Bachelor in Engineering Sciences, Engineer in Mechanical Engineering (specialism Dynamics and Systems, with Distinction), Master of Sciences in Physics (specialism Space Geodesy, with the Highest Distinction), Doctor of Sciences (Ph.D.) in Physics (specialism Astronomy and Astrophysics, with the Highest Distinction), Catholic University of Louvain, Louvain-la-Neuve, Belgium, respectively in September 1976, June 1979, June 1980 and June 1990; he worked as an Assistant from 1978 to 1980 at the Faculty of Applied Sciences, Catholic University of Louvain, Belgium, for the courses of Regulation and Automatism and Ship Inertial Navigation; after graduating as Mechanical Engineer and Master of Sciences in Physics, he worked as a Research Engineer from 1980 to 1981 at the External Geophysics Department of the Royal Meteorological Institute, Brussels, Belgium, on the Doppler ionospheric effect, and from 1981 to 1982, at the Faculty of Agronomy, Catholic University of Louvain, on problems of applied statistics, mathematical modelization and simulation; in 1982, he was nominated Assistant Professor at the Physics Department of the Faculty of Sciences, Catholic University of Louvain, and detached at the University of Kinshasa, Congo (ex-Zaire), where he lectured until 1985 in Physics, Applied Mathematics, Astronomy and Geophysics, coordinating also physics laboratory activities; in 1985 he joined the European Space Technology and Research Center of the European Space Agency (ESA) in Noordwijk; from 1985 to 1991, he worked as System Engineer on the development of the Advanced Fluid Physics Module (AFPM), an instrument to study the fundamental properties of fluids in microgravity; in 1987, he served as Technical Expert in the ESA Peer evaluation group for the selection of AFPM fluid physics experiments for the Spacelab D2 mission; in 1991, he was nominated Head of the AFPM project and he coordinated the ESA Technical Task Force for AFPM upgrading and tests at ESTEC; he was in charge in 1992 of the final Spacelab integration and checkout activities at the NASA Kennedy Space Center (KSC); during the Spacelab D2 mission on STS-55 in April 1993, he served as AFPM Team Lead for ground operations at the German Space Operation Centre (GSOC), Oberpfaffenhofen, Germany; since 1997 he is the ESA Project Manager for a new protein crystallisation instrument to be flown on the International Space Station; in December 2001, he was nominated ESA Technical Coordinator for two facilities devoted to Zeolite investigations, Nanoslab and Zeogrid, to fly on the ISS during the Belgian Soyuz Taxi-Flight Odissea mission of October 2002; in his position of ESA Parabolic Flights Coordinator, Pletser organized 34 campaigns for physical and life sciences and technology experiments and was the ESA Campaign Director for 33 campaigns; ESA candidate for several IML and Spacelab missions; was very close to be selected as a payload specialist for STS-78, he started training together with Favier, Urbani and Thirsk; due to political reasons he was replaced by Duque; hobbies: practices several sports: jogging, swimming, snorkeling, squash, triathlon, scuba diving, octopush, alpine ski, monoski, judo, traveling, hill walking, cinema, listening to music, reading, cooking and working on problems of celestial mechanics, astronomy and mathematics.