Low Earth Orbit

International Space Station

A permanently crewed orbital laboratory where research, operations, and international cooperation run every day.

Mission context

How the ISS works day to day

A permanently crewed orbital laboratory where multiple agencies run science, technology demonstrations, and long-duration human-spaceflight operations.

What the ISS is

The ISS is a modular station in low Earth orbit assembled over many years by an international partnership led by NASA and Roscosmos with major contributions from ESA, JAXA, and CSA. It serves as both a science platform and an operational testbed for deep-space mission planning.

What crews do onboard

  • • Microgravity research (biology, medicine, fluid physics, materials)
  • • Technology demos for exploration systems and life support
  • • Maintenance, robotics operations, and occasional EVA/spacewalks
  • • Earth observation and educational outreach

Operations rhythm

Crew rotations, cargo deliveries, and timeline planning are coordinated from multiple control centers. Mission planning balances science time, hardware reliability, visiting vehicle traffic, and crew health constraints.

Quick facts

Orbit type

Low Earth orbit

Typical altitude

~400 km

Orbital period

~90 minutes

Partners

NASA, Roscosmos, ESA, JAXA, CSA