NASA and its partners have supported humans continuously living and working in space since November 2000. A truly global endeavor, the International Space Station has been visited by more than 290 people from 26 countries and a variety of international and commercial spacecraft. The unique microgravity laboratory has hosted more than 4,000 experiments from over 5,000 researchers from 110 countries. The space station also is facilitating the growth of a commercial market in low Earth orbit for research, technology development, and crew and cargo transportation.
After a quarter of century of human presence in orbit, the station remains a symbol of international cooperation and a proving ground for humanity's next giant leaps to the Moon and, eventually, Mars.
The microgravity environments aboard the space station unlocks discoveries that benefit life on Earth and prepare humans for deep space missions. NASA's Human Research Program (HRP) works to understand the changes astronauts face aboard the orbital outpost and to develop interventions to keep crews healthy before, during, and after flight.
Astronauts aboard the station exercise for roughly two hours a day to protect bone density, muscle strength, and the cardiovascular system, but the longer they are in microgravity, the harder it can be for the brain and body to readapt to gravity's pull. After months in orbit, returning astronauts often describe Earth as heavy, loud, and strangely still. Some reacclimate within days, while other astronauts take longer to fully recover.
Through HRP-led studies, scientists track these changes and test solutions-from improved exercise regimens to medical monitoring and nutritional strategies. The results inspire new medical technologies, while teaching scientists how the human body adapts to long-duration spaceflights-knowledge that helps keep astronauts healthy on future missions.
The space station continues to be a critical platform for sharpening skills, technology, and understanding that will prepare humanity to return to the Moon with NASA's Artemis campaign and journey on to Mars and beyond.
Since space presents an entirely new physical environment with a distinct set of challenges, the orbiting laboratory is uniquely positioned to support research and preparations not possible on Earth. That includes:
- Mastering techniques for basic tasks like drinking water, sleeping, exercising, and handling various materials.
- Developing solutions to microgravity-induced changes to and challenges for the human body.
- Testing reliable technologies and self-sustaining ecosystems necessary for deep space travel, from life support systems to in-orbit agriculture and 3D printing of materials.
- Refining techniques and procedures for data and imagery collection and analysis.
