The International Space Station has continuously been home to astronauts for more than nineteen years. Astronauts conduct scientific research using dozens of special facilities aboard the space station, which also provides them with a place to eat, sleep, relax and exercise. To make all of this possible requires sending more than 7,000 pounds of spare parts to the station annually. Another 29,000 pounds of spaceflight hardware spares are stored aboard the station and another 39,000 on the ground, ready to fly if needed.
This logistics support system works well for a spacecraft that is orbiting 250 miles above Earth and readily accessible to cargo resupply missions. It is not practical for future missions to the Moon and Mars, however. Astronauts on these long voyages need to be able to make their own spare parts, tools and materials essentially on demand – both for routine needs and to adapt quickly to unforeseen ones. In-space manufacturing (ISM) using 3D printing technology could be an answer.