International Space Station: Partners, modules and key experiments – GKToday

the International Space Station (ISS) is a typical research laboratory operating in low Earth orbit at an altitude of about 400 km. Assembled in orbit beginning in November 1998, it represents one of the largest international scientific collaborations in history. The station completes about 16 orbits around the Earth every 24 hours, and travels at a speed of approximately 28 thousand kilometers per hour. It provides a unique microgravity environment for sustained, long-term scientific research across the physical sciences, biology, human physiology, astronomy and Earth observation.

Partner agencies and operational structure

Five space agencies representing 15 countries are jointly managing the project International Space Station. Governance relies on intergovernmental agreements and bilateral memorandums of understanding that define legal jurisdiction, administrative responsibilities, and resource allocation.

Core participating space agencies

• National Aeronautics and Space Administration (NASA): Manages the United States’ comprehensive orbital sector, integrated communications, and primary laboratory infrastructure.
• State space company Roscosmos (Roscosmos): Operates the Russian orbital sector, providing station propulsion, orbit maintenance, and crew transportation systems.
• European Space Agency (ESA): Representing 11 European member countries, the project contributes to the main pressurized research units and automated supply vehicles.
• Japan Aerospace Exploration Agency (JAXA): The station’s largest science laboratory complex has been developed and operated.
• Canadian Space Agency (CSA): Providing the station’s basic external automated systems used in maintenance, assembly and seizure of vehicles.

Basic modules and orbital architecture

The station spans 109 meters from end to end and weighs approximately 430 metric tons. It is functionally divided into two main parts: the Russian Orbital Segment (ROS) and the United States Orbital Segment (USOS).

Russian Orbital Segment (ROS)

• Zarya (functional charging block): It was launched in November 1998 as the first module of the International Space Station. It provided primary electrical power, propulsion and storage during early station assembly.
• Zvezda (server module): She joined in July 2000 to provide life support systems, crew living quarters, main engine propulsion, and flight control functions.
• Search and dawn: Small research modules designed for scientific experiments, cargo storage, and docking ports for Soyuz and Progress spacecraft.
• Naoka (Multi-Purpose Laboratory Unit): It will dock in 2021 as a major research module in Russia, expanding the science space and adding a custom robotic arm built by the European Space Agency.

United States Orbital Segment (USOS)

• Unit (node ​​1): It was launched in December 1998 as the first item manufactured in the United States. It serves as a link between the Russian and American sectors.
• Destiny Lab: It was annexed in February 2001 as a US Core Research Facility for microgravity materials, life sciences, and physics experiments.
• Quest Joint Airlock: It supports spacewalks using both US Extravehicular Mobility Units (EMU) and Russian Orlan suits.
• Harmony (Node 2) and Calm (Node 3): Utility centers that provide power distribution, life support, environmental control systems, and crew exercise equipment.
• Columbus Laboratory: Contributed by ESA in 2008 to European Fluid Physics, Biology and Materials Science research.
• Kibo (Japanese experimental unit): It was developed by JAXA as the largest unit on the station. It features a pressurized laboratory, a non-pressurized outdoor facility for space exposure experiments, and a robotic arm.
• dome: An observation unit with seven windows that provides a direct view of Earth observations, astronomical photography and robotic operations.
• BEAM (Bigelow Expandable Activity Module): An expandable habitation module was installed in 2016 to test inflatable structures in low Earth orbit.

Structural and technical collapse

Key scientific experiments and techniques

More than 3,000 scientific experiments from more than 100 countries have been conducted aboard the station.

Physics and materials science

• Alpha Magnetic Spectrometer (AMS-02): A particle physics detector mounted on the outer truss structure measures cosmic rays to search for antimatter and dark matter.
• Cold Atom Laboratory (CAL): Bose-Einstein condensates are produced at temperatures close to absolute zero, allowing the observation of quantum phenomena revealed by gravity.
• Neutron Star Interior Composition Explorer (NICER): It measures X-ray emissions from pulsars to study states of dense matter.

Human physiology and life sciences

• Twin study (NASA): Astronaut Scott Kelly has been compared during his year-long space mission with his identical twin on Earth, detailing genetic, telomeric and physiological adaptations to spaceflight.
• Tissue chips in space: Microfluidic devices carrying human cells are exposed to microgravity to model disease progression and accelerate drug discovery.
• Vegetables (vegetable production system): Plant growth studies under microgravity to develop sustainable food production methods for deep space missions.

Deorbit plan for the station and future relocation

Space agencies plan to operate the station until 2030. Structure deterioration, atmospheric drag and aging electronics dictate an orderly retirement to avoid an uncontrolled return. NASA has awarded a contract to SpaceX to build the customized US Deorbit Vehicle (USDV). This specialized spacecraft will dock with the station, perform retrograde thrust burns, and guide the 430-ton structure to a remote area in the South Pacific near Point Nemo. After the station’s retirement, the human presence in low Earth orbit will move toward commercial space stations and China’s Tiangong Station.

Basic facts about the International Space Station

• The station’s first module, Zarya, was launched aboard a Russian Proton rocket on November 20, 1998.
• Continued human occupation of the station began on November 2, 2000, with Expedition 1.
• The station orbits the Earth at an average altitude of 400 kilometers and an inclination of 51.6 degrees.
• Solar arrays mounted on the integrated truss structure generate up to 120 kilowatts of electrical power.
• The station’s compressed area is about 916 cubic metres, the equivalent of a six-bedroom house.
• Canada’s contribution, Canadarm2, is a 17-metre robotic arm capable of moving heavy loads along the length of the outer truss.
• The Russian segment uses Soyuz spacecraft for crew transport and unmanned Progress vehicles for orbital reboost and refueling operations.
• SpaceX Crew Dragon and Boeing Starliner provide commercial crew transportation services under NASA’s Commercial Crew Program.
• Point Nemo in the South Pacific serves as the target site for the station’s controlled ocean impact after 2030.