Unity (ISS module)


The Unity connecting module, also known as Node 1, is the first U.S.-built component of the International Space Station. It connects the Russian and United States segments of the station, and is where crew eat meals together.
The module is cylindrical in shape, with six berthing locations facilitating connections to other modules. Unity measures in diameter, is long, made of steel, and was built for NASA by Boeing in a manufacturing facility at the Marshall Space Flight Center in Huntsville, Alabama. Unity is the first of the three connecting modules; the other two are Harmony and Tranquility.

Launch and initial berthing

Unity was carried into orbit as the primary cargo of the on STS-88, the first Space Shuttle mission dedicated to assembly of the station. On December 6, 1998, the STS-88 crew mated the aft berthing port of Unity with the forward hatch of the already orbiting Zarya module. This was the first connection made between two station modules.

Connecting modules and visiting vehicles

Unity has two axial and four radial Common Berthing Mechanism ports. In addition to connecting to the Zarya module, Unity connects to the U.S. Destiny Laboratory Module, the Z1 truss, the PMA-3, and the Quest Joint Airlock. During STS-120 the Harmony module was temporarily berthed to the port-side hatch of Unity. Tranquility, with its multi-windowed cupola, was attached to Unitys port side during the STS-130 mission, and PMM Leonardo was added to the nadir hatch during STS-133.
In addition, the Leonardo and Raffaello Multi-Purpose Logistics Modules were each berthed to Unity on multiple missions.
;Nadir
;Forward
PatchSpacecraftDockingUndocking'
STS-9627 May 1999
10:49:42 UTC
6 June 1999
02:02:43 UTC
STS-10120 May 2000
04:30 UTC
26 May 2000
23:03 UTC
STS-1068 September 2000
12:45:47 UTC
19 September 2000
07:56 UTC
STS-9211 October 2000
23:17:00 UTC
24 October 2000
20:59:47 UTC

  • Destiny, 2001–Present
;Aft
  • Zarya, 1998–Present
;Starboard
  • Quest, 2001-Present
;Port
  • Tranquility, 2010-Present
;Zenith
  • Z1 truss, 2000-Present

    Details

Essential space station resources such as fluids, environmental control and life support systems, electrical and data systems are routed through Unity to supply work and living areas of the station. More than 50,000 mechanical items, 216 lines to carry fluids and gases, and 121 internal and external electrical cables using six miles of wire were installed in the Unity node. It is made of aluminium and stainless steel. During the space station construction, a crew member placed two speed limit signs on the hatch in 2003, noting the orbital velocity in mph and km/h.
Prior to its launch aboard Endeavour, conical Pressurized Mating Adapters were attached to the aft and forward berthing mechanisms of Unity. Unity and the two mating adapters together weighed about. The adapters allow the docking systems used by the Space Shuttle and by Russian modules to attach to the node's hatches and berthing mechanisms. PMA-1 now permanently attaches Unity to Zarya, while PMA-2 provided a Shuttle docking port. Attached to the exterior of PMA-1 are computers, or multiplexer-demultiplexers, which provided early command and control of Unity. Unity also is outfitted with an early communications system that allows data, voice and low data rate video with Mission Control Houston, to supplement Russian communications systems during the early station assembly activities. PMA-3 was attached to Unitys nadir berthing mechanism by the crew of STS-92.

Other nodes

The two remaining station connecting modules, or nodes, were manufactured in Italy by Alenia Aerospazio, as part of an agreement between NASA and the European Space Agency. Harmony and Tranquility are slightly longer than Unity, measuring almost long in total. In addition to their six berthing ports, each can hold eight International Standard Payload Racks. Unity, in comparison, holds just four ISPRs. ESA built Nodes 2 and 3 as partial payment for the launch aboard the Shuttle of the Columbus laboratory module, and other ESA equipment.

Footnotes

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