Astronauts on the International Space Station have a new socket wrench. But it didn't come via cargo ship. It was emailed from planet Earth -- beamed up into space and then printed by the ISS crew using their new 3-D printer.

In late September, space's first zero-gravity 3-D printer was delivered to the International Space Station by a SpaceX resupply mission. In November, astronauts finally got around to assembling the machine, designed and manufactured by California-based company Made In Space. Astronauts successfully tested the printer in late November, and now the new technology is being used with a purpose.

NASA predicted that ISS might become a machine shop with arrival of the new printer. And sure enough, the first printed product of note is a ratcheting socket wrench. It's the first time hardware has ever been emailed into space.

"If the printer is successful, it will not only serve as the first demonstration of additive manufacturing in microgravity, but it also will bring NASA and Made In Space a big step closer to evolving in-space manufacturing for future missions to destinations such as an asteroid and Mars," NASA wrote in a September blog post.

What began as a simple CAD file on computers back on Earth, created by engineers and computer scientists at Made In Space, is now a usable plastic wrench aboard the International Space Station.

"On the ISS, this type of technology translates to lower costs for experiments, faster design iteration, and a safer, better experience for the crew members, who can use it to replace broken parts or create new tools on demand," Mike Chen, Made In Space founder, wrote on Medium's Backchannel.

"When we do set up the first human colonies on the moon, Mars and beyond," Chen added, "we won't use rockets to bring along everything we need. We'll build what we need there, when we need it."