གཟའ་ཟླ་བ། ༢༠༢༤/༠༧/༡༥

Pilot to Attempt Night Flight in a Solar-Powered Plane

plane through the night. The aircraft took off from Payerne, Switzerland, Wednesday morning after an equipment problem delayed a previous attempt last week.

A Swiss pilot is aiming to fly a solar-powered airplane through day and night, without fuel.

The Solar Impulse HB-SIA is a single-seater, solar-powered plane. Its wings are as long as those of an Airbus A340 - a whopping 63 meters - and the top side of those wings are covered with a skin of solar cells. During daylight hours, the plane will be taking in the Sun's rays and charging its batteries. The goal is for the plane to continue flying through the night using the energy stored inside those batteries to keep its motors running.

The Solar Impulse team had planned for a night flight last week, but they had to postpone that take-off when a critical piece of equipment malfunctioned. At that time, the founders of the project, Bertrand Piccard and Andre Borschberg, expressed their disappointment as well as their hope.

Solar Impulse Chairman Bertrand Piccard:

"You have to understand that the airplane is completely experimental," said Bertrand Piccard. "It is the type of airplane that has never flown in the past, so we need to assist the pilot from the ground, but we also need to assist the airplane itself."

Piccard explained that high-tech equipment will transmit data from the plane to a team on the ground. That equipment, like everything on the 1,600-kilogram aircraft, is lightweight. And, Piccard added, the equipment records, in his words, "absolutely everything."

"The team will know about vibrations in the wings, about the position of the flight controls, about the efficiency of the solar cells, all the energy that gets in, all the energy that gets out," he said.

Piccard initiated the project in 1999, setting his sights on such solar-powered flight after he circumnavigated the world in a balloon.

Solar Impulse's Chief Executive Officer Andre Borschberg is the pilot for this historic night flight. He explained that these solar-powered flight plans have a limited window of opportunity because the project relies on stable weather and long, sunny days.

"July is a very good month so we'd like to use this month to do - and we plan to do - two flights through the nights, and we really will fight to make them successfully," said Andre Borschberg.

The Solar Impulse team says the plan is for Borschberg and the carbon fiber plane to spend all day Wednesday slowly ascending to an altitude of 8,500 meters. About two hours before sunset Wednesday evening, the sun's rays will no longer be strong enough to supply the solar cells with energy, and the plane will begin a slow descent to an altitude of 1,500 meters. If all goes according to the plan, the plane will use the energy stored in its batteries to fly until sunrise.

Piccard said the fact that they had to postpone the take-off last week is not a problem in the longterm.

"You know, aviation didn't need just a couple of weeks to go from the Wright Brothers to the moon landing," said Piccard. "It's a lot of time. It's a lot of problems to be solved. It's an adventure, you know."

In its test flights, the plane has managed to stay aloft for 14 hours. And, if successful on this attempt, the Solar Impulse HB-SIA will be the first plane to ever harness the power of the sun to fly through the night.