Additive manufacturing is currently being proposed as a way to greatly decrease the cost of establishing a permanent (robotic or human) presence on the Moon or Mars by sending only 3D printers to establish a "settlement" (at least basic shelters). This would prevent having to send raw materials and/or expensive/bulky items out of the Earth gravitational field.
Is the current 3D printing technology good enough to achieve this goal? If not, what needs to be overcome? I would think protecting the printer from dust storms would be the most difficult task...
This could be seen as the first step towards one of the holy grail of space exploration, the Von Neumann probe.