ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Copernicus Publications Göttingen, Germany 10.5194/angeo-19-655-2001 Disturbance of plasma environment in the vicinity of the Astrid-2 microsatellite Ivchenko N. 1 Facciolo L. 2 1 Lindqvist P. A. 1 Kekkonen P. 3 Holback B. 4 Alfvén Laboratory, Royal Institute of Technology, Stockholm, Sweden Politecnico di Torino, C. so Duca degli Abruzzi, Torino, Italy Oulu University, Oulu, Finland Swedish Institute of Space Physics, Uppsala, Sweden 30 06 2001 19 6 655 666 Copyright: © 2001 N. Ivchenko et al. 2001 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://angeo.copernicus.org/articles/19/655/2001/angeo-19-655-2001.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/19/655/2001/angeo-19-655-2001.pdf

The presence of a satellite disturbs the ambient plasma. The charging of the spacecraft creates a sheath around it, and the motion of the satellite creates a wake disturbance. This modification of the plasma environment introduces difficulties in measuring electric fields and plasma densities using the probe technique. We present a study of the structure of the sheath and wake around the Astrid-2 microsatellite, as observed by the probes of the EMMA and LINDA instruments. Measurements with biased LINDA probes, as well as current sweeps on the EMMA probes, show a density enhancement upstream of the satellite and a plasma depletion behind the satellite. The electric field probes detect disturbances in the plasma potential on magnetic field lines connected to the satellite.<br><br><b>Key words. </b>Space plasma physics (spacecraft sheaths, wakes, charging; instruments and techniques)