Johannes Alphonsus Marie "Johan" Bleeker (born 20 July 1942) is a Dutch space research and technology scientist. He was director of the Netherlands Institute for Space Research from 1983 to 2003. He was involved in the setting up of the Horizon 2000 and Horizon 2000+ long term space science programs of the European Space Agency.
Bleeker stayed at Leiden University and worked at the Cosmic-Ray Working Group until 1983, during the final two years he was group leader. In 1983 he became director of the Utrecht Laboratory for Space Research, which later became the Netherlands Institute for Space Research. Bleeker was director until 2003, he was succeeded by Karel Wakker [nl].[3]
Apart from his position at the Netherlands Institute for Space Research Bleeker was a professor of space research and exploration at Utrecht University. He was an extraordinary professor (Dutch: buitengewoon hoogleraar [nl]) from 1985 to 1991, and was then appointed as full professor. He took up emeritus status in 2007.[1]
Bleeker chaired the Survey Committee that set up the long term space science program Horizon 2000 of the European Space Agency and also took part in establishing the follow-on program Horizon 2000+.[2][4] In 1996 he publicly criticized the budget constraints on these programs, which were imposed by the European ministers.[5]