Gone are the days when astronauts at the International Space Station (ISS) are made to wait for the next cargo spacecraft to deliver the tools and supplies that they need. Now that the ISS already has a 3D printer on board, all the astronauts need to do is ask from engineers and scientists on the ground and voila! The much-needed tool is just a print away.

NASA astronaut Barry Wilmore, who is stationed at the ISS, needed a ratcheting socket wrench. Normally, he would have to wait for months for this item to be flown to low Earth orbit, but things work differently now that a 3D printer, which functions in microgravity, has been sent to the space station. It successfully printed its first object last month.

Known as Zero-G Printer, the machine was designed and built by startup company Made in Space. After learning that Wilmore needed a ratcheting socket wrench, Made in Space founder Mike Chen and colleagues came up with a CAD design for one and had this sent to the ISS "faster than a rocket ever could have," marking the first time that a hardware was "emailed" to space.

Chen said that once the design was done, it was converted into a Zero-G Printer-ready format called G-code. The design was then sent to NASA, which in turn transmitted this to the ISS through the Huntsville Operations Support Center that links researchers and developers on the ground with their payloads in the space station. The 3D printer then received the code for the needed part and manufactured the wrench, which took about four hours.

"The socket wrench we just manufactured is the first object we designed on the ground and sent digitally to space, on the fly," Chen wrote.

The ratchet, along with the 20 other objects that were printed by the Zero-G Printer at the space station, will be returned to Earth so scientists can compare the differences between these objects and their corresponding items that were printed on the ground. The findings may help predict the performance of space-manufactured objects in the future.

Chen noted the potential impact of 3D printing technology on human space exploration, particularly with planned manned flights to planet Mars. He said that with the technology, humans exploring or setting up colonies in alien worlds do not have to bring everything that they need. Scientists can just bring along with them a 3D printer and build the items that they need.