How astronauts 3D printed a wrench they needed in space
It costs $10,000 per kilogram to blast something into orbit; a liter of water in space costs $10,000.
In fact, only 2% of what NASA sends into space on its rockets is actually used by astronauts for experiments. The rest of the weight is made up by the space vehicle itself and its fuel.
So when it comes to experimentation on the International Space Station, transporting even small items is costly.
This year, however, NASA and partner Made In Space Inc. are planning to solve part of that problem by installing a 3D printing station on the International Space Station (ISS).
The 3D printer station will be able to receive .stl (stereolithography) files with CAD designs transmitted from earth to print a variety of tools astronauts may need, according to Jason Dunn, CTO of Made in Space. The new printing station will be made available to astronauts regardless of their nation status.
Dunn, who spoke at the RAPID Conference here, said that the company's first fused filament fabrication (FFF) 3D printer was sent up last year via a SpaceX Dragon cargo craft. The small desktop 3D printer was used to print 20 objects preloaded on an SD card; a 21st object was printed based on an .stl file transmitted to the printer from Made In Space. The object, a wrench head made from ABS thermoplastic, took about two hours to print, and when it was finished, American astronaut Barry Wilmore removed it from the machine and commented that he wished he had "his ratchet."
Seven days later, after Made In Space designed the printable ratchet and had NASA run it through their qualifications, the file was transmitted to the surprised astronaut, who then put the new ratchet and head to work.
"We're using the space station as a test bed to prove out this technology," Dunn said. "The space station today has limited volume; it's filled with redundancy, it's filled with spare parts."
It's also filled with trash, trash that Dunn said may be recyclable into polymer filament for printing new tools and test equipment. NASA is working with Made In Space now to create a polymer recycling center on the ISS for that very purpose.
Dunn believes 3D printing (also known as additive manufacturing) will be a pathway to humans being able to populate other planets, printing supplies from locally harvested materials or recycling material that's no longer needed.
Additive manufacturing will also enable more fragile objects be created in space than could ever be rocketed up because unlike space equipment today, it won't need to withstand the two Gs of pressure a blastoff places on them. In fact, printed space objects may someday be so fragile, that they'd fall to pieces under Earth's gravity.
Now, if a specific tool is needed on the fly, astronauts must sometimes spend time creating makeshift items to fit the bill. Considering an astronaut's time costs about $40,000 an hour, using that time to build tools out of parts is more than a little wasteful.
"Imagine if you could remove the strain of all that added mass [in a spacecraft]... and time. You just build what you need when you need it," Dunn said.