STS-104, International Space Station (ISS) assembly mission 7A, marks the completion of the initial assembly phase of ISS. The 7A crew will install, activate, and perform the first space walk from the Joint Airlock. The Joint Airlock will enable crews to perform space walks in either United States or Russian spacesuits while recovering over 90 percent of the gases that were previously lost when airlocks were vented to the vacuum of space. This patch depicts the launch of Space Shuttle Atlantis and the successful completion of the mission objectives as signified by the view of the ISS with the airlock installed. The astronaut symbol is displayed behind Atlantis as a tribute to the many crews that have flown before. The hard work, dedication, and teamwork of the airlock team is represented by the ISS components inside the payload bay which include the Joint Airlock and four high pressure gas tanks containing nitrogen and oxygen. In the words of a STS-104 crew spokesperson, "The stars and stripes background is symbolic of the commitment of a nation to this challenging international endeavor and to our children who represent its future."
http://spaceflight.nasa.gov/gallery/images/shuttle/sts-104/html/sts104-s-001.html
NASA