Starboard Array Rotation Joint

The Starboard Array Rotation Joint, part of the S3 Truss Segment, tracks the Sun for the Starboard Side Solar Arrays as the Space Station orbits the Earth.  (This segment can also hold unpressurized logistics carriers and attached payloads.)  On the International Space Station the Starboard Array Rotation Joint will be launched with an array of solar cells known as the S4 Segment, providing a new power source to the station but not shown here.
