André Borschberg, the pilot at the controls of the Solar Impulse 2 aircraft, has broken the world record for the longest solo flight. Borschberg has now been aloft in the solar-powered plane for more than 80 hours without refueling or touching down, breaking the 76-hour record set by Steve Fossett in 2006 on board the Virgin Atlantic Global Flyer. And Borschberg isn't done yet — the pilot and co-founder of Solar Impulse has another 40 hours in the air before he's due to reach his destination in Hawaii.

The solar-powered plane took off from Nagoya in Japan on the eighth stage of its 13-stage round-the-world trip earlier this week. The journey to Hawaii was previously set to begin in Nanjing, China, but bad weather conditions forced Borschberg to land in the Japanese city and postpone his record-breaking attempt. The entire circumnavigation of the globe was to be broken into 12 manageable stages, but with the unscheduled touchdown in Nagoya, is now set to be completed in 13 chunks. After Hawaii, Borschberg will take a well-earned rest from the cockpit, allowing co-pilot Bertrand Piccard to fly the solar-powered craft on to Phoenix, Arizona. From there, the pilots will tag-team their way across the United States, cross the Atlantic into Europe, before finally touching down in Abu Dhabi, where their journey began.

The plane still has 40 hours to go before it lands in Hawaii

In taking the longest leg of the flight so far, Borschberg volunteered to sit in an unpressurized, unheated cockpit for five days straight. "The first 24 hours were very technical", he said from his position high above the Pacific ocean, "but the second day was really getting me into the mission. It took me a while to create a relationship of trust with the airplane, which allows me to rest and eventually sleep by periods of 20 minutes with the autopilot. The experience of flight is so intense that I can only focus on the present moment and discover how to deal with my own energy and mindset."

In addition to breaking the solo flight record, the 80-hour journey has already broken all distance and duration records for solar aviation, helping Solar Impulse's stated desire to spread the word about renewable energy sources. "Can you imagine that a solar powered airplane without fuel can now fly longer than a jet plane!", Piccard said in response to the record-breaking flight. "This is a clear message that clean technologies can achieve impossible goals!" But it might be a while still before we're all flying solar planes — however tiresome a 10-hour flight in a modern airplane might be, a five-day voyage in a freezing box the size of a cupboard sounds worse.