The International Space Station is a large spacecraft where astronauts live, and it orbits Earth about 250 miles above the ground. NASA uses it to learn about both working and living in space, which might be able to help people go farther into space someday. It's also used as a science lab, and many countries have worked together to build it and use it.
It wasn't easy building the space station. It's made up of many pieces, and it was all put together in space by astronauts. In 1998, the very first piece of the International Space Station was launched into space, carried by a Russian rocket. Two pieces would follow after that. It wasn't until two years later that the space station was ready for people to live in. On Nov. 2, 2000, the first crew of astronauts moved into the International Space Station, and people have lived there ever since. More pieces would be added to it over the years, and it eventually was finished in 2011, thanks to NASA and its partners from all around the world.
The part of the International Space Station where people live and work is as big as a house, and it has five bedrooms, two bathrooms, science labs from the United States, Europe, Japan, and Russia, and even a gym that has a big bay window. Currently, six people are able to live there at a time. The entire space station, including the huge solar panels on both sides, is as wide as a football field! In fact, the space station is big enough that if you look up at just the right place in the sky at the right time, you can see it with your own eyes.
The International Space Station is important for many reasons. We can learn a lot from what goes on on the space station, and part of that is learning about what happens to people when they live in space. Spending a long time out of Earth's gravity can do a lot of weird things to your body, and we need to know about these effects if we're going to be able to send astronauts to Mars someday. The record for the most amount of time spent at the space station at one time is currently held by two people, Scott Kelly of the United States and Mikhail Kornienko of Russia, who both spent almost a year there.