Dušan Petrač
(1932–)
NASA collaborator on the construction of the first infrared astronomical satellite (IRAS)
Dušan Petrač was born in Kropa in the Gorenjska region in 1932. He graduated in physics from the University of Ljubljana. He continued his studies at the postgraduate level at the Faculty of Physics and Astronomy of the University of California, Los Angeles (UCLA) with a doctorate in physics.
He conducted research work at the Jet Propulsion Laboratory (JPL) at the California Institute of Technology, Pasadena, California, in NASA research projects. At JPL, he participated in developing and implementing four scientific and technological experiments in microgravity on space taxis, and in two further experiments, he also collaborated with Stanford University. His most demanding tasks were designing and constructing the first infrared astronomical satellite (IRAS) in cooperation with the Netherlands and Great Britain. The IRAS was associated with many epochal discoveries or inventions distinguished. Dr. Petrač contributed to controlling the infrared focal “plane” with 64 detectors in four infrared wavebands. He introduced a method for measuring the mass of superfluid helium in weightlessness. This method was also used at the European Infrared Observatory, on the Spitzer Space Telescope.
His contribution to the use of semiconductor electronics at low temperatures is also significant. He also developed a He-3 and He-4 dilution cooler that would work in weightlessness. He was involved in developing detectors for the “Terrestrial Planet Finder” mission, aiming to detect Earth-like planets around “nearby” stars, using optical interference methods.
He was a consultant to Stanford University, the Freie Universität in Berlin, the University of Tsukuba, and Lockheed Martin Marietta.
For his services in introducing cryogenics into space, he received the Dr. Kurt Mendelssohn medal, recognition at the International Cryogenic Engineering Conference. He also received the NASA Medal of Outstanding Merit and was awarded the title of Honorary Senator of the University of Maribor. Dr. Petrač is an honorary citizen of Los Angeles.