Atlantis will deliver the Joint Airlock to the International Space Station on the STS-104 mission, giving station crewmembers the ability to conduct spacewalks using either U.S. or Russian spacesuits. The airlock also will vent less precious air into space than the shuttle airlock.

The airlock is a critical space station element because of design differences between American and Russian spacesuits. American suits will not fit through Russian-designed airlocks. During a series of integration tests, the Russian suits were connected to the airlock to assure that they worked together. The airlock is specially designed to accommodate both suits, providing a chamber where astronauts from every nation can suit up for spacewalks to conduct science experiments and perform maintenance outside the station.

Once the airlock is carried into space aboard Atlantis, the astronaut crew, using the station's newly installed robotic arm, will secure it to the starboard side of the Unity node.

The airlock serves two key purposes: to keep air from escaping when the hatch to space is opened and to regulate the air pressure before an astronaut enters or leaves the ISS. It has two compartments: the crew lock, from which astronauts will enter and leave the station; and the equipment lock, where the spacewalkers will change into and out of their suits and stow all necessary gear.

The airlock was designed and built by Boeing at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala. Boeing-MSFC manufactured the equipment lock pressure shell, mated the equipment lock with the crew lock, installed all subsystems, and successfully performed airlock qualification testing.

The airlock was shipped to the Kennedy Space Center last September aboard NASA's "Super Guppy" cargo aircraft. There it underwent leak testing and ground processing while multi-layer insulation and debris shields were installed on its exterior.















Airlock Specifications
Material: Aluminum
Length:          5.5 meters (18 ft.)
Diameter: 4 meters (13 ft.)
Weight:          6,064 kilograms (13,368 lbs.)
Volume: 34 cubic meters (1,200 cu ft.)
Cost: $164 million, including tanks