Unity (ISS module)

Unity

Unity as pictured by Space Shuttle Endeavour shortly after it was berthed to Zarya in December 1998
Module statistics
COSPAR ID	1998-069F
Part of	International Space Station
Launch date	4 December 1998, 08:35:34 UTC
Launch vehicle	Space Shuttle Endeavour
Berthed	6 December 1998 (Zarya forward)
Mass	11,612 kg (25,600 lb)
Length	5.47 m (17.9 ft)
Diameter	4.57 m (15.0 ft)

Unity, also known as Node 1, is the first U.S.-built component of the International Space Station (ISS). This cylindrical module, constructed of steel by Boeing for NASA, serves as the critical link between the orbiting laboratory's Russian Orbital Segment and US Orbital Segment.

Unity was launched on 4 December 1998, aboard the Space Shuttle Endeavour on STS-88. Two days later it was berthed to the previously launched Zarya module, marking the first connection between ISS components. Its six Common Berthing Mechanism (CBM) locations (forward, aft, port, starboard, zenith, and nadir) facilitate connections to other modules. At launch, two CBM locations were fitted with Pressurized Mating Adapters (PMA), one of which enabled the mating with Zarya.

Measuring 4.57 metres (15.0 ft) in diameter and 5.47 metres (17.9 ft) in length, Unity was built at NASA's Marshall Space Flight Center. It is the first of three connecting modules, joined by Harmony and Tranquility.