The JUICE mission is at the very beginning of its eight-year journey to Jupiter and its moons, but one of its science instruments is already misbehaving.

The European Space Agency’s Jovian probe is having difficulty deploying its Radar for Icy Moons Exploration (RIME) antenna, which remains “partially extended but still stowed away,” according to a statement by the space agency.

JUpiter ICy moons Explorer, or JUICE for short, launched on April 14 on a 12-year mission to study three of Jupiter’s icy moons: Europa, Ganymede, and Callisto. For its first two weeks in space, the spacecraft has been commissioning the different instruments on board. JUICE has already captured its first images using its monitoring cameras, deployed its solar array, and even got its first taste of science by deploying its magnetometer boom and recording a blip of the surrounding magnetic field.

When it came time to deploy its 52-feet-long (16 meters) radar antenna, however, things didn’t go as smoothly for JUICE. Mission controllers with ESA have been working to free the radar, which is currently at about a third of its fully intended length. “Every day the RIME antenna shows more signs of movement, visible in images from the Juice Monitoring Camera on board the spacecraft with a partial view of the radar and its mount,” ESA wrote in its statement.

A tiny stuck pin may be preventing the antenna from fully unfurling in orbit, the team suspects. They are considering different options on how to free the antenna, which could include an engine burn to “shake the spacecraft a little” and then turning the spacecraft round and round to warm its mount and radar, moving them from the cold shadows into the Sun’s light.

The RIME instrument is designed to probe the subsurface structure of Jupiter’s icy moons, exploring the potential for habitability beneath the surface. JUICE still has some time to figure out its radar antenna trouble before reaching Jupiter and its moons, which is scheduled to take place in 2031.

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