Unity Node 1
Unity Node (top) attached to the Zarya Module. This photo of the embryonic International Space Station was taken after the undocking of Space Shuttle Endeavour during STS-88. Image credit: NASA.
The Unity Node is a connecting passageway to living and work areas of the International Space Station. It was the first major U.S.-built component of the station. Unity Node was delivered during STS-88 on Space Shuttle Endeavour in December 1998. The Pressurized Mating Adapter 1 was prefitted to its aft port. The crews conducted three space walks to attach Pressurized Mating Adapter 1 to the Zarya Control Module. This was the second International Space Station Assembly Flight and was designated 2A.
In addition to its connection to Zarya, Unity serves as a passageway to the U.S. Laboratory Module and an airlock. It has six hatches that serve as docking ports for the other modules.
Unity Node 1 is 5.5 meters (18 feet) long, 4.6 meters (15 feet) in diameter, and fabricated of aluminum. It contains more than 50,000 mechanical items, 216 lines to carry fluids and gases, and 121 internal and external electrical cables using 9.7 kilometers (6 miles) of wire.