On April 9，2010，a solar-powered plane successfully made its first flight．It flew at a speed of 70 km/h at a height of 1，200 meters in the sky above Switzerland for 87 minutes．It is the first solar-powered plane in the world．A group of engineers，led by Bertrand Piccard，a well-known pilot，made this plane． The solar-powered plane is different from the planes that we usually see．The' plane has a thin body with two very big wings full of solar cells．It uses sunlight as its energy, but it was not easy to make such a plane．First of all，Bertrand Piccard and his group membe