Will humans ever live on other planets? Two astronauts are stuck in space. But if we had to stay their forever, it might not be that fun.
The smelly truth about life in space
Left behind: Suni Williams and Butch Wilmore (above) said it was hard to watch their malfunctioning craft depart the International Space Station without them after being stranded in space for eight months. Glossary
International Space Station - A joint project between the US, Russia, Japan, Canada and the European Space Agency.
Astronaut - Someone whose job it is to go into space.
Pong - A bad smell or a two-dimensional table tennis arcade game. Created in 1972, it is one of the earliest video games.
Radiation - Energy given off when radioactive material decays. It can be extremely harmful and sometimes fatal, causing vomiting, skin damage, hair loss and cancer.
Routine - Something you do regularly and consistently — for example, you might go for a walk before breakfast every day.
GMT - Short for Greenwich Mean Time
Gravity - An invisible force that pulls objects towards each other. Earth's gravity keeps us on the ground and makes things fall. It is less strong on Mars.
Muscles - Tissues in the body that tighten and relax to help us move.
Habitat - An animal’s habitat is the place that they live in.