The E.S.A. (European Space Agency) organizes the Small Satellites Systems and Services Symposium(4S Symposium), to be held on 26 – 30 May 2008 at Hilton Hotel in Rhodes. The 4S Symposium is a biennial event that was first held in 1992. The symposium has a large international participation. Representatives from 25 nations attended the last event. The symposium is an excellent working environment where technical sessions are complemented by opportunities to exchange ideas and opinions on technologies and utilization of small satellites. The quality of the contributions, mixed with the special atmosphere of the symposium, gives this event a unique taste.