International Space Station

ISS module Node 2 manufacturing and processing in the Space Station Processing Facility
The ISS was slowly assembled over more than a decade of spaceflights and crews.

The ISS is a modular space station. Modular stations can allow modules to be added to or removed from the existing structure, allowing greater flexibility.

The Joint Airlock (also known as "Quest") is provided by the U.S. and provides the capability for ISS-based Extravehicular Activity (EVA) using either a U.S. Extravehicular Mobility Unit (EMU) or Russian Orlan EVA suits. Before the launch of this airlock, EVAs were performed from either the U.S. Space Shuttle (while docked) or from the Transfer Chamber on the Service Module. Due to a variety of system and design differences, only U.S. space suits could be used from the Shuttle and only Russian suits could be used from the Service Module. The Joint Airlock alleviates this short-term problem by allowing either (or both) spacesuit systems to be used. The Joint Airlock was launched on ISS-7A / STS-104 in July 2001 and was attached to the right hand docking port of Node 1. The Joint Airlock is 20 ft. long, 13 ft. in diameter, and weighs 6.5 tons. The Joint Airlock was built by Boeing at Marshall Space Flight Center. The Joint Airlock was launched with the High Pressure Gas Assembly. The High Pressure Gas Assembly was mounted on the external surface of the Joint Airlock and will support EVAs operations with breathing gases and augments the Service Module's gas resupply system. The Joint Airlock has two main components: a crew airlock from which astronauts and cosmonauts exit the ISS and an equipment airlock designed for storing EVA gear and for so-called overnight "campouts" wherein Nitrogen is purged from astronaut's bodies overnight as pressure is dropped in preparation for spacewalks the following day. This alleviates the bends as the astronauts are repressurized after their EVA.

The crew airlock was derived from the Space Shuttle's external airlock. It is equipped with lighting, external handrails, and an Umbilical Interface Assembly (UIA). The UIA is located on one wall of the crew airlock and provides a water supply line, a wastewater return line, and an oxygen supply line. The UIA also provides communication gear and spacesuit power interfaces and can support two spacesuits simultaneously. This can be either two American EMU spacesuits, two Russian ORLAN spacesuits, or one of each design.

Columbus is a science laboratory that is part of the ISS and is the largest single contribution to the station made by the European Space Agency.

Dextre, like many of the station's experiments and robotic arms, can be operated from Earth, allowing tasks to be performed while the crew sleeps.

The Integrated Truss Structure serves as a base for the station's primary remote manipulator system, the Mobile Servicing System (MSS), which is composed of three main components:

Made by Bigelow Aerospace. In August 2016 Bigelow negotiated an agreement with NASA to develop a full-sized ground prototype Deep Space Habitation based on the B330 under the second phase of Next Space Technologies for Exploration Partnerships. The module is called the Expandable Bigelow Advanced Station Enhancement (XBASE), as Bigelow hopes to test the module by attaching it to the International Space Station.

Nanoracks, after finalizing its contract with NASA, and after winning NextSTEPs Phase II award, is now developing its concept Independence-1 (previously known as Ixion), which would turn spent rocket tanks into a habitable living area to be tested in space. In Spring 2018, Nanoracks announced that Ixion is now known as the Independence-1, the first 'outpost' in Nanoracks' Space Outpost Program.

If produced, this centrifuge will be the first in-space demonstration of sufficient scale centrifuge for artificial partial-g effects. It will be designed to become a sleep module for the ISS crew.

The interactions between the components of the ISS Environmental Control and Life Support System (ECLSS)
ISS new roll out solar array as seen from a zoom camera on the P6 Truss
Soyuz TM-31 being prepared to bring the first resident crew to the station in October 2000
Dragon and Cygnus cargo vessels were docked at the ISS together for the first time in April 2016.
Rendering of the ISS Visiting Vehicle Launches, Arrivals and Departures.

Sleep is regularly disturbed on the ISS because of mission demands, such as incoming or departing spacecraft. Sound levels in the station are unavoidably high. The atmosphere is unable to thermosiphon naturally, so fans are required at all times to process the air which would stagnate in the freefall (zero-G) environment.

Graph showing the changing altitude of the ISS from November 1998 until November 2018
Animation of ISS orbit from 14 September 2018 to 14 November 2018. Earth is not shown.

Under specific conditions, the ISS can be observed at night on five consecutive orbits. Those conditions are 1) a mid-latitude observer location, 2) near the time of the solstice with 3) the ISS passing in the direction of the pole from the observer near midnight local time. The three photos show the first, middle and last of the five passes on 5–6 June 2014.

A Commemorative Plaque honouring Space Station Intergovernmental Agreement signed on 28 January 1998