SIM PlanetQuest telescope, computer artwork. SIM (the Space Interferometry Mission) is a space telescope being designed by NASA and managed at the Jet Propulsion Laboratory (JPL) in California, USA. It will use optical interferometry, where two or more light waves are superposed in order to detect differences between them, to accomplish several scientific goals. These include hunting for extrasolar planets (planets in orbit around distant stars), mapping the Milky Way Galaxy and determining the spatial distribution of dark matter in the universe. The preliminary launch date is set for 2015.