Like an airplane, the Chinese spaceship Shenzhou-7 has a pair of wings when it's in orbit. But these wings aren't for flying. They're used for converting solar energy into electricity to power the spacecraft.

The panels are the biggest parts of the spacecraft, with a span 10 meters wide.

From the camera circling the spacecraft, we can see these solar panels working for the first time. The panels are the biggest parts of the spacecraft, with a span 10 meters wide. There is a solar panel on each of the spacecraft's wings, which unfold when the spacecraft is in orbit.

Qin Wenbo, Deputy Commander of Shenzhou-7, said, "The solar panels can unfold in two minutes after the separation of the spacecraft and the rocket. They can be rotated to obtain maximum solar reflection, regardless of the angle the spacecraft has to the sun."

After the panels adjust to face the sun, they're able to start powering the spacecraft.

Qin Wenbo said, "As long as there is sunlight, the panels can supply power to the spacecraft. There is also a battery to store extra electricity for when there is no sunlight."

The vessel circles the Earth once every 90 minutes and has to withstand vast temperature differentials of up to 180 degrees centigrade. The ultraviolet radiation and particle collision are harmful to the panels. These require the materials used to be able to contract and expand.

Qin Wenbo said, "Any chip in the panels could make a part of the panel lose its efficiency. They can distribute some extra electricity and ensure the safety of the panels."

To allow the panels to obtain maximum solar reflection, scientists enable it to rotate through 360 degrees. The number of chips on the panels is also maximized. These techniques combine to give the craft all the energy it needs in space.

(CCTV.com October 5, 2008)