Bonn 2010 – wissenschaftliches Programm

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GR: Fachverband Gravitation und Relativitätstheorie

GR 6: Experimente zur Gravitation 2

GR 6.6: Vortrag

Dienstag, 16. März 2010, 15:40–16:00, JUR K

Modelling and evaluation of Pioneer 10/11 thermal recoil: Work status and first results — •Benny Rievers and Claus Lämmerzahl — Zentrum für angewandte Raumfahrttechnologie und Mikrogravitation (ZARM), Universität Bremen, Am Fallturm, 28359 Bremen

The origin of the anomalous constant deceleration of the Pioneer 10/11 spacecrafts, first identified by Anderson et al in 1998, has been subject of several scientific investigations and speculations. Many systematic effects have been ruled out as the cause, however, the anisotropic radiation emitted by the crafts is supposed to explain at least a non-negligible part of the observed anomaly. In order to evaluate the exact magnitude and the dynamics of thermal recoils a method based on ray tracing and finite element (FE) modeling has been developed at the Center of Applied Space Technology and Microgravity (ZARM). Preliminary results show that a significant amount of the observed effect can be credited to thermal effects. A complete FE model of Pioneer 10 including detailed outer shape, internal payloads and temperature measurements of the radioisotopic thermal generators is developed at ZARM and will enable the exact evaluation of thermal disturbance accelerations. An overview of the current work status and a detailed insight in the used method will be given. Besides the evaluation of thermal effects with respect to Pioneer anomaly investigations the elaborated method can also benefit the upcoming high-precision missions (LISA, LISA pathfinder, MICROSCOPE ...) where the high scientific requirements demand precise modeling of thermal perturbations.