An ultraviolet spectrograph (UVS) designed and built by Southwest Research Institute (SwRI) is the first scientific instrument to be delivered for integration onto the European Space Agency’s (ESA) Jupiter Icy Moon Explorer (JUICE) spacecraft. Scheduled to launch in 2022 and arrive at Jupiter in 2030, JUICE will spend at least three years making detailed observations in the Jovian system. Aboard JUICE, UVS will get close-up views of the Jovian moons Europa, Ganymede, and Callisto, all thought to host liquid water beneath their icy surfaces. UVS will record ultraviolet light emitted, transmitted, and reflected by these bodies, revealing the composition of their surfaces and tenuous atmospheres and how they interact with Jupiter and its giant magnetosphere. Southwest Research Institute’s Norm Pelletier prepares the ultraviolet spectrograph (UVS) for delivery and integration onto the European Space Agency’s JUICE spacecraft. As part of a 10-instrument payload to study Jupiter and its large moons, UVS will measure ultraviolet spectra that scientists will use to study the composition and structure of the atmospheres of these bodies and how they interact with Jupiter’s massive magnetosphere. Courtesy of Southwest Research Institute. SwRI has provided ultraviolet spectrographs for other spacecraft, including NASA’s New Horizons spacecraft to Pluto and the Kuiper Belt and the Juno spacecraft now orbiting Jupiter. Another UVS is under construction for NASA’s Europa Clipper mission, scheduled to launch not long after JUICE. “JUICE-UVS is the fifth in this series of SwRI-built ultraviolet spectrographs, and it benefits greatly from the design experience gained by our team from the Juno-UVS instrument, which is currently operating in Jupiter’s harsh radiation environment,” said Steven Persyn, project manager for JUICE-UVS and an assistant director in SwRI’s Space Science and Engineering Division. SwRI’s UVS instrument team comprises scientists from the University of Colorado Boulder, the SETI Institute, the University of Leicester, Imperial College London, the University of Liège, and the Laboratoire Atmosphères, Milieux, Observations Spatiales. The Planetary Missions Program Office at NASA’s Marshall Space Flight Center oversees the UVS contribution to ESA through the agency’s Solar System Exploration Program. The JUICE spacecraft is being developed by Airbus Defence and Space.