Duquesne University students design zip tie cutter for NASA
In space, even a discarded zip tie can be deadly.
Orbiting Earth at speeds potentially reaching 17,000 mph, the floating zip tie could slice open an astronaut's suit during a space walk or damage critical equipment, said Garett Craig, a student at Duquesne University. The rigors of space make everything, even the mundane, a challenge.
“Everything out there is so dangerous,” Craig said. “Everything is out to hurt you. Everything is out to cut your suit.”
Craig, 20, a junior at Duquesne, was part of a team of 10 students who spent the past school year working with NASA to make zip ties — especially cutting them — safer for space. The team designed a zip tie cutter for NASA as part of the Micro-G Next Challenge.
The team wasn't who you would expect to work with NASA on developing a new tool. There wasn't a mechanical engineer among them. Only one of the 10 was a physics major. The rest, including Craig, were biomedical engineering students, part of a new program at Duquesne that graduated its first class of 18 students this spring. Members of the team likely may end up working in hospitals — Craig is also majoring in nursing; Tori Kocsis, another member of the team, wants to be a doctor — but the students learned that NASA may have a place for them as well.
The team was one of seven NASA invited to its Johnson Space Center in Houston to put the zip tie cutter in the hands of divers to see how it worked in a low gravity environment. The team watched as divers used its zip tie cutter in NASA's Neutral Buoyancy Lab, 6.2-million-gallon pool where astronauts train for space and test out tools and equipment in low gravity.
“We got to work hands on with the divers, briefing them on how to use our zip tie cutter,” said Kocsis, 18, a sophomore.
Zip ties are easy to use, cut and stow on Earth. But that isn't the case in space. NASA uses zip ties to secure payloads or hardware to the outside of the International Space Station. The agency would like to use zip ties more often — they are light, cheap and effective — but doesn't because NASA doesn't have an effective tool for cutting and securing them.
The suits astronauts wear during spacewalks are bulky. They weigh 280 pounds on Earth but nothing in space. Mobility is limited, especially when it comes to an astronaut's hands.
“When we tried on the gloves ourselves, we could hardly move our fingers,” Kocsis said.
NASA required the cutter to be no bigger than a loaf of bread, weigh less than eight pounds and be usable with one hand, either the left or the right. The tool couldn't have any sharp edges, and the cutting instrument had to be protected. The tool had to cut and retain the zip tie, stashing it in a connected bag or box.
The Duquesne team started working on the project in August. The students used 3D printers to make some parts and machined others. The tool went through nearly 150 iterations. The team cut hundreds of zip ties. They tested the tool in Duquesne's pool to see how it worked in low gravity. Craig took the tool home and tested it in sinks, buckets of water and even the shower.
“It took hours of tinkering,” Craig said.
In October, the team learned NASA had selected them to come to Houston. Six members traveled to the Johnson Space Center at the end of May.
The experience was humbling, Kocsis said. Some things worked. Others didn't. The team saw areas they could improve upon. NASA seemed interested, Craig said.
To keep cut zip ties from floating into space, the team designed a pair of gears that gripped and then ratcheted the zip tie into an attached trash bag. This feature could show up in NASA's final design and one day be used during spacewalks, on the moon or even on Mars.
“And we worked on that,” Craig said.