It’s still a long way from Star Trek style replicators, but NASA’s 3-D Printing In Zero-G Technology program could reduce the need for astronauts to wait for costly resupply missions when they need mission critical equipment.

The SpaceX-4 resupply mission, scheduled for September 14, will carry a small 3-D printer created by Made In Space Inc. to the International Space Station (ISS).

The printer, which is roughly the size of a microwave oven, will be used as a test case for printing in microgravity. Lessons learned from this initial trial will be used to create a next generation printer known as the Additive Manufacturing Facility (AMF).

3D printing uses blueprints to build objects by laying down one layer of heated plastic after another. Other more recent printers are able to use other materials to create everything from metal components to food and even human organs.

If the project is successful it could make astronauts on the ISS and future space missions less reliant on infrequent and expensive resupply missions from Earth. The cost of supplying the ISS is approximately $20,000 per kilogram of cargo and, if unforeseen circumstances arrive, astronauts can still be left without essential supplies.

“NASA is great at planning for component failures and contingencies; however, there’s always the potential for unknown scenarios that you couldn’t possibly think of ahead of time. That’s where a 3-D printer in space can pay off. While the first experiment is designed to test the 3-D printing process in microgravity, it is the first step in sustaining longer missions beyond low-Earth orbit,” said Ken Cooper, the principal investigator at Marshall Space Flight Center in Huntsville, Alabama for 3-D printing, in a statement.

While the technology could mean safer, less expensive missions on the ISS, it will be even more important for long duration deep space missions in the future. When NASA decides to send astronauts to, for example, Mars it becomes considerably more difficult to send resupply missions and to send them replacement parts in an emergency.

So, it may still be a long way from Captain Picard’s “Earl Grey, hot” it is an important first step toward self sufficient space missions.