The International Space Station is a home and a laboratory. Astronauts live and work there while it orbits Earth. It has six sleeping quarters, two bathrooms and a gym. Each crew member has an assigned cabin. A window module called the Cupola has seven windows. They can look out at Earth from the windows.

A rocket lifts astronauts and their spacecraft off the ground. It burns fuel. It pushes hot gas out of its engine. Rocket scientists call the law behind liftoff Newton's third law. For every action there is an equal and opposite reaction. A rocket has to go faster than 28,000 kilometers an hour to reach low Earth orbit.

You need a strong science or technical education. NASA asks for a master's degree in a STEM field. You must pass the astronaut physical. New NASA astronauts learn basic skills for about two years. They learn at Johnson Space Center. Astronauts practice spacewalks in a huge pool of water. It is the closest you can get to microgravity on Earth.

Astronauts wear spacesuits for spacewalks outside the station. Space has no air. It is dangerous without a suit. A spacesuit has a helmet that protects the head. It also has gloves and boots. It gives them oxygen to breathe while they work in space. They tie their tools to their suits or workstation. The tools do not float away.

Earth's gravity still pulls on the space station. At that height it is only about 10 percent weaker than on the ground. The station and everything in it are falling around Earth together. That is why astronauts float. It is not because there is no gravity up there. The space station moves about 28,800 kilometers an hour. One trip around Earth takes about 92 minutes. The astronauts see 16 sunrises and 16 sunsets every day.

The space station cleans and recycles water from sweat and breath. Astronauts drink the water. There is no shower on the station. They wash with wet wipes. They use a shampoo that needs no rinsing. A space toilet has a hose with a fan that sucks waste away. Leg restraints hold astronauts on the seat.

Apollo 11 carried three men. They were Neil Armstrong, Michael Collins and Buzz Aldrin. It launched on July 16, 1969. Armstrong became the first person to walk on the Moon. It was July 20, 1969. Aldrin joined him. While they were on the Moon, Michael Collins stayed in orbit. His ship was the command module Columbia. Apollo astronauts collected rock and soil on the Moon. They brought it back to Earth.

Words to know

• laboratory: science workplace
• orbit: circle around
• restraints: straps
• station: place in space

The short version

Astronauts reach space on rockets, which work by pushing hot gas out of the engine. They live and work on the International Space Station, which orbits Earth. One trip around takes about 92 minutes. The astronauts float because they and the station are falling around Earth together.

Quick facts

• Five space agencies from 15 countries run the International Space Station together.
• The station moves about 5 miles a second, and one trip around Earth takes about 92 minutes.
• Astronauts on the station see 16 sunrises and 16 sunsets every day.
• On July 20, 1969, Neil Armstrong became the first person to walk on the Moon.