The founders of Made in Space say 3-D printing is the key to colonizing space. That's why they are developing the Archinaut, a floating factory to manufacture heavy equipment, even full satellites, in orbit.

The Archinaut is comprised of an industrial sized 3-D printer, cartridges full of plastics and alloys, and robotic arms programmed to assemble the big items extruded by the printer without any human supervision. All of the Archinaut's components are rugged enough to survive in microgravity and harsh conditions like lunar dust storms and extreme temperatures.

CNBC visited the Made in Space headquarters at Moffett Field in Mountain View, California (NASA Research Park) to get a look at the Archinaut as engineers prepared it for a thermal vacuum test and to speak with Archinaut's creators.