An experimental solar-powered plane landed safely today after completing its first 24-hour
test flight.
The record feat brings it one step closer to the makers’ ultimate aim of circling the globe using only energy from the sun.
The plane, with a 207-foot wingspan, touched down at Payerne airfield about 31 miles south west of the Swiss capital Bern earlier this morning.
The Solar Impulse team said the plane’s 12,000 solar cells managed to store enough energy during the day to last through the night. They said it proves the plane can stay in the air non-stop around the clock.
The prototype four-engine aircraft was flown by Andre Borschberg, a former fighter jet pilot from Switzerland.
A total of six years under development, the plane has already carried out two short but successful test flights, the last above Payerne in April when it spent 87 minutes in the air and reached a height of 1,200 metres.
"The intention of this mission is to demonstrate the potential of renewable energy and clean technologies," says Bertrand Piccard, one of the two initiators of the project who himself carried out the first non-stop round-the-world flight in a hot-air balloon just 11 years ago.
Claude Nicollier, a four-times astronaut and head of the craft's test flight programme, said the revolutionary project excited him as much as the space flights in which he had taken part.
Solar Impulse is ultimately expected to attain an average flying speed of 70 kilometres an hour and reach a maximum altitude of 8,500 metres.
The project's budget is 100 million Swiss francs (€75 million), 80 million francs of which has been secured from sponsors, according to spokeswoman Rachel de Bros.
Belgian chemicals company Solvay, Swiss watchmaker Omega, part of the Swatch group, and German banking giant Deutsche Bank, are the three main sponsors.
Ecole Polytechnique Federale de Lausanne, a leading Swiss research university, is acting as scientific and technological adviser for the project.