SLIM, Japan’s first mission to the lunar surface, reached its goal this Friday, but the spacecraft’s solar panels are not capable of generating enough electricity after landing.

The probe’s solar panels are not generating electricity as planned on the lunar surface, Japan Aerospace Exploration Agency (JAXA) officials said during a post-landing news conference. If the issue is not fixed soon, SLIM could go silent forever. Its battery can support operations on the Moon for only a few hours, they added.

The SLIM (Intelligent Moon Research Lander) lander, nicknamed the “lunar sniper,” touched down about 20 minutes after midnight Japan time (15:20 UTC). Designed to land within a radius of just 100 meters of its target, the lander was launched in September. Japan has become the fifth country to reach the Moon in a controlled manner, after the US, Russia, China and India.

SLIM reached its various milestones during descent, and the lander communicated with Earth during and after its landing. However, JAXA could not immediately confirm SLIM’s status after landing. About an hour later, the agency reported on the probe’s power problems.

It’s unclear why the solar cells don’t work, JAXA officials said. But it’s unlikely they were damaged during landing, because the rest of SLIM’s hardware appears to be fine and functional. According to JAXA, the lander may not be facing the sun as expected.

SLIM aimed to study its surroundings, an area of ​​Mare Nectaris (“Sea of ​​Nectar”), which lies about 15 degrees south of the lunar equator, using its onboard spectrometer. Data from the instrument could reveal information about the composition of the area, which in turn could shed light on the formation and evolution of the moon, but it won’t have the chance to do so unless SLIM’s solar arrays come online, reports.

SLIM also carried two small rovers, a small hopper called LEV-1 and a ball-shaped craft known as LEV-2. (“LEV” is short for “Lunar Excursion Vehicle”). These small robots were designed to deploy from the SLIM mothership, collect some data of their own, and take photographs.

Data indicates that both LEV-1 and LEV-2 deployed as planned, JAXA officials said during today’s press conference, adding to the mission’s accomplishments.