A space station is a large spacecraft where astronauts live and work for weeks or months at a time while orbiting Earth. Unlike rockets that blast into space and return in a few days, space stations stay up there, circling the planet every 90 minutes or so at speeds around 17,500 miles per hour.

The International Space Station, or ISS, is the most famous space station. It's about as long as a football field and has living quarters, laboratories, and exercise equipment. Astronauts aboard conduct experiments that would be difficult or impossible to do on Earth, like studying how plants grow in microgravity or how materials behave in the vacuum of space. They also exercise for hours each day because without gravity, their muscles and bones would weaken.

Life on a space station means floating everywhere, sleeping in bags attached to walls, and eating food from sealed pouches. Looking out the window, astronauts see Earth moving beneath them, with sunrises and sunsets happening about every 45 minutes.

Space stations involve partnerships between different countries. The ISS includes cooperation between the United States, Russia, Europe, Japan, and Canada, with scientists from different countries working together hundreds of miles above Earth.