IMPALAS: Investigation of MagnetoPause Activity using Longitudinally-Aligned Satellites—a mission concept proposed for the ESA M3 2020/2022 launch

Owen, C.J. and Amm, O. and Bruno, R. and De Keyser, J. and Dunlop, M.W. and Eastwood, J.P. and Fazakerley, A.N. and Fontaine, D. and Forsyth, C. and Hasegawa, H. and Hellinger, P. and Hercik, D. and Jacquey, C. and Milan, S. and Raeder, J. and Sibeck, D.G. and Stverak, S. and Travnicek, P. and Walsh, A.P. and Wild, James (2012) IMPALAS: Investigation of MagnetoPause Activity using Longitudinally-Aligned Satellites—a mission concept proposed for the ESA M3 2020/2022 launch. Experimental Astronomy, 33. pp. 365-401. ISSN 0922-6435

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The dayside magnetopause is the primary site of energy transfer from the solar wind into the magnetosphere, and modulates the activity observed within the magnetosphere itself. Specific plasma processes operating on the magnetopause include magnetic reconnection, generation of boundary waves, propagation of pressure-pulse induced deformations of the boundary, formation of boundary layers and generation of Alfvén waves and field-aligned current systems connecting the boundary to the inner magnetosphere and ionosphere. However, many of the details of these processes are not fully understood. For example, magnetic reconnection occurs sporadically, producing flux transfer events, but how and where these arise, and their importance to the global dynamics of the magnetospheric system remain unresolved. Many of these phenomena involve propagation across the magnetopause surface. Measurements at widely-spaced (Δ ˜ 5 RE) intervals along the direction of dayside terrestrial field lines at the magnetopause would be decisive in resolving these issues. We describe a mission carrying a fields and plasmas payload (including magnetometer, ion and electron spectrometer and energetic particle telescopes) on three identical spacecraft in synchronized orbits. These provide the needed separations, with each spacecraft skimming the dayside magnetopause and continuously sampling this boundary for many hours. The orbits are phased such that (i) all three spacecraft maintain common longitude and thus sample along the same magnetopause field line; (ii) the three spacecraft reach local midday when northern European ground-based facilities also lie near local midday, enabling simultaneous sampling of magnetopause field lines and their footprints.

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Journal Article
Journal or Publication Title:
Experimental Astronomy
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07 Jun 2012 15:42
Last Modified:
20 Sep 2023 00:21