Switzerland’s Solar Impulse has an ambitious goal: The privately funded project wants to be the first team to circumnavigate the globe using a solar-powered fixed wing aircraft flown by a pilot. After an unexpected battery issue forced the mission to abort half-way through, the plane has been repaired, and the team, funded by entrepreneurs André Borschberg and Bertrand Piccard, is close to resuming their record-breaking flight.

The Solar Impulse 2 (Si2) departed Abu Dhabi, United Arab Emirates in March of 2015 and flew successfully across Asia to Japan. The flight was grounded in Japan shortly due to weather before continuing onto Hawaii. During this last leg across the Pacific Ocean, Borschberg flew 4,481 miles over 117 hours, 52 minutes, setting world records for the longest solar-powered flight by time and by distance. Unfortunately, the long flight had a deleterious effect on the aircraft. The Si2 experienced a thermal failure with its batteries that caused the global trip to come to a quick end. The plane was grounded in July 2015 and underwent repairs in Hawaii.

After months of uncertainty, the Solar Impulse 2 is now ready to continue its journey across the globe. As reported on the Solar Impulse blog, the Si2 took its first post-repair training flight on February 26th following months of storage. The plane took off from Hawaii’s Kalaeloa airport, flew to 8,000 feet over the Pacific Ocean and remained in the air for 90 minutes. During its flight, the plane passed all maintenance checks, including stabilization and cooling tests, with flying colors. “It was a true relief to see Si2 back in the Hawaiian sky after the past months of uncertainty,” said Piccard.

With a successful test flight under its belt, the Solar Impulse team is looking forward to resuming their circumnavigation starting in April 2016. This target date gives them time to analyze the data collected from this first flight and conduct additional flights if needed.  April also provides them with enough daylight to power the solar-powered aircraft on multi-day flights.