Solar Flight Challenges Everything


On the 7th leg (Nanjing - Hawaii) of the first around the world solar flight, Solar Impulse 2’s (SI2) pilots and project team are challenging assumptions and themselves at the edges of human endeavour in ways only true pioneers do. There are also incredible amounts of hope and romance in this amazing adventure. SI2 is a masterpiece of aeronautical and solar powered engineering. Putting their lives on the line, pilots André Borschberg and Bertrand Piccard, are pushing the boundaries of battery storage technology. They are also pushing their luck because they need fair weather to charge SI2’s batteries and facilitate the passage of this streamlined and incredibly light aircraft flying at 140 kph.

While preparing himself in Nanjing to fly solo to Hawaii, Borschberg was in a reflective mood. “I think I am now the adult I was dreaming I would be when I was a kid,” Borschberg said in a television interview in Nanjing.

At 72 metres the SI2’s wingspan is longer than a Boeing 747’s but at 2.3 tonnes it’s more than 100 times lighter with capacity to carry a solo pilot. Up to Nanjing, Borschberg and Piccard had shared the flying with each of them taking on 20 hour flights.

In daylight hours SI2 flies above the clouds to ensure its batteries are fully recharged. As the sun sets it glides to conserve energy, the batteries then power SI2 through the night. When the sun rises SI2’s batteries are down to 10%; the challenge of charging them up and increasing altitude starts all over again.

The 7th leg Nanjing to Hawaii is already proving to be a different order of magnitude altogether of courage and endurance to other legs so far. Approximately 36 hours in, weather forecasts became the focus of another moment of truth for SI2.

Only hours before the point of no return, after which Borschberg’s only option would have been to bail out into the sea, mission control made the decision to land at Nagoya airport in Japan – only 40 hours into the planned 5 day 6 night flight – but still the longest ever achieved in a solar aircraft measured by both time and distance.

SI2 has many heavy duty partners, including Solvay, Schindler, Omega, ABB, United Arab Emirates, Bayer, Toyota and Google. Yet even with this support and the most advanced technologies available, it’s the nature of the mission which matters most.

In harnessing the Sun’s energy by navigating the Earth’s weather SI2 is writing new chapters in the race towards clean energy.

SI2’s flight – fight response to climate change challenges everything.