Toth4, Kathrin Altwegg5, Peter Wurz6, Annette Jäckel7, Lena Le Roy5, Sébastien Gasc7, Ursina Calmonte5, Martin Rubin8, Chia-yu Tzou7, Myrtha Hässig9, Stephen A Fuselier10, Johan De Keyser11, Jean-Jacques Berthelier12, Urs A. Mall13, Henri Rème14, Björn Fiethe15 and Hans Balsiger5, (1)University of Michigan, Ann Arbor, MI, United States, (2)University of Michigan, Climate and Space Sciences and Engineering, Ann Arbor, United States, (3)University of Michigan, Department of Climate and Space Sciences and Engineering, Ann Arbor, United States, (4)University of Michigan Ann Arbor, Ann Arbor, United States, (5)University of Bern, Bern, Switzerland, (6)University of Bern, Space Research and Planetary Sciences, Bern, Switzerland, (7)University of Bern, Physikalisches Institut, Bern, Switzerland, (8)University of Bern, Physics Institute, Space Research and Planetary Sciences, Bern, Switzerland, (9)Southwest Research Institute San Antonio, San Antonio, TX, United States, (10)Southwest Research Institute, San Antonio, United States, (11)Belgian Institute for Space Aeronomy, Brussels, Belgium, (12)LATMOS Laboratoire Atmosphères, Milieux, Observations Spatiales, Paris Cedex 05, France, (13)Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, (14)IRAP, Institut de Recherche en Astrophysique et Planétologie, Toulouse, France, (15)Technical University of Braunschweig, Braunschweig, Germany
Abstract:
The European Space Agency’s Rosetta mission is the first to escort a comet over an extended time as the comet makes its way through the inner solar system. The ROSINA instrument suite consisting of a double focusing mass spectrometer, a time of flight mass spectrometer and a pressure sensor, will provide temporally and spatially resolved data on the comet’s volatile inventory.
The effect of spacecraft outgassing is well known and has been measured with the ROSINA instruments onboard Rosetta throughout the cruise phase. The flux of released neutral gas originating from the spacecraft cannot be distinguished from the cometary signal by the mass spectrometers and varies significantly with solar illumination conditions. For accurate interpretation of the instrument data, a good understanding of spacecraft outgassing is necessary. In this talk we present results simulating the spacecraft environment with the Adaptive Mesh Particle Simulator (AMPS) code. AMPS is a direct simulation monte carlo code that includes multiple species in a 3D adaptive mesh to describe a full scale model of the spacecraft environment. We use the triangulated surface model of the spacecraft to implement realistic outgassing rates for different areas on the surface and take shadowing effects in consideration. The resulting particle fluxes are compared to the measurements of the ROSINA experiment and implications for ROSINA measurements and data analysis are discussed. Spacecraft outgassing has implications for future space missions to rarefied atmospheres as it imposes a limit on the detection of various species.
