Unity

Description

Unity (also known as Node 1) is a six-sided aluminum connecting passageway to living and work areas of the International Space Station. It is the first major U.S.-built component of the station, and was delivered by the space shuttle STS-88. The shuttle crew docked Unity with Zarya, then conducted spacewalks to attach various power, communication, and data lines between Zarya, the PMAs, and Unity, thereby making the ISS an operational entity. Later, before releasing Unity from its connection to the shuttle, the shuttle Endeavor fired thrusters and climbed to about 248 miles, 5-1/2 miles higher than before. During the lifetime of the ISS, other such boosts will be needed to maintain the station in the desired orbit. The initial orbital parameters of the ISS (Zarya + Unity combined) were approximately: period 93 min, apogee 410 km, perigee 390 km, and inclination 51.6 deg. The size of the combination is approximately 77,000 pounds (35,000 kg) and 77 feet (23 m) tip-to-tip.

Unity has two Pressurized Mating Adapters (PMAs), one attached to either end. Including the PMAs, it is about 11 m (36 feet) long, and has a diameter of about 5 m (16 feet). PMA 1 is now permanently mated to the FGB and PMA 2 will be used for orbiter dockings and crew access to the station. Unity also will contain an International Standard Payload Rack used to support on-orbit activities once activated after the fifth Shuttle/Station assembly flight.

In addition to its connection to Zarya and its shuttle docking port, Unity has six other hatches that will eventually provide connecting points for the Z1 truss exterior framework, the U.S. laboratory module; an airlock; the cupola; Node 3; and a Multi-Purpose Logistics Module (MPLM). For further details of the component modules, see their separate descriptions in the NSSDC information system, the NASA web site http://spaceflight.nasa.gov/ and the URLs below.

http://station.nasa.gov/station/assembly/index.html (A search page)

http://station.nasa.gov/station/assembly/elements/fgb/ (Zarya - 1998-067A)

http://station.nasa.gov/station/assembly/elements/node1/ (Unity - 1998-069F)

http://www.estec.esa.int/spaceflight/index.htm

http://www.estec.esa.int/spaceflight/zarya.htm (ISS)