This text refers to items from 21 through 30.

Blazing a trail with solar power

1 In a hangar outside Zurich, engineers are paring

away at the obstacles to a very 21st century challenge: flying

a plane around the world powered by nothing but the rays of

4 the sun. If the Solar Impulse project goes to plan, in 2011 a

gangly aircraft with the wingspan of an Airbus A380 and the

weight of a compact car will attempt to circle the globe in

7 about a month at an average speed of 43 m.p.h. (70 km/h),

landing only five times along the way.

The challenge, says Piccard, is to keep going until

10 the next sunrise before the batteries are empty: “We have

very little margin of error from night into day. Each dawn

will be a moment of incredible suspense.” For the 2011

13 flight, he and Boschberg will do alternating stints of five

days and five nights between landings. A day on the ground

spent charging in the sunlight should be enough to get the

16 plane back into the air the next morning for another stage in

its globe-girdling journey.

It’s a delicate enterprise, complicated by

19 meteorological challenges and the ungainliness of a plane

this big and light. Even Piccard doesn’t envision solar planes

replacing today’s airliners anytime soon, but that’s not the

22 point. To reduce emissions, he believes, aviation will

eventually need to wean itself from fossil fuels. “To make

reasonable use of any alternative,” he says, “we have to

25 become lighter and more aerodynamic to reduce

consumption.” Solar Impulse promises to generate an array

of futuristic insights — and some old-fashioned thrills along

28 the way.

Internet: <www.time.com> (adapted).

In the text,

the word "stints" (l.13) refers to an unbroken period of time doing a certain job or ac...