Schedule mapped out to final space shuttle launch

The powerful booster rockets for the final space shuttle launch continue to be stacked segment-by-segment inside the Vehicle Assembly Building in preparation to propel Atlantis skyward this summer. Technicians began piecing the solid motors together on March 29 when the base for the left-hand booster was hoisted atop the shuttle's mobile launching platform. The aft segment of the right-hand booster followed suit on March 31. The bottom segments of each booster get anchored to the platform by explosive bolts that pop at liftoff to release the shuttle. More

(Source: Space Flight Now - Apr 12)