International Space Station
Obverse view in November 2021 | |
International Space Station program emblem with flags of the original signatory states | |
| Station statistics | |
|---|---|
| COSPAR ID | 1998-067A |
| SATCAT no. | 25544 |
| Call sign | Alpha, Station |
| Crew |
|
| Launch | 20 November 1998 |
| Launch pad | |
| Mass | 450,000 kg (990,000 lb) |
| Length | 109 m (358 ft) (overall), 94 m (310 ft) (truss) |
| Width | 73 m (239 ft) (solar array) |
| Pressurised volume | 1,005.0 m3 (35,491 cu ft) |
| Atmospheric pressure | 1 atm (101.3 kPa; 14.7 psi) 79% nitrogen, 21% oxygen |
| Perigee altitude | 413 km (256.6 mi) AMSL |
| Apogee altitude | 422 km (262.2 mi) AMSL |
| Orbital inclination | 51.64° |
| Orbital speed | 7.67 km/s; 27,600 km/h; 17,100 mph |
| Orbital period | 92.9 minutes |
| Orbits per day | 15.5 |
| Orbit epoch | 16 August 16:19:30 |
| Days in orbit | 27 years, 9 months, 27 days as of 16 September 2026 |
| Days occupied | 25 years, 10 months, 14 days as of 16 September 2026 |
| No. of orbits | 158,233 as of 24 August 2026 |
| Orbital decay | 2 km/month (1.2 mi/month) |
| Statistics as of 22 December 2022 (unless noted otherwise) References: | |
| Configuration | |
Station elements as of 2023 (exploded view with the names of elements coloured by country) | |
The International Space Station (ISS) is a space station in low Earth orbit (LEO). It is the product of the International Space Station program and is operated by five partner space agencies: NASA (United States), Roscosmos (Russia), ESA (Europe), JAXA (Japan), and CSA (Canada). It is the first space station built, maintained and crewed through international cooperation and the largest human spacecraft ever constructed. It is an orbital research station, where scientific experiments in microgravity are conducted and the space environment is studied. Since 2 November 2000, it has hosted the longest continuous human presence in space. Alongside China's Tiangong, it is one of two currently operational space stations.
The station orbits between 51.64° north and south, at about 400 kilometres (250 miles) above Earth, below the Van Allen radiation belts and most space debris. Its orbit takes it at 7.67 km/s (27,600 km/h; 17,200 mph) roughly every 93 minutes around Earth, 15.5 times a day. Measuring 109 m (358 ft) (with solar arrays) by 73 m (239 ft), it is as large as a full-sized football or soccer field, and has a pressurised internal volume of 1,005 m3 (35,491 ft3), comparable to a Boeing 747 airliner.
The station is a modular space station divided into two main sections: the Russian Orbital Segment (ROS), developed by Roscosmos, and the US Orbital Segment (USOS), built by NASA, ESA, JAXA, and CSA. The Integrated Truss Structure connects the station's vast system of solar panels and radiators to its 16 major pressurized modules. These modules support scientific research, crew habitation, storage, spacecraft control, and airlock operations. The ISS has eight docking and berthing ports for visiting spacecraft. In total, the station consists of 43 different modules and elements. Crews visit via the Soyuz and Crew Dragon spacecraft, and previously the Space Shuttle. Cargo supply craft include Progress, Cargo Dragon, Cygnus, Automated Transfer Vehicle, and HTV-X.
The ISS is the political product of the development of international cooperation in space throughout the space age. The station combines two previously planned crewed Earth-orbiting stations: the United States' Space Station Freedom and the Soviet Union's Mir-2. The first ISS module was launched in 1998, with major components delivered by Proton, Soyuz and Space Shuttle launch vehicles. Long-term occupancy began with the arrival of the Expedition 1 crew on 2 November 2000. Since then, the ISS has remained continuously inhabited for 25 years and 318 days, the longest continuous human presence in space. As of August 2025, 290 individuals from 26 countries had visited the station.
Future plans for the ISS include the addition of at least one module, the Payload Power Thermal Module by Axiom Space, forming the commercial segment of the station. The station is expected to remain operational until the end of 2030, by which parts of it are to be used for Axiom Station and the Russian Orbital Service Station. After this the ISS is planned to be de-orbited using the US Deorbit Vehicle, but critique of this plan and the proposal of parking the station at a more stable higher orbit has gathered congressional support as of 2026.