Solar Impulse 2 to return to the skies

The longest non-stop solo aeroplane flight in aviation history is set to resume flying after entering "Mission Mode" for the next leg of its adventure from Hawaii to North America.

Solar Impulse 2 (Si2) has undergone two months of maintenance and training flights after engineers replaced batteries that overheated during a flight piloted André Borschberg from Nagoya to Hawaii, where it has been grounded since last July.

Since then, Borshberg and fellow Si2 pilot Bertrand Piccard have been training using a simulator in preparation for the remainder of the worldwide flight across the circumference of the earth.

Flying close to the sun

Solar Impulse chief executive Borschberg said in a statement: “As we experienced many times with Solar Impulse, obstacles often turn out to be opportunities for improvement. Ultimately, this time was used to recreate the strong mindset within the team to continue our adventure. It takes sometimes more time to build up the right spirit than to develop new technologies.”

Last year, Si2 conquered the skies using the sun’s power from Abu Dhabi, across Oman, India, Myanmar, China, and Japan before grounding in Hawaii. Following repair work, the flight will now complete its journey by flying over the Pacific Ocean to the USA, across either Southern Europe or Northern Africa before it returns to the departure point in Abu Dhabi.

Flight experts including air traffic controllers, meteorologists and mission engineers at the Mission Control Center in Monaco are currently searching for a “weather window” to identify the clearest flight paths.

Plane sailing

The next leg of the mission will be piloted by Piccard, who will head to one of four North American destinations – Los Angeles, Pheonix, the San Francisco area or Vancouver – with the landing site to be decided shortly before departure depending on the weather conditions. The following leg of the flight is yet to be decided.

Piccard said: “An airplane with perpetual flight endurance, without fuel, like the Solar Impulse is not only a first in the history of aviation, but also in the history of energy. The primary purpose of this adventure is to demonstrate that modern clean technologies can achieve the impossible and encourage everyone to use these same energy efficient solutions on the ground in their daily lives for mobility, construction, lighting, heating, cooling and more.”

On Wings of Waste

Last summer, Si2 broke the world record for distance and duration of solar aviation, flying continuously for more than 80 hours and travelling 6000km across the Pacific. The single-seater plane has a wingspan of 72 meters but weighs the same as a car at just 2,300Kg, due to its carbon fibre hull. More than 17,000 solar cells built into the wings charge lithium batteries during the day, to enable it to continue flying at night.

Si2’s return to the skies comes during an exciting period for the aviation industry. Last month, legendary broadcaster and naturalist Sir David Attenborough welcomed a planned flight across America in a plane powered by recycled plastic as a “sign of hope in a very depressing world”. Set for take-off in August, British-born pilot Jeremy Rowsell will fly more than 3,000 miles from San Francisco to Alaska in the pioneering ‘On Wings of Waste’ flight, which will use recycled plastic waste as aviation fuel. 

George Ogleby

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