"I Wouldn't Go Into Space In Something Made On A Sewing Machine!"
Those are the words of the man who designed NASA’s AX line of rigid fiberglass spacesuits in the 1960s.* In fact, the Apollo suits worn on NASA’s moon missions were made on sewing machines, by a company famous for stitching latex and Dacron into Playtex girdles and bras in the 1950s. Today that same firm is working on the latest generation of spacesuits being designed for exploring Mars—suits that combine hard and soft elements.
The perception that “softgoods” design is not hard engineering lives on, says Janet “Jinny” (Guerrin) Ferl. She has been designing space suit assemblies (SSA) at ILC Dover in Delaware (formerly International Latex Corp.) for almost three decades. Ferl leads the Dover team who, along with SSA engineers from ILC’s Houston location, supplied key components of the Z-2 planetary walking suit to NASA last year.
“The Z-2 is the most advanced suit that anyone’s delivered since the EMU (Extravehicular Mobility Unit) used on the Space Shuttle and now on the International Space Station (ISS). It has a lot of pedigree and testing behind it,” she says.
“Aw, you’re just sewin’ a rag,” Ferl drawls, affecting contempt for softgoods work. “People think that because it’s fabric, it’s less of an engineering feat than pumps and batteries and wires and fans.”
Although she likes to unwind with quilting and needlepoint, clothing astronauts for the demands of today’s space missions is a rigorous business. “We inspect every stitch that we put in. And we put a lot of thought into that thread, and how to specify it, and how to test it to make sure it’s going to work every time. We look at how to seam materials, how many stitches per inch, what machine to use, what webbing we attach, how much load it can carry, and how many times components can be cycled before they stretch out and don’t work anymore.” In fact, the SSA is part of a larger system, and must be designed to function flawlessly with the life support system.
Ferl joined the crew at ILC in 1988, as space work was picking up again after the hiatus that followed the Challenger disaster. With the job offer came a question: “So, do you want to work on gloves, or do you want to do everything else?” She chose “everything else,” but her work has come to include complex glove projects—as well as budgets, hiring, and approvals.
On-the-job training began on the plant’s production floor, where Ferl learned each process that goes into constructing a multilayer space suit, and progressed through final acceptance testing. “At that time we had a high production rate, and different floors for sewing, heatsealing, dipping, and molding,” she says. “When I started, there was one computer for the whole engineering group, and it was basically used just for word processing.”
Back then, paper patterns were made by hand, with a pencil, rulers, and a set of curves. Some of those famous seamstresses from the Apollo era were still there, sewing away on specially adapted machines. “I heard all the stories from the Apollo engineers, and I got the benefit of all that experience,” says Ferl. “It was a heady time to learn.” Today the patterns are digital and most cutting—both laser and wheel—is automated. Ferl notes that a few materials still have to be cut and sewn by hand, such as the delicate nylon chiffon that lies against the astronaut’s skin to form the innermost layer of the liquid cooling garment.
For Ferl, “everything else” runs the gamut from selecting materials that protect against heat, radiation, and MMOD (micrometeoroid orbital debris), to configuring a system of interchangeable parts to accommodate the many body sizes that work on the ISS. (It’s not feasible for NASA to send up a custom suit fitted for each astronaut.) Beyond the obvious considerations of safety and functionality lies a host of important, but less glamorous issues, such as cargo weight, cost, and durability.
“NASA keeps asking us, ‘Can’t we just keep that up there another year?’” Ferl says. “And we have to say, ‘This thing is 19 years old. Would you wear your coat after 19 years?’ We’re doing some pretty advanced engineering in terms of materials and structures.” When a vendor ceases manufacturing a chosen fabric, it can be tough to come up with—and validate—a substitute. Some of Ferl’s critical publications have un-sexy titles, like “Minimizing the Effects of Material Obsolescence on Constellation Space Suit System Design” and “Considerations for Flight Certification of Spacesuit Assemblies.”
Getting dressed in space is complicated, so a lot of thought goes into “don/doff” systems. With ILC’s earlier two-piece designs, Ferl explains, “First you shimmy up into the upper torso—then you put on your pants.” The Z-2 is an innovative rear-entry design with an integral life-support “backpack” that latches to the vehicle’s exit hatch. The components are made of multiple softgood layers and have to fit together with bearings and disconnects. When pressurized, the softgoods become hard. The bearings and patterned softgoods are what provide pressurized mobility.
It takes talent to make spacesuits in sizes that work for everyone. “It’s always easier to make things bigger, but small is hard,” Ferl notes. Her work has enabled many female astronauts to take part in EVAs (extra vehicular activities). “NASA is very sensitive about this,” she says. “Nobody set out to exclude women, it’s just that when you try to get smaller, you run out of real estate. The life support system is huge. And gloves can be very challenging, because they need to incorporate a certain amount of hardware and fabric while still providing dexterity in the fingers and wrist.”
Ferl especially enjoys the custom glove projects, which bring her face-to-face with working astronauts. Engineers from ILC’s
Houston and Delaware teams work to fit rare individuals whose hand configurations don’t match an existing glove size (there are about 60 sizes). The process begins with interviews to identify the issues. Casts are made and scanned with 3-D software to build a digital model, layer by layer. The model is then “unwrapped” to create a flat pattern that can be cut from cloth.
Ferl recently worked with astronaut Peggy Whitson on customized gloves for her upcoming mission as part of Expedition 50/51 on the ISS. “As soon as she got the gloves, she loved them,” says Ferl, who traveled to NASA’s Johnson Space Center in Houston and witnessed underwater testing. She watched Whitson emerge triumphant from the Neutral Buoyancy Lab. “I’ve never seen anybody smile so brightly. It made all the difference in the world to her. She’s going to be able to do an EVA without the challenges of poorly fitting gloves and the risk of hand damage. Our engineers did a great job of listening to her comments and responding with good choices. The work is very artistic; it’s not just engineering.”
Shipping And Handling Not Included
Even when the suits are perfect for the astronauts, they need to survive transport in the commercial carriers that now supply the ISS. “A rocket is not a rocket is not a rocket,” says Ferl. Verifying the right packing aterial to accommodate variations in temperature, vibration, and load can be difficult. In addition, “Every material that’s sent to the station—from the astronauts’ clothing to bathroom tissue—has to be tested for toxicity, flammability, and off-gassing to make sure that when you put these things up there in that small closed environment, it’s not going to smell like new carpeting and make people sick.”
Not all choices that go into a suit are driven by science. Ferl was an advocate of NASA’s move to let the public vote on the appearance of the Z-2 suit. Five years earlier, NASA chose a lime-green trim for ILC’s Z-1 suit, which was quickly dubbed the Buzz Lightyear look. “People either loved it or hated it,” she says. “Some people objected that it was bringing spacesuits down to the level of cartoon characters.” For the Z-2 suit competition, Ferl pushed for a collaboration with design students at Philadelphia University. “They taught us a lot about style,” she jokes. “Engineers are not known for their sense of fashion, right?”
Involving the public is important because, over the decades, Ferl has observed less enthusiasm for space exploration. “My impression is that it’s almost taken for granted. Our astronauts used to be American heroes, and now people don’t even know who they are. Once, I would go into a classroom and ask, ‘Who wants to be an astronaut?’ and hands would shoot up all over the room.” Today kids are more likely to dream of designing videogames or working in green energy, she notes.
Ferl wasn’t shooting for the space industry when she studied BME at WPI, but her education was still on target. “WPI taught me about teamwork, project work, and experimentation. I couldn’t imagine going to a school where you sit in a classroom and go through a whole semester of just reading a book and doing problems. The project work and the quick turnaround were absolutely right for me. It prepared me for the way this industry works, and the way products are designed and developed and tested.
“I’m a hands-on person,” she adds. “I still like to get out to do the testing and get my hands on the products we’re making.” On a few occasions, she’s been able to get inside a suit herself and put it through its paces. “I don’t have the kind of suit time some of our other engineers have. I’ve done some neat walking, crawling, and sidestepping when we were looking at lower torso mobility. It takes some training to get good at it.”
The importance of testing never escapes her. “A crew member is going to get into that suit. People depend on it for their life and for the critical work they do. We’ve got to make sure that it functions flawlessly, over and over.”
Ferl learned to stand behind her work in her first job, doing product approval at the FDA. “If I made a bad decision, a lot of people could suffer. It came with a lot of responsibility.” Today, her expertise in “just sewing rags” surrounds astronauts in suits strong enough to protect the beating heart inside.
“You have to develop a certain confidence,” she says. “That comes through knowing the product, and being able to communicate what you know. And once you get there, you can sleep better at night.”