Long-range solar Plane stars around-the-world Trip (VIDEO)
The first attempt to send a solar-powered aircraft around the world started at 3:12am UTC in the United Arab Emirates and scheduled to return there five months later.
The plane has a similar wingspan to the Airbus A340 airliner. Under the wing are four nacelles, each with a set of lithium polymer batteries, a 10 hp (7.5 kW) motor and a twin-bladed propeller. To keep the wing as light as possible, a customised carbon fibre honeycomb sandwich structure is used. 11,628 photovoltaic cells on the upper wing surface and the horizontal stabilizer generate electricity during the day. These both propel the plane and charge its batteries to allow flight at night, theoretically enabling the single-seat plane to stay in the air indefinitely.
The aircraft's major design constraint is the capacity of the lithium polymer batteries. Over an optimum 24-hour cycle, the motors can deliver a combined average of about 8 hp (6 kW), roughly the power used by the Wright brothers' Flyer, the first successful powered aircraft, in 1903. In addition to the charge stored in its batteries, the aircraft uses the potential energy of height gained during the day to power its night flights.