Solar plane takes off for 24-hour test flight

Geneva: A Swiss team, planning to circle the globe in a solar-powered plane, have begun a 24-hour test flight that will see the aircraft powered through the night by energy collected from the sun.

The plane, with its 80-metre wingspan, took off from Payerne airfield in Switzerland shortly before 7am on Wednesday, after an equipment problem delayed a previous attempt last week.

The Solar Impulse team, says pilot Andre Borschberg, will take the prototype to an altitude of 8,500 metres by Wednesday evening.

They will then slowly descend through the night and aim for a dawn landing.