Renewable Dream

A piloted helium-filled balloon will attempt to cross the Atlantic from Dakar in Senegal to Martinique powered only by renewable energy.

Windream One (see artist's impression above) hopes to prove that it is technologically possible to cover 5,000km (just over 3,000 miles) flying night and day using sources of energy drawn from the sea, the sun and the wind.

The craft is 28.5m long and the balloon has a capacity of 900 cubic metres. It is guided by a 'chien de mer', a curved carbon foil which will run under the water's surface.

It is linked to the balloon's nacelle by a cable whose length can be adjusted from 20-50m and which acts as a keel. This helps the crew control the flightpath by allowing the balloon to follow ocean currents.

Between February and March next year when the crossing is to take place, ocean currents running in the craft's intended direction are strong and should pull it along, aided by the wind or the craft's propeller when the wind is weaker.