Designed by the crew members, the STS-92 patch symbolizes the second mission to carry U.S.-built elements to the International Space Station (ISS) for assembly. The black silhouette of the Space Shuttle Discovery stands out against the deep blue background of space in low Earth orbit. In the foreground in gray is a profile view of the ISS as it appears when the shuttle and crew arrive, with the station consisting of the Unity node, its two pressurized mating adapters (PMA), the Zarya functional cargo block, the Zvezda service module, and the Progress cargo vehicle.
Following the shuttle's rendezvous and docking, the ISS configuration will be augmented by the two elements delivered by Discovery–the Z1 truss and PMA-3. These two elements, depicted in red, will be installed using the shuttle's robot arm and be connected to ISS during four spacewalks. The multi-national nature of both the STS-92 crew and the ISS are reflected in the multi-colored Astronaut Office symbol.
http://spaceflight.nasa.gov/gallery/images/shuttle/sts-92/html/sts092-s-001.html
Space Flight Awareness (SFA) Program (Source PDF)
NASA