A solar-powered airplane landed in California on Saturday, completing a risky, three-day flight across the Pacific Ocean as part of its journey around the world.

Pilot Bertrand Piccard landed the Solar Impulse 2 in Mountain View, in the Silicon Valley south of San Francisco, at 11:45 pm following a 62-hour, nonstop solo flight without fuel. The plane taxied into a huge tent erected on Moffett Airfield where Piccard was greeted by project's team.

The landing came several hours after the Piccard performed a flyby over the Golden Gate Bridge as spectators watched the narrow aircraft with extra wide wings from below.

"I crossed the bridge. I am officially in America," he declared as he took in spectacular views of San Francisco Bay.

Piccard and fellow Swiss pilot Andre Borschberg have been taking turns flying the plane on an around-the-world trip since taking off from Abu Dhabi, the capital of the United Arab Emirates, in March 2015. It made stops in Oman, Myanmar, China, Japan and Hawaii.

The trans-Pacific leg was the riskiest part of the plane's global travels because of the lack of emergency landing sites.

The aircraft faced a few bumps along the way.

The Solar Impulse 2 landed in Hawaii in July and was forced to stay in the islands after the plane's battery system sustained heat damage on its trip from Japan. The team was delayed in Asia, as well. When first attempting to fly from Nanjing, China, to Hawaii, the crew had to divert to Japan because of unfavorable weather and a damaged wing.

A month later, when weather conditions were right, the plane departed from Nagoya in central Japan for Hawaii.

The plane's ideal flight speed is about 28 mph, though that can double during the day when the sun's rays are strongest. The carbon-fiber aircraft weighs more than 5,000 pounds, or about as much as a midsize truck.

The plane's wings, which stretch wider than those of a Boeing 747, are equipped with 17,000 solar cells that power propellers and charge batteries. The plane runs on stored energy at night.

Solar Impulse 2 will make three more stops in the United States before crossing the Atlantic Ocean to Europe or Northern Africa, according to the website documenting the journey.

The project, which began in 2002 and is estimated to cost more than $100 million, is meant to highlight the importance of renewable energy and the spirit of innovation. Solar-powered air travel is not yet commercially practical, however, given the slow travel time, weather and weight constraints of the aircraft.

(China Daily 04/25/2016 page15)