TEXTILES.ORG
More than 50 years after the Apollo missions, NASA plans to return to the moon’s surface in 2027 with the Artemis III mission. This flight sets the stage for long-term exploration of the south pole of the moon and eventually Mars. But with these new missions come new challenges for textile engineering.
A new oxygen environment
Among those challenges is flammability. “We’ve been in space for 50 years, 25 years on space stations in Earth’s atmosphere at 21% oxygen,” says Mary Walker, a habitability systems project manager at NASA, currently leading the Softgoods project for the Human Landing System Program. “Anything flammable here would be up there, but most things here pass our flammability testing.”
Cabins on the moon and Mars will have 34% oxygen, which essentially cuts down preparation time for a spacewalk, Walker explains. “We do this with a prebreathe, or breathing with an oxygen mask and purging nitrogen out of your blood to safe levels so that when the astronauts [exit] the vehicle, they can return immediately if there’s an emergency. If we can live in a higher oxygen concentration in the cabin, the prebreathe time is a lot shorter, so the astronauts can maximize the time outside.” However, the downside is that 34% oxygen levels make materials far more flammable.
Fire risk and material shortfalls
“We can’t use what’s currently available because most of these things pose a fire hazard, including elastic, Velcro® and other snaps,” adds Felix Arwen, a NASA soft goods engineering technologist.
Wendy Gao, an aerospace textile engineer currently responsible for textile material selection and development at NASA, shares, “We’re evaluating if we put super nonflammable materials with the elastic, how would that work? If that’s not working, then we have to change the elastic in addition to putting in the nonflammable fiber.”
To that end, NASA is calling for industry support. “That’s why we’re giving talks at conferences, attending trade shows, putting out SBIRs [Small Business Innovation Research requests] and telling people to look at our Space Development Agency feed,” says Gao.
Industry response and market gaps
Gao believes the lag isn’t the industry’s fault. “We haven’t been back to the moon for decades … and back then, NASA was driving the technology and bringing companies together,” she explains.
Arwen sees hope in developing solutions but notes, “There’s probably not a large existing market for textiles that we could buy off the shelf.” Success, he says, lies in combining the right fibers, looms and coatings with experts working together.
ILC Dover, an Ingersoll Rand Business, Frederica, Del., which has supplied NASA’s spacesuits since 1965, is tackling the flammability challenge. “Balancing flammability with the stringent toxicity requirements onboard space vehicles is difficult,” says Linda Hewes, ILC Dover’s engineering manager of materials. She notes that treatments that reduce flammability often increase off-gassing, and while some of ILC Dover’s extravehicular activity suit materials meet flammability requirements, they can’t tackle moon dust mitigation. “Any future development into dust mitigation would encompass both,” she says.
According to Hewes, supply chain disruptions caused by the COVID-19 pandemic are still creating market gaps. “Suppliers going out of business … can lead to product streamlining and eventually the discontinuation of products. ILC Dover is responding by identifying multiple sources of supply and condensing the materials we use … through material commonality and strategic purchasing.”
Comfort and functionality in long missions
Walker notes that longer missions such as Artemis VI “where [the astronauts] are there for 30 days or we’re in transit to Mars for nine months, that’s where that need to be comfortable living in and working in space and where efficiency becomes more important.”
Some features NASA is reviewing include microbial resistance, odor control and dust tolerance. ILC Dover is tackling some of those needs with durable antimicrobial treatments and upgraded fabrics. “By incorporating more permanent antimicrobial control into the fibers … we can eliminate the need for applying antimicrobial treatments after washing the garments,” Hewes explains.
ILC Dover has also worked on enhancing crew comfort with its liquid cooling ventilation garment (LCVG). “The LCVG has tubing running through it … the liner and restraint fabrics encapsulate the tubing,” says Hewes. “Stretchable wicking fabrics improve comfort and fit, keeping the crew drier and potentially eliminating the need for thermal comfort garments.”
Lunar dust—the persistent foe
NASA is testing environmental protective garments to shield against abrasive dust, radiation and temperature extremes. Arwen notes that woven materials could present unique challenges in frigid temperatures. “At temperatures around 30 Kelvin [-406 F], you have flexibility issues. Parts of a spacesuit that need to bend—like gloves, knees and elbows—can become stiff. Coatings can crack, weave structures may stiffen and pores can open. Most of NASA’s testing has failed at those temperatures,” he says. “Ideally, the suit doesn’t reach those temperatures, but there’s no way we can control that.”
Another concern is that static electricity makes lunar dust cling to everything. “We worry about uptake and permeability,” says Arwen. If dust dulls reflective surfaces, “you lose those properties for long-term missions.”
ILC Dover is working on these issues by partnering with SBIR-funded businesses to develop dust mitigation coatings and designs, says Hewes, adding they have also researched garment design “to provide overall dust protection while maintaining mobility.”
Regarding radiation, ILC Dover is researching materials that absorb it and ways to integrate radiation protection into existing suit designs. Still, Hewes notes, “Radiation protection remains one of the hardest challenges to solve in long-distance/duration space travel.”
Beyond the suit
The need for advanced textiles goes beyond clothing, though, extending to the entire habitat, says Gao, covering everything from wall panels to storage bags. “It’s not just a fabric. … There are nonwovens required, felt needed, webbings and accessories, including zippers and sewing threads—[everything that makes up] a complete soft good, which encompasses coatings, finishes, foams and elastics.”
It’s why partnerships and R&D are critical. NASA, says Arwen, is working with universities and mills in low minimum order quantities (MOQs) “to test combinations before eventually scaling them up and connecting with industry partners.”
Hewes says ILC Dover is improving soft goods materials with increased tensile strength and puncture resistance. “What helps us circumvent MOQs is our strategic supplier relationships and our strong expertise in materials.”
Despite the challenges, Walker believes innovation will follow need. “Spaceflight drives innovation,” she says. “Disposable diapers and cordless tools only exist because we needed them to make spaceflight happen, [and] the commercial space industry generally follows NASA’s lead.”
Kelly Hartog is a freelance journalist in Los Angeles, Calif.
SIDEBAR: One small step for man, one giant pile of laundry?
Among the myriad issues NASA currently is tackling ahead of its long-term missions is logistics reduction, which includes laundry, even when you’re 140 million miles from home on Mars.
“Right now, on the International Space Station, the crew cannot do laundry,” says NASA aerospace textile engineer Wendy Gao. “They wear their clothes for a certain number of days, and then they’re put in the trash. Then they get a restock of clothing, but that won’t work when going to Mars. They have to pack everything they need for a mission that could be three years, and now weight becomes a concern.”
In addition, these long-term missions will require the astronauts to exercise, says NASA habitability systems project manager Mary Walker. “This is going to be a whole new component, so we’re looking for ways to deal with microbial resistance and odor too.”
“It’s important because [the crew] will be working, exercising and sweating all the time,” adds NASA soft goods engineering technologist Felix Arwen.
That’s why, says Gao, “We want to see how we could expand the usage or life of crew garments so they can pack fewer clothes, or is there an alternative way to do laundry in space? These are all very interesting things that NASA is looking at.”