It’s taken more than 500 days and overcome countless problems, but the epic journey of Solar Impulse 2 is finally complete.
The experimental solar-powered plane made aviation history when it landed in Abu Dhabi before dawn on Tuesday, after successfully circumnavigating the globe without using a single drop of fuel.
The record-breaking mission flown by two Swiss pilots, Bertrand Piccard and Andre Borschberg, evoked memories of the likes of the Wright brothers and Amelia Earhart – aviation pioneers with a similar spirit of adventure and innovation.
Solar Impulse: Mission control
Borschberg is an ex-fighter pilot and MIT engineering graduate, while Piccard – who also made the first non-stop round-the-world balloon flight in 1999 – comes from a long line of adventurers.
His grandfather, Auguste Piccard, was a physicist with a passion for record-breaking balloon flights, while his father, Jacques Piccard, was a renowned oceanographer and diver. In 1960, together with U.S. Navy diver Don Walsh, the duo became the first men to dive the seven miles (11 kilometers) to the bottom of the Mariana Trench in the western Pacific, the deepest part of the world’s oceans.
The journey by Solar Impulse 2, one of the project’s two operational aircraft, was no less of a challenge.
With a wingspan greater than that of a Boeing 747 Jumbo jet, Solar Impulse is fitted with four electric engines powered by renewable energy from the sun.
The aircraft is covered with 17,248 solar panels, has on-board batteries that allow it to fly at night, and weighs about as much as an SUV.
It was Piccard who landed the aircraft on the last leg of the journey; a flight from Cairo to the UAE that lasted more than 48 hours.
He climbed out of the cockpit after touching down and was immediately embraced by Borschberg as the two men realized the magnitude of their feat.
“I’m not exhausted. I’m so happy,” Piccard told CNN after the flight.
“You know, with Andre, we have worked for 15 years in that project to make it happen. Finally, after all the doubts, all the problems, all the setbacks, we’re successful. It’s not the moment to be tired,” he said.
“When I saw him coming on the same runway, in the same direction that I took off 15 months ago – and you have time because this is an airplane that flies slowly – you have time to enjoy that,” said Borschberg. “This was two fantastic minutes. I wanted them to last hours. I was thrilled by this. It was extraordinary,” he added.
Records smashed
Solar Impulse 2 began its epic round-the-world journey in March, 2015.
Piccard and Borschberg took turns flying the single-seater aircraft on different legs of the route, and they were in a cockpit not much bigger than that of a Formula One race car.
They had to fly, sleep for 20 minutes at a time, eat and relieve themselves in their seat. “It was a house in the sky,” Piccard told CNN while flying over Saudi Arabia.
They hopscotched across the globe, flying west to east from Abu Dhabi. They made planned landings in countries including Oman, India, China and the U.S., covering an estimated 24,800 miles (40,000 kilometers).
Flying the first solar-powered plane around the world wasn’t the only record the two men set.
In a flight that lasted more than 117 hours, Borschberg also made the world’s longest solo flight during a five-day, five-night crossing of the vast Pacific Ocean.
It was a moment of human achievement: for almost five days and five nights Borschberg piloted the plane wearing an oxygen mask as it climbed 8,000 meters high (five miles) during the day, so the aircraft’s solar cells could soak up enough energy to propel it through the night.
Bad weather, burned batteries
It was far from easy – or quick.
Solar Impulse 2 flew at an average speed of 75 kilometers (46 miles) per hour, slower than an ordinary passenger car.
The pilots encountered several setbacks and challenges along the way. A series of frustrating weather delays in China slowed progress for weeks, followed by an unexpected diversion to Japan where the aircraft was damaged on the tarmac by a storm.
Miss Liberty welcomes Solar Impulse 2 plane
And the record-breaking Pacific Ocean crossing came at a cost. The plane’s batteries overheated so badly that the trip had to be delayed in Hawaii by 10 months.
It was only after he landed that the team discovered how bad the damage was.
“We made a mistake with our batteries,” Piccard said after the plane touched down in July last year. “It was a human mistake.”
It was a mistake that took more than nine months to fix, but fix it they did. A new cooling system for the batteries that could be manually operated by the pilot was installed, and the mission benefited from a further $20 million injection in funding to continue.
Viable alternative?
Piccard came up with the idea for the Solar Impulse mission in 2002 and collaborated with Borschberg the following year. Their goal: to prove to the world that renewable energy is a viable alternative to fossil fuels – even in the skies.
Over the course of the next decade, they built and tested several prototypes of their current plane powered by the sun.
The Solar Impulse project, which cost $170 million in total, was funded mostly by private sponsors.
By 2012, the two men had successfully completed a solar-powered flight across the continental United States, which is when they realized their latest round-the-world journey was possible.
However, it may be some time before solar-powered flights take off commercially.
The Solar Impulse 2 was built with extremely lightweight carbon fiber material, which means it only has enough lift to carry one person.
Solar Impulse 2's round-the-world journey
And while the Solar Impulse 2 didn’t use any fuel, the pilot who wasn’t at the helm – as well as a portion of the 90-strong support staff – had to fly commercially to each successive destination.
Piccard admitted the team’s biggest accomplishment doesn’t involve world records – or even the flight itself. Real success in their drive to implement renewable energy around the world, he said, will come only if others carry on their torch.
“Solar Impulse has made a great achievement,” Piccard announced to a crowd in Abu Dhabi just moments after exiting the cockpit.
“Now it’s your turn to take it further.”
CNN’s David Molko contributed to this report.
