CHALLENGE MET
Even astronauts need zip-tie cutters, so Duquesne undergrads built one for NASA
Ever wrap a zip-tie around the loop of your jacket zipper after the metal pull tab fell off in the wash? Or use one as a replacement for your weed whacker’s plastic wire?
Zip-ties are not merely a lastminute fix for earthlings, but are also handy for astronauts. The nylon fasteners are used to fix payloads, like satellites, and other hardware outside the International Space Station.
“Things fall apart,” said Garett Craig, a rising junior at Duquesne University who helped build a ziptie cutter prototype for the National Aeronautics and Space Administration. “Guess what? The same problems we face down here are the same problems they face up there.”
As part of its Microgravity NExT challenge, NASA pushed undergraduate students from across the country to build and test out a tool that addresses a real space exploration problem. Challenges included a module leak repair system, a sharp edge detection device, the zip-tie cutter and more.
A team of six students at Duquesne’s new biomedical engineering lab in Uptown — led by Mr. Craig, 21 of Canonsburg — designed a zip-tie cutting prototype. The group was one of seven that ultimately presented its invention at the Johnson Space Center in Houston, Texas, in May.
Divers tested the zip-tie cutters in several locations and configurations around the space center’s Neutral Buoyancy Lab. The pool simulates the same zero-gravity environment that astronauts face in space.
Amid other restrictions, prototypes could not weigh more than eight pounds, should be operable with “extravehicular activity” gloves on [consider the weight and thickness of astronauts’ gloves] and could only use manual power.
The Duquesne team used a simple ratcheting system to push and move a set of gears on the handheld device. The motion of the gears pulls the zip-tie through and cuts it before discarding extra pieces into an attached box.
Most of the cutter was 3D printed with cheap plastic and reinforced with machined pieces of steel and aluminum. With the right tools, it should cost no more than $200 to build, Mr. Craig said. And although it took the team 150 iterations and nearly seven months to perfect the prototype, he posits it could take just a few hours to build one in a manufacturing facility.
Despite its looks — the cutter looks like a hybrid of a wrench and a can opener with some tape wrapped around it — the stakes are high for this simple piece of equipment.
If even a tiny fragment of zip-tie gets loose in space, Mr. Craig said, it could float away at up to 20,000 mph and cause severe damage to the International Space Station, other hardware or cut through the astronauts, themselves.
Mr. Craig said NASA will eventually use a combination of the finalists’ designs to build its own ziptie cutter. Participants signed an agreement acknowledging this from the get-go, but the intellectual property still belongs to the students and the university.
Not that they’re trying to commercialize the ziptie cutter. For Mr. Craig and his team, the experience was invaluable enough.
“Simple little things like this are still a huge problem [for NASA],” he said. “To have college students spend months at a time working on something, it’s free work for them ... and it gives us exposure to what they do.”