1. Space Research Institute of the Russian Academy of Sciences (IKI), 84/32 Profsoyuznaya St., Moscow 117997, Russia
2. European Space Agency, ESTEC, Keplerlaan, 2200 AG Noordwijk, The Netherlands
3. AP, RST, FAME, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands
4. Gonitec BV, J. Bildersstraat 60, 2596 EJ Den Haag, The Netherlands
5. Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
6. Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 12800 Prague 2, Czech Republic