A clean, structured overview: orbit, mass, modules, crew capacity, and key milestones
Five-agency partnership and long-duration microgravity lab.
Five space agencies from 15 countries operate the ISS. It has been continuously crewed since Nov 2000 and serves as a long-duration research platform in low Earth orbit.
Crew capacity
7
Continuous; 3-13 during handovers
Mass
419,725 kg
Varies with visiting vehicles
Modules
16
Pressurized modules in the assembled complex
Altitude range
370-460 km
Low Earth orbit band
Orbit and path
Inclination
51.6 deg
Period
about 90 min
Speed
about 7.7 km/s
Orbits per day
16
Dimensions and volume
Length
51 m
Width
109 m
Across solar arrays
Pressurized volume
1,005 m3
Habitable volume
388 m3
Modules and layout
Core and service
Russian segment
Zarya provides power and storage; Zvezda provides life support and propulsion.
Labs
Science
Destiny (US), Columbus (ESA), Kibo (JAXA), and Nauka (Roscosmos).
Nodes
Connectivity
Unity, Harmony, and Tranquility link modules and systems.
Airlock and observation
EVA and Earth views
Quest airlock supports spacewalks; Cupola provides panoramic views.
Docking hub
Ports
Prichal adds additional Russian docking ports.
Selected modules shown. The ISS includes more elements.
Timeline
Zarya launches
First ISS element placed in orbit.
Unity joins
First U.S. module installed and connected to Zarya.
Zvezda arrives
Service module adds life support and propulsion.
Continuous crew begins
Expedition 1 starts uninterrupted human presence.
Destiny lab
U.S. laboratory module installed.
Canadarm2
Robotic arm arrives for assembly and maintenance.
Quest airlock
Dedicated airlock enables U.S. segment spacewalks.
Harmony node
Node 2 connects major science modules.
Columbus lab
ESA laboratory installed.
Kibo lab
JAXA experiment module installed.
Poisk module
Russian docking and EVA support module installed.
Tranquility node
Life support systems and crew facilities expand.
Cupola
Panoramic observation module added.
Rassvet module
Docking and cargo module installed.
PMM
Permanent Multipurpose Module adds storage volume.
BEAM
Expandable habitat technology demo installed.
Bishop airlock
Commercial airlock expands external research.
iROSA 2B/4B
First roll-out solar arrays installed.
Nauka
Russian multipurpose laboratory module installed.
Prichal
Docking hub with multiple ports added.
iROSA 3A/4A
Second set of roll-out solar arrays installed.
iROSA 1A/1B
Latest roll-out solar arrays installed.
Science and life aboard
Research focus
Microgravity research
Materials, fluids, combustion, and physics experiments in long-duration microgravity.
Human health
Study long-duration effects on the body and develop countermeasures.
Earth observation
Monitor Earth systems, disasters, and climate from orbit.
Technology demos
Test life support, robotics, and deep-space systems.
Life and operations
Exercise routine
Crew exercise about 2 hours per day to reduce muscle and bone loss.
Water recovery
Water Recovery System reduces delivered water by about 65 percent.
Sunrises per day
The station sees about 16 sunrises and sunsets every 24 hours.
Good to know
House-sized interior
Six sleeping quarters, two bathrooms, a gym, and a 360-degree view bay window.
Global coverage
Orbit passes over more than 90 percent of Earth's population.
Assembly flights
Major modules arrived on 42 assembly flights (37 Shuttle, 5 Russian Proton/Soyuz).
All values are approximate and vary with configuration.