91É«ÇéƬ

The largest solar-powered plane took its maiden flight in Hawaii last week.
The pilotless Helios reached an altitude of 23,000 metres and is expected to set
new altitude records of more than 30,000 metres later this summer. Designed by
NASA and AeroVironment of California, Helios has a single 74-metre wing
plastered with solar cells and 14 propellers. It should be able to stay aloft
for months at a time and can be easily landed for repairs. That could make it
the perfect “poor man’s satellite” for weather observations, studying the
Earth’s surface and telecommunications, says programme manager John Hicks.…