Images

STEREO will not only see the sun, but will harness its energy to help power the twin spacecraft and their subsystems throughout the mission. Positioned like wings on a plane, these solar arrays have panels that absorb the sun's energy. Inside the launch vehicle the arrays will be folded so the observatories will fit inside. After they're separated from the launch vehicle in space, the arrays unfold and each spacecraft then measures more than 21 feet across.

Engineers in this picture are assembling one of the solar arrays. Click here to see an animation showing the solar panels being deployed.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory