Discovery's Cargo Arrives at Launch Pad for Final Flight, Ken Kremer

"Discovery's primary cargo is a new module for the International Space Station which will provide much needed storage space for the resident crew of the orbiting outpost. The module -or PMM - will be the last permanent addition to be contributed by the United States to the ISS. The secondary cargo element is the Express Logistics Carrier-4 which will house exterior space parts. The Permanent Multipurpose Module (PMM) - also named Leonardo - was transported inside a large shipping canister from the Space Station Processing Facility (SSPF) to the top of Launch Pad 39 A. The canister was then hoisted up to a holding position on the massive Rotating Service Structure (RSS) from which the cargo will soon be loaded into the shuttle payload bay."