Biographies of Astronaut and Cosmonaut Candidates




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Personal data

Birthdate:  28.02.1956
Birthplace:  Brussels
Marital status:  married
Children:  one
Selection date:  02.05.1991
Position:  LS / PSP
Status:  Ret. ??.07.1995 (only as astronaut candidate)

Additional information

Bachelor in Engineering Sciences (1976), Engineer in Mechanical Engineering (specialism Dynamics and Systems, with Distinction, 1979), Master of Sciences in Physics (specialism Space Geodesy, with the highest distinction, 1980), Ph.D. in Physics (specialism Astronomy and Astrophysics, with the highest distinction, 1990), Catholic University of Louvain, Louvain-la-Neuve, Belgium.
He worked from 1978 to 1980 as Junior Assistant 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 first as System Engineer, then as Project Manager and Experiment Coordinator on the development of scientific payloads for microgravity research on board of Spacelab, Spacehab, Foton, and ISS missions, including: the Advanced Fluid Physics Module (AFPM), to investigate open fluid columns and liquid interfaces (1985-93), flown on Spacelab D2 on STS-55 (Apr. 1993); Fluid Physics Facility (FluidPac-FPF), to investigate fluid interface dynamics (1993-94), flown on Russian Foton-12 satellite (Sep. 1999); Bubble, Drop, Particle Unit (BDPU), to investigate fluid drops and bubble dynamics (1995-96), flown on Spacelab LMS on STS-78 (June 1996); Advanced Protein Crystallization Facility (APCF) (1996-98), flown on Spacehab on STS-95 (Oct. 1998); Zeolite experiments Zeogrid and Nanoslabs and other experiments (2001-02), flown respectively in Zvezda and US Lab. Destiny on ISS during Belgian Taxi Flight mission (Nov. 2002); OmegaHab/AquaHab to study symbiotic processes between fishes and algae (2006-07), flown on Russian satellite Foton M3 (Sep. 2007); Protein Crystallization Diagnostics Facility (PCDF) (1997-09), flown on Columbus, ISS (Feb. 2009); Solution Crystallization Diagnostics Facility (SCDF), to investigate zeolites, colloids and proteins (2008-12), foreseen for ISS; and Dexterous Manipulation (DEX), to investigate hand coordination and object manipulation (2009-14), flown in Columbus on ISS.
He lead space flight operations from ground as AFPM Team Lead at German Space Operation Center (GSOC), Oberpfaffenhofen, Germany (Apr. 1993); BDPU Team Lead at NASA-MSFC Payload Operation and Control Center (POCC), Huntsville, USA (June 1996); APCF Team Lead at Mission Control Center (MCC), NASA-JSC, Houston (Oct. 1998); Physical Science Coordinator at Taxi-Flight Operation Control Center (TOCC), ESTEC (Nov. 2002); Payload Operations Coordinator at Erasmus Payload Operations Centre (EPOC), ESTEC, for Cervantes Soyuz Taxi-Flight mission (Oct. 2003); Deputy ESA Mission Manager for Foton M3 operations, at EMSR - Korolev TsUP, Moscow (Sep. 2007).
He also developed combustion facilities for first European microgravity combustion experiments (1986-87) and microgravity measurement and isolation systems (1985-94) for ESA parabolic flights between 1986 and 1994. In his position of ESA Parabolic Flight Coordinator, Pletser organized and led 65 ESA campaigns for more than 1000 experiments in physical and life sciences and technology on NASA KC-135/930 (1985-88), CNES Caravelle (1989-95), Roscosmos Ilyushin Il-76 MDK (1994), Dutch NLR Cessna Citation II (2001), CNES-ESA Airbus A300 ZERO-G (1997-2014) and CNES-ESA-DLR Airbus A310 ZERO-G (2015-16). He participated in 25 other campaigns of NASA, CNES, DLR and the Canadian Space Agency. He logged 7389 parabolas, representing 39h 34m of weightlessness, equivalent to 26.3 Earth orbits (more than first NASA astronauts, Russian cosmonauts and Chinese taikonaut) and 53 min. at Mars-g and 50 min. at Moon-g. He was Principal Investigator of 11 micro-accelerometric experiments and of 2 fluid physics experiments. He participated as Scientific Operator in 83 physical and life sciences and technology experiments and as Human Test Subject in 99 medical and physiology experiments. He participated also in gravity-related experiments on ground (11x), in centrifuge (2x) and in water immersion (1x). He holds the official Guinness World Record for the number of airplanes (14) on which he flew parabolas. He served as Flight instructor for public Discovery Parabolic Flights.
From 2016 to 2018, he was invited by the Chinese Academy of Sciences to work as Visiting Professor - Scientific Adviser at the Technology and Engineering Centre for Space Utilization in Beijing, China, supporting the preparation and development of microgravity research instrumentation for parabolic flights and for the Chinese Tiangong Space Station.
Since 2018, he is Director of Space Training Operations at Blue Abyss, a company based in UK, proposing a new approach for astronaut training. He is in charge of the definition and implementation of space-related training activities and facilities for private and government astronauts, including parabolic flights 2.0 and underwater EVA training.
Selected by Belgium as Astronaut Candidate in 1991 for the second ESA selection, he was not retained because of a mistake in the medical assessment, which was recognized later on by ESA.
He was presented by Belgium as Payload Specialist candidate for Spacelab IML-2 (not retained by NASA, 1992), Spacelab MSL (Material Sciences Laboratory, not retained by NASA,1995), Spacelab LMS (Life and Microgravity Spacelab) for which he was recommended by the LMS - Investigator Working Group (IWG), he passed the medical selection at NASA (1995), and he started training during two months together with Favier, Urbani and Thirsk at NASA-JSC, Houston. He was very close to be selected as a payload specialist for STS-78. However, due to political reasons, he was replaced by Duque. He further followed EVA training at the EAC NBF (2010-11)
He was Astronaut Training Instructor for Parabolic Flights with ESA astronauts and for NASA and DLR astronauts for several Spacelab missions.
Selected in 2001 by The Mars Society, a private organization promoting the human exploration of Mars, he participated in three international simulation campaigns of Mars missions in the Arctic Circle in 2001 and in the Desert of Utah in 2002 and as Crew Commander in 2009.
He is visiting Professor in 20 universities in Europe, USA, Canada, Africa, Israel, and China. He has more than 800 publications, including 6 books, 18 book chapters, 70 articles in refereed journals and 154 articles in international conferences proceedings.
He is member of the International Astronautical Academy and of several other academies and scientific organizations. He is recipient of several Awards and Honors, including the Life Sciences Book Award (2023) and the Engineering Sciences Book Award (2017) of the International Academy of Astronautics.
He is an aircraft pilot (PPL) and a confirmed Scuba diver with dives in Arctic, Antarctic, under ice, and deep diving with gas mixes. He played rugby at international level, captaining the Belgium Rugby National Team. He holds a Black Belt 4th Dan of Judo and practiced several other sports, running, swimming, snorkeling, squash, triathlon, motocross, alpine ski, hill walking. His hobbies include traveling, cinema, listening to music, reading, cooking, chess and working on problems of celestial mechanics, astronomy and mathematics.


Last update on January 06, 2023.