For critical optical surfaces and sensitive instrumentation, contamination due to spacecraft outgassing is a nuisance. To avoid or minimize the resulting, limiting factors in the future, a comprehensive understanding of the outgassing mechanisms is necessary. Here we summarize findings from outgassing studies using the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) on the Rosetta spacecraft. Data are available for a flight time of more than six years, a large range of heliocentric distances, and a variety of different test scenarios. © 2011 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.