The world's first round-the-world flight to be powered solely by the sun's energy made history on Tuesday as it landed in Abu Dhabi, where it first took off on an epic 25,000-mile (40,000-kilometer) journey that began more than a year ago.
Since its March 2015 take off, the Swiss-engineered Solar Impulse 2 has made 16 stops across the world without using a drop of fuel to demonstrate that using the plane's clean technologies on the ground can halve the world's energy consumption, save natural resources, and improve quality of life.
The aircraft is uniquely powered by 17,248 solar cells that transfer energy to four electrical motors that power the plane's propellers. It runs on four lithium polymer batteries at night. The plane's wingspan stretches 236 feet (72 meters) to catch the sun's energy.
At around 5,070 pounds (2,300 kilograms), the plane weighs about as much as a minivan or mid-sized truck. An empty Boeing 747, in comparison, weighs 400,000 pounds (180,000 kilograms). To help steady it during takeoffs and landings, the plane was guided by runners and bicyclists.
Over its entire mission, Solar Impulse 2 completed more than 500 flight hours, cruising at an average speed of between 28 mph (45 kmh) and 56 mph (90 kmh). It made stops in Oman, India, Myanmar, China, Japan, the United States, Spain, Italy, Egypt and the United Arab Emirates. Its North American stops included California, Arizona, Oklahoma, Ohio, Pennsylvania and New York.
The carbon-fiber plane is a single-seater aircraft, meaning its two Swiss pilots — Piccard and Borschberg— had to take turns flying solo for long days and nights. The pilots would rest a maximum of 20 minutes at a time, repeating the naps 12 times over each 24-hour stretch.
It took 70 hours for Piccard to cross the Atlantic Ocean, which was the first by a solar-powered airplane.
Borschberg's flight over the Pacific Ocean at 118 hours — about five days and five nights — shattered the record for the longest flight duration by an aircraft flying solo.
The project is estimated to cost more than $100 million. The UAE-based Masdar, the Abu Dhabi government's clean-energy company, was a main sponsor of the flight. There were more than 40 additional sponsors, including Omega, Belgian chemical company Solvay, Swedish-Swiss automation corporation ABB, Swiss manufacturer Schindler, Google and Moet Hennessey, among others.
Source: Associated Press