You could be forgiven for thinking that the days when flying was a frontier science are well and truly over, but not so, as the Solar Impulse had its maiden flight recently. A flying machine no longer seems an eccentric idea but the aim of Solar Impulse is to fly using only solar power.

"It needs a very big wingspan with high aerodynamic efficiency in order to maintain a slow speed, which in turn cuts energy consumption. The aeroplane has a wingspan of 64 metres, comparable to that of an Airbus 340, but it weighs only 1600 kilograms, about as much as a car. This combination allows us to fly with the average energy consumption of a small motorcycle. Solar planes have existed in the past but they could only fly during the day: what they demonstrated was the limits of solar power, whereas we want to demonstrate the potential. We have 400 kilograms of lithium batteries to give us energy to fly at night." Bertrand Piccard tells new Scientist.

To prove that Solar Impulse can, theoretically, fly continuously without the need to refuel, Piccard hopes to circumnavigate the globe by 2013. Before that, a transatlantic flight is being planned. So how long would London to New York take? Well, probably about 4 to 5 days!