Space stations are usually made up of several modules that are sent into orbit one at a time, and then assembled once in space. Space stations allow the crew to work in space for long periods of time in conditions in space capsules and the space shuttle are cramed, space stations are adapted for longer stays in space. Rockets or the space shuttle bring supplies of air and food to the space station and often a replacement crew. Some space station, such as the Russian Mir, stayed up for many years and their crews remained in space for mounths at a time.
FACT FILE
If you blow up a balloon and let it go without tying a knot in the neck, the air will rush out very quickly. When the air goes out one way it pushes the balloon the other way - just like a rocket!
resources: Tell me why (Chancellor Press)
image 1: https://hips.hearstapps.com/pop.h-cdn.co/assets/15/45/2560x1280/landscape-1446497562-mcdonnell-douglas-space-station-concept-gpn-2003-00110.jpg?resize=768:*
image 2: https://www.sciencebuddies.org/Files/6751/9/balloon-newtons-3rd.png
