The Joint Airlock Module rests inside Atlantis's payload bay.

The Joint Airlock Module rests inside Atlantis’s payload bay. The module is the primary payload on mission STS-104, scheduled to be launched July 12 for the International Space Station. The module, which comprises a crew lock and an equipment lock, will be connected to the starboard (right) side of Node 1 Unity. Once installed and activated, the Airlock becomes the primary path for Space Station spacewalk entry and departure for U.S. spacesuits, which are known as Extravehicular Mobility Units, or EMUs. In addition, the Joint Airlock is designed to support the Russian Orlan spacesuit for EVA activity