An anonymous reader writes: After stalling on the island of Oahu for almost 10 months, the Solar Impulse 2 continues its journey to fly across the world with no fuel. Today, it took off from Hawaii to California piloted by Swiss explorer and psychiatrist Bertrand Piccard. Since the plane travels at about the same speed as a car, it'll take 62 hours to complete the flight across the Pacific to the San Francisco Bay area, some 2,500 miles (4,000 kilometers) away. The pilots and team call this test "the moment of truth," as they've experienced weather delays slowing down the progress. It was originally scheduled to land in Abu Dhabi, where it started its journey in March 2015, by the end of last summer. The plane had to be grounded for nine months while the batteries were being fixed. Now the Solar Impulse 2 has new batteries, a new cooling system that can be manually operated by the pilot, and $20 million in fresh funding to keep the mission up and running, according to CNN.