The sun-powered plane known as Solar Impulse 2 successfully completed the most dangerous leg of its historic attempt to fly around the world—but not without consequences. The difficult journey overheated the aircraft’s batteries, causing severe damage, the team of Swiss explorers piloting the plane announced on Wednesday. As a result, they will be grounded until next spring.

Solar Impulse 2 landed in Kapolei, Hawaii  on July 3, following a five-day flight that took off from Nagoya, Japan. The plane crossed more than 4,000 miles of the Pacific Ocean, traversing the same desolate region where Amelia Earhart disappeared 77 years ago.

During the first day of the trip, however, the batteries that store the solar-powered aircraft’s energy began to overheat