Injection of a Body into a Geodesic: Lessons Learnt from the LISA Pathfinder Case

Launch lock and release mechanisms constitute a common space business, however, some science missions due to very challenging functional and performance requirements need the development and testing of dedicated systems. In the LISA Pathfinder mission, a gold-coated 2-kg test mass must be injected into a nearly pure geodesic trajectory with a minimal residual velocity with respect to the spacecraft. This task is performed by the Grabbing Positioning and Release Mechanism, which has been tested on-ground to provide the required qualification. In this paper, we describe the test method that analyzes the main contributions to the mechanism performance and focuses on the critical parameters affecting the residual test mass velocity at the injection into the geodesic trajectory. The test results are also presented and discussed. d University of Trento, Trento, Italy a European Space Astronomy Centre, European Space Agency, Madrid, Spain b Albert-Einstein-Institut, Hannover, Germany c Universite Paris Diderot, Paris, France e Airbus Defence and Space, Immenstaad, Germany f European Space Technology Centre, European Space Agency, Noordwijk, The Netherlands g Dipartimento di Fisica, Universita di Trento, Trento, Italy h Department of Physics and Astronomy, University of Birmingham, Birmingham, UK i Airbus Defence and Space, Stevenage, UK j Institut fur Geophysik, Zurich, Switzerland k Institut de Ciencies de l'Espai, Bellaterra, Spain l Istituto di Fisica, Universit_a degli Studi di Urbino, Urbino, Italy m European Space Operations Centre, Darmstadt, Germany n The Blackett Laboratory, Imperial College London, UK o Physik Institut, Universitat Zurich, Zurich, Switzerland p SUPA, Institute for Gravitational Research, University of Glasgow, Glasgow, UK q Department d'Enginyeria Electronica, Universitat Politecnica de Catalunya, Barcelona, Spain r Institut d'Estudis Espacials de Catalunya, Barcelona, Spain s NASA Goddard Space Flight Center, Greenbelt, MD t CGS S.p.A, Compagnia Generale per lo Spazio, Milano, Italy u Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL v RUAG Space, Zurich, Switzerland Proceedings of the 43rd Aerospace Mechanisms Symposium, NASA Ames Research Center, May 4-6, 2016 https://ntrs.nasa.gov/search.jsp?R=20160008114 2019-06-26T20:35:28+00:00Z