- The ISS orbits Earth at an altitude of approximately 400 kilometers (250 miles)
- Follows a path inclined 51.6 degrees to the equator, allowing it to pass over most of Earth's populated regions
- Completes one orbit every 90-93 minutes
Components:
- Several interconnected modules, each with specific functions
- Central module: Zarya module; Russian-built, launched in 1998
- U.S. modules: Unity, Destiny, Quest Joint Airlock, Leonardo (Permanent Multipurpose Module)
- Russian modules: Zvezda (Service Module), Poisk (Mini-Research Module 2), Rassvet (Mini-Research Module 1), Nauka (Multipurpose Laboratory Module), Prichal (Node Module)
- International partners' modules: Columbus (European Space Agency), Kibo (Japan Aerospace Exploration Agency), Canadarm2 (Canadian Space Agency)
Power Generation:
- Solar arrays: Eight arrays convert sunlight into electrical energy
- Russian-built solar arrays attached to Zarya and Zvezda modules
- U.S.-built solar arrays on Unity, Z1 truss, P3/P4 truss, and S3/S4 truss
- Batteries: Store excess power for use during eclipse periods
Life Support Systems:
- Provides oxygen, water, food, and waste management
- Oxygen generation: electrolysis of water to produce oxygen and hydrogen
- Water recycling: wastewater is treated and recycled for drinking, hygiene, and other uses
- Food: delivered by visiting spacecraft, stored on ISS
Communication:
- S-band: primary system for communication with ground stations, data transfer, and voice communication
- Ku-band: used for real-time video and television transmission
- UHF: supports two-way voice communications between ISS and Earth, as well as between astronauts doing spacewalks
Guidance and Propulsion:
- Main engines: located on the Zvezda module, used to adjust ISS's orbit
- Reaction control system (RCS): smaller thrusters used for attitude control and maneuvering
- Orbital maneuvering system (OMS): consists of a set of thrusters used for larger adjustments to ISS's orbit
Docking Ports:
- Located on various modules, allow visiting spacecraft (such as Soyuz, Progress, Dragon, and Cygnus) to dock and transfer crew and cargo
Science and Research:
- Conducts experiments in various fields including biology, physics, materials science, astronomy, meteorology, and Earth observation
- Microgravity environment allows for unique research opportunities
Astronauts and Crew:
- Typically hosts a crew of six astronauts or cosmonauts from different countries
- Crew rotates every few months, with new members arriving and others returning to Earth
- Astronauts conduct experiments, perform maintenance tasks, and operate the station's systems
