A one-of-a-kind solar-powered aircraft completed a two-month journey across the United States at just after 11pm EDT Saturday evening (3am GMT Sunday) when it landed at New York's JFK Airport.
The landing came several hours earlier than planned because of a tear that developed Saturday afternoon in the delicate wing of the aircraft. The tear didn't put the craft in immediate danger, but did prompt the flight crew to curtail the flight originally scheduled to end at 2am local time on Sunday. The early landing closed a runway at JFK, causing delays to some outgoing commercial flights, and also meant pilot André Borschberg didn't get to achieve his wish to fly around the Statue of Liberty in the plane.
Solar Impulse has the wingspan of a jumbo jet but weighs about the same as a family car. Coated with solar panels, the Swiss plane flies can theoretically stay aloft indefinitely, but its 35 mile per hour cruising speed means the entire trip would take many days to complete. So, to give the pilot a break, the aircraft flew in six stages, taking off in the early morning and landing late at night.
It embarked on the seven-city trip at dawn on May 3 when it soared into the sky above Silicon Valley from Moffett Field. From there, it flew to Phoenix, Dallas, St. Louis and Washington, D.C., from where it departed early Saturday morning.
The journey provided the team with valuable data on how the aircraft performs in several types of climate, particularly those not found in Europe.
"We had all these tornadoes in Texas, Oklahoma and Missouri," said Borschberg in an interview with IDG News Service on Saturday morning. He was speaking via satellite phone from the cockpit of the aircraft as it circled above the New Jersey shoreline to the south of New York.
"It was not easy to find a way through this difficult weather. I think we learned a lot on how to operate in a windy environment as well. That was part of the goal of this flight across America," he said.
Borschberg said the Solar Impulse team also learned something when the plane was left outside overnight in Cincinnati, rather than being kept inside the protective inflatable hangar that has followed it across the U.S.
"It was very foggy the following morning, we had quite a lot of condensation water everywhere. It really showed us a couple of weaknesses we had that will be modified in the next airplane," he said.
Preparations for that next airplane are already underway and it faces a much greater challenge: to fly around the globe powered by nothing but the Sun.
The team hopes to attempt that flight sometime in 2015.
The round-the-world aircraft is already being designed and one of the biggest changes will be to the facilities offered for the pilot.
"Our challenge now, having a sustainable airplane, is to develop a sustainable pilot," said Borschberg. "We're constructing a second airplane in Switzerland, which will be completely different from this perspective. Different cockpit, different instruments, different support for the pilot enabling him to fly many days and many nights. So that's a very important step. That's the first airplane that has an almost unlimited endurance."
Martyn Williams covers mobile telecoms, Silicon Valley and general technology breaking news for The IDG News Service. Follow Martyn on Twitter at @martyn_williams. Martyn's e-mail address is firstname.lastname@example.org