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International Space Station

Humanity's flagship orbital outpost

Program leads
NASA, Roscosmos
Launch Date
20 November 1998
Crew aboard
Current Expedition

The International Space Station (ISS) is a permanently crewed, multinational space laboratory in low-Earth orbit. Continuously staffed since 2 November 2000, it is the longest-running space station program of all time, and consistently cited among the world's most ambitious engineering projects. Boasting a pressurized volume of 932 cubic meters, the ISS has an interior space equivalent to 24 shipping containers and with regular supply missions can indefinitely host up to 7 crewmembers.

The station is typically staffed by dual 3-person crews assigned to overlapping six-month missions, with each unique complement of 6 people composing a numbered Expedition (each 3-person crew will serve on two Expeditions during their stay). NASA and Roscosmos have also experimented with one-year crews, and may do so again in the future.

Current Crew

Soyuz MS-12, launched 14 March 2019

Soyuz MS-12 crew prior to launch

NASA / Victor Zelentsov

Soyuz MS-12 crew prior to launch
In the Integration Building at the Baikonur Cosmodrome in Kazakhstan, ISS crew members Christina Koch of NASA (left), Alexey Ovchinin of Roscosmos (center) and Nick Hague of NASA (right) pose for pictures in front of the Soyuz MS-12 spacecraft March 10 during final pre-launch inspections.

The station is currently between crew rotations and has just 3 astronauts aboard, after the return of Soyuz MS-11 on 25 June 2019. Soyuz MS-13, carrying NASA's Andrew Morgan, ESA's Luca Parmitano, and Roscosmos' Alexander Skvortsov, is scheduled for launch on 20 July 2019.

Major milestones


The station's altitude averages just over 400 kilometers. Earth's atmosphere continually drags it down. Mission controllers reboost its altitude regularly using either engines on the Zvezda service module or on visiting spacecraft. The station’s high, 51.64-degree orbital inclination carries it over 90 percent of the world's population, and its large size and reflective solar panels make it easy to spot from even brightly lit cities. You can sign up to receive text or email alerts from NASA when the station is visible from your location.

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Science and research

Science and research aboard the ISS generally fall into 4 categories:

NASA publishes annual highlights of station research that include links to research papers for major station investigations, as well as metrics for peer-reviewed papers related to ISS science. Data from some physical science investigations can be accessed through NASA's Physical Sciences Informatics System.

The 2005 NASA Authorization Act designated the ISS as a National Laboratory, opening it up to research by other federal entities and the private sector. The station’s National Lab activities are managed by the Center for the Advancement of Science in Space, CASIS.

The ISS also offers a means of cooperation for five of the world’s major space agencies: NASA, Roscosmos, ESA, JAXA, and CSA. Station astronauts regularly videoconference with students around the world.

ISS facts

The ISS as of June 2017

NASA / Wikipedia

The ISS as of June 2017
See source file for more information.

Explore the ISS using Google Street View

External resources


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