Almost all living things need oxygen to live. If humans try to live on other planets in the future, lack of oxygen will be one of the main problems.
Some living things, such as plants and algae, produce oxygen. For this reason, scientists are experimenting with growing plants inside spacecrafts and space stations. Plants could produce the oxygen needed by the crew. They could also recycle the water and provide fresh food.
To test this possibility, an experiment called Biosphere 2 was started in the 1990s. This project involved a group of scientists living in a glass structure with a wide variety of plants.
The huge laboratory simulated life in a space station by avoiding any contact with the outside world. The scientists could only consume the food and breathe the oxygen produced inside the structure.
