Federico Ronci, University of Rome Tor Vergata, Italy; Corrado Avolio, Mauro Di Donna, Massimo Zavagli, e-GEOS - an Italian Space Agency and Telespazio company, Italy; Veronica Piccialli, University of Rome Tor Vergata, Italy; Mario Costantini, e-GEOS - an Italian Space Agency and Telespazio company, Italy