The International Space Station
The International Space Station (ISS) is the biggest object ever flown in space and can often be seen from Earth! It travels around the Earth at an average speed of 28 800 km/h, completing 16 orbits per day, as it flies on average 400 kilometres above us. 15 countries, including the USA, Russia, Japan, Canada and many ESA member states worked together to build the Station Since it was first built in 1998, more than 250 people from over 20 different countries have visited the ISS.
The largest part of the ISS is a long, central beam called the truss that has 8 huge solar array wings (each with two solar panels) attached. The modules where the astronauts live and work are attached to the centre of the truss. Europe’s biggest ISS project is the Columbus science laboratory, where astronauts can carry out scientific experiments in weightless conditions. Many different types of experiments can take place both inside and outside this space laboratory.
ESA also made the Automated Transfer Vehicle (ATV), a series of spacecrafts without people inside which gave spare parts as well as food, air and water to the ISS. The cargo craft delivered food, fuel, equipment and other supplies between 2008 and 2014.
The Advanced Closed Loop System (ACLS) is an important part of the ISS because it helps our astronauts breathe by turning carbon dioxide, which astronauts breathe out, into oxygen! For many years, oxygen was made from water (which is made of hydrogen and oxygen) that was brought from Earth. But with this new system, astronauts can save enough water to fill a big bathtub every year (and save lots of money)! This system is really important for future space missions to the Moon and Mars, as it helps astronauts live in space longer without needing as many supplies from Earth.
Once astronauts arrive on the ISS, they usually spend about six months there, conducting science experiments and taking care of the station. The ISS has more living space than a normal six-bedroom house, including sleeping quarters, bathrooms, a gym, and a special ESA-built window called the Cupola that gives them a 360-degree view of Earth.
In total, more than 3,600 researchers have conducted over 2,500 experiments aboard the ISS. Astronauts also have some free time to look out the window, chat with family, and enjoy hobbies!
Last modified 22 January 2025