How astronauts will fix their gear using thin air

Additive manufacturing, more commonly known as 3D printing, will be an absolutely critical technology for any long-term settlement on another world. Its ability to take a generic input, such as plastic strips or metal powder, and turn it into any shape of tool an astronaut will need is an absolute game changer. But the chemistry behind these technologies is complicated, and their applications are extremely varied, ranging from creating bricks for settlements to plastics for everything from cups to toothbrush holders.