Quest Joint Airlock

The Quest Joint Airlock, previously known as the Joint Airlock Module, is the primary airlock for the International Space Station. Quest was designed to host spacewalks with both Extravehicular Mobility Unit (EMU) spacesuits and Orlan space suits. The airlock was launched on STS-104 on July 14, 2001.

It was attached to the starboard CBM of the Unity during STS-104. The four external HP tanks were installed in pairs on two occasions.

Before Quest was attached, Russian spacewalks using Orlan suits could only be done from the Zvezda service module, and American spacewalks using EMUs were only possible when a Space Shuttle was docked, allowing the astronauts to use the Shuttle's airlock, located in its payload bay.^{[citation needed]} The arrival of Pirs docking compartment on September 16, 2001 provided another airlock from which Orlan spacewalks can be conducted.^{[citation needed]}