The Solar Impulse I is made for one passenger and receives its energy entirely from the sun. It has an automatic take-off system and is capable of staying in the air for days. Development started in 2003 at the technical university of Lausanne. Its maiden flight was in the summer of 2009 and in 2010 the plane first made a flight of more than 24 hours. Solar Impulse broke records for longest and highest manned solar powered aircraft. One of the key design elements of the Solar Impulse is its huge wingspan, which maximizes area which can be fitted with solar panels. A drawback of such large wings is the vulnerability to turbulence. At night the plane is propelled by the energy that was stored in the batteries at daytime. Most of the plane is made out of carbon fiber laminate to decrease weight.