MADRID (AP) - An experimental solar-powered plane has taken off from Madrid en route to Morocco in a bid to complete its first transcontinental flight.

The single-seat aircraft fitted with 12,000 solar cells is the size of a jumbo jet. Organizers said in a statement it is due to arrive in the Moroccan capital Rabat late Tuesday night after leaving Spain before dawn.

Solar Impulse arrived from Switzerland in late May on the first leg of the journey.

The mission is being described as a final dress rehearsal for a round-the-world flight with a new and improved plane in 2014.

The project began in 2003 and is estimated to cost about $100 million over 10 years.

The two-leg Europe to Africa trip covers 2,500 kilometers (1,554 miles).