The SWARM mission
Expected to be launched in 2009, SWARM is a spacecraft mission dedicated to the fine evaluation the Earth’s magnetic field and its fluctuations. The SWARM mission consists of several spacecraft flying in formation along a LEO orbit with an altitude about 300/530 km.
The expected platform design is close to that of CHAMP. Several instruments of the scientific payload, like the Canadian Electric Field Instrument (CEFI), may potentially be sensitive to the electrostatic charge of the spacecraft and the modifications of its electrostatic sheath and ionic wake structure. CEFI will determine electric field through precision measurements of ion drift velocity, derived from a novel electrostatic analyzer, which can potentially be perturbed by the electrostatic sheath or the wake structure of the spacecraft. CEFI also incorporates two Langmuir Probe sensors and electronics provided by the Swedish Institute for Space Physics, Uppsala, which may also potentially be perturbed by the modification of the surrounding electrostatic environment.
The SPIS system is an open-source software dedicated to the fine simulation the
spacecraft plasma interactions. SPIS is able to model realistic 3D spacecraft models and detailed mechanisms including spacecraft charging, surface interaction/secondary emission, sheath structure in a wide range of plasma conditions (LEO, MEO, GEO). Initiated by ESA, SPIS is today maintained in the frame of the SPINE community.
Objectives of the study
The global aim of the study is a first characterisation of the electrostatic charge of SWARM and a first evaluation of its potential impact on the measurement of CEFI.
The detailed technical goals of the study are:
- Develop a set of 3D electrostatic models of SWARM and CHAMP compliant with SPIS 3.6, including:
- A complete geometrical model (CAD) compliant with the GEOM module of SPIS;
- Definition of local properties (IBC) corresponding to information provided in the spacecraft design;
- Definition of global parameters corresponding to the most frequent flight conditions.
- Definition of a simplified internal electric circuit, taking into account the actual grounding configuration of the solar arrays;
- Perform a numerical computation of the floating potential of the spacecraft;
- Perform a numerical computation of the electric field and plasma density in front of the CEFI sensors
Collaborative tools
- Swarm Internal Exchange Area Please find here various documents relative to the Champ/Swarm S/C-charging study. VRML 3D models can be viewed directly into a Web browser using a VRML/WRL plug-in. Free plug-ins are availables here.
