John Yembrick and Tracy Young, NASA's Shuttle Atlantis Begins Mission to the Space Station (2007)
“ This latest addition to the station's backbone will extend the right side of the truss and includes a new set of solar arrays. When unfolded, the 240-foot arrays provide additional power to the station in preparation for the arrival of new science modules from the European and Japanese space agencies. The crew also will retract a solar array to allow for the rotation of the new arrays to track the sun. ”
