First ultraviolet data collected from NASA’s Europa Clipper mission

The Southwest Research Institute-led Ultraviolet Spectrograph (UVS) aboard NASA’s Europa Clipper spacecraft has successfully completed its initial commissioning following the October 14, 2024, launch. Scheduled to arrive in the Jovian system in 2030, the spacecraft will orbit Jupiter and ultimately perform repeated close flybys of the icy moon Europa. Previous observations show strong evidence for a subsurface ocean of liquid water that could host conditions favorable for life.

Europa-UVS is one of nine science instruments in the mission payload, including another SwRI-led and developed instrument, the MAss Spectrometer for Planetary EXploration (MASPEX). The UVS instrument collects ultraviolet light to create images to help determine the composition of Europa’s atmospheric gases and surface materials.

“SwRI scientists started this process in January from NASA’s Jet Propulsion Laboratory. However, we had to evacuate due to the fires in southern California,” said SwRI Institute Scientist Dr. Kurt Retherford, principal investigator (PI) of Europa-UVS. “We had to wait until May to open the instrument’s aperture door and collect UV light from space for the first time. We observed a part of the sky, verifying that the instrument is performing well.”

SwRI has provided ultraviolet spectrographs for other spacecraft, including ESA’s Rosetta comet orbiter, as well as NASA’s New Horizons mission to Pluto, Lunar Reconnaissance Orbiter mission in orbit around the moon and Juno mission to Jupiter.

“Europa-UVS is the sixth in this series, and it benefits greatly from the design experience gained by our team from the Juno-UVS instrument, launched in 2011, as it pertains to operating in Jupiter’s harsh radiation environment,” said Matthew Freeman, project manager for Europa-UVS and director of SwRI’s Space Instrumentation Department. “Each successive instrument we build is more capable than its predecessor.”

Weighing just over 40 pounds (19 kg) and drawing only 7.9 watts of power, UVS is smaller than a microwave oven, yet this powerful instrument will determine the relative concentrations of various elements and molecules in the atmosphere of Europa once in the Jovian system. A similar instrument launched in 2023 aboard ESA’s Jupiter Icy Moons Explorer spacecraft, which will be studying several of Jupiter’s icy moons, gases from the volcanic moon Io and Jupiter itself. Having two UVS instruments in the Jupiter system at one time offers complementary science.

In addition to performing atmospheric studies, Europa-UVS will also search for evidence of potential plumes erupting from within Europa.

“Europa-UVS will hunt down potential plumes spouting from Europa’s icy surface and study them to understand what they tell us about the nature of subsurface water reservoirs,” said Dr. Thomas Greathouse, SwRI staff scientist and Europa-UVS co-deputy PI. “The instrument is working fabulously, and we’re excited about its ability to make new discoveries once we get to Jupiter.”

NASA’s Jet Propulsion Laboratory (JPL) manages the Europa Clipper mission for NASA’s Science Mission Directorate in Washington, D.C. The Europa Clipper mission was developed in partnership with the Johns Hopkins University Applied Physics Laboratory (APL), in Laurel, Maryland.