For humans to travel deep into space and remain there for months or even years, powerful rockets alone will not be enough. Astronauts will need reliable supplies of oxygen, water and food, while carbon dioxide and waste will have to be continuously removed or recycled.
On short missions, many of these necessities can be carried from Earth. But as spacecraft travel farther and missions last longer, transporting everything astronauts need becomes increasingly difficult and expensive. That has led NASA scientists for decades to investigate a fundamental question: could humans one day live in space using systems that recycle and regenerate the resources they consume?
