VIDEO: Expedition 42-43 mission preview

The dream of a self-sufficient space-faring civilization moved a step closer to reality as a commercial 3D printer was installed aboard the International Space Station for a tryout in orbit.

Astronauts on the International Space Station are eager to begin unpacking 2.6 tons of supplies and experiments — including a package of belated Christmas gifts — after delivery aboard a SpaceX Dragon cargo capsule Monday.

Two NASA astronauts and an Italian flight engineer are sheltering in the space station’s Russian segment as mission control analyzes a possible leak of toxic ammonia coolant aboard the complex.