MOS Marine Observation Satellite Type Orbiter Launch Feb. 19, 1987 Mission End April 17, 1996 Objective Environmental and Coastal Protection Learn more about MOS Keep Exploring Discover More from Earth Science Explore Earth Science Earth Science at Work NASA Earth Science helps Americans respond to challenges and societal needs — such as wildland fires, hurricanes, and water supplies… Earth Science Missions In order to study the Earth as a whole system and understand how it is changing, NASA develops and supports… Earth Science Data Open access to NASA’s archive of Earth science data