海角大神

The Solar Impulse 2, the solar-powered airplane that began its round-the-world flight more than a year ago, took off on the final leg of its journey early Sunday.

"Just took off from Cairo to achieve the 1st round-the-world solar flight. A dream I have since 1999," pilot Bertrand Piccard tweeted once the Solar Impulse 2 was in the air.聽

The flight is part聽of a solar project, estimated to cost more than $100 million, that began in 2002 to promote a "vision that clean technologies and energy efficiency聽can reduce our emissions and improve our quality of life," according to the project's website.

"Clean technology is a huge opportunity that will create jobs, make profits and protect the environment," Mr. Piccard told Fox News earlier this year.

The Solar Impulse 2's voyage began last year, when the plane took off from Abu Dhabi, United Arab Emirates.聽As 海角大神's Jason Thomson reported:

Along the way, the Solar Impulse 2 encountered some unexpected challenges when its battery cells overheated after a nonstop flight lasting five days and five nights between Japan and Hawaii. The technical difficulties grounded the plane for nine months before it was able to resume its journey.聽

Now, according to a tweet from the Mission Control Center, the Solar Impulse 2 will finally land in Abu Dhabi after a flight from Cairo expected to last 48 to 72 hours.

While the round-the-world flight is coming to an end, the project is not, Mr. Piccard told Reuters.

"The project is a big promotion of clean technologies around the world and the legacy of Solar Impulse is the created international community," he said.聽

This report contains material from Reuters.聽