The Strap That Won't Burn on Mars
NASA has cleared a gold-colored Kevlar-PBI webbing for oxygen-rich lunar and Martian cabin atmospheres — one unglamorous fix at a time.
By The space-quantum Desk
Before an astronaut can climb a ladder on the Moon or reach for a storage bag handle on Mars, someone has to make sure the strap holding everything together won't catch fire. A new technical bulletin from NASA's Engineering and Safety Center answers that question for one material: a gold-colored webbing woven from 60% Kevlar and 40% polybenzimidazole (PBI), made by Sturges Manufacturing Company, Inc., that passed NASA flammability testing at 37% oxygen and 8.2 psia — the enriched-atmosphere conditions planned for future crewed missions. [1]
The stakes are higher than they sound. Future lunar and Martian habitats will run on elevated oxygen concentrations to reduce the prebreathe time astronauts need before extravehicular activities. [1] That trade-off compresses decompression logistics but turns the interior atmosphere into a more flammable one — meaning every textile that crews touch, pull, or clip needs to survive conditions that standard meta-aramid or nylon webbings cannot. [1]
Webbing is, in aerospace parlance, a solved problem — until it isn't. Narrow woven fabrics of this kind appear in crew mobility aids, restraint nets, and storage bag handles throughout spacecraft interiors. [1] Off-the-shelf options that work fine in Earth-normal air fail the NASA-STD-6001B flammability standard once oxygen concentration climbs. [1] The NESC's solution is methodical: test commercial-off-the-shelf textiles one category at a time, beginning with those most likely to survive, and publish the results as open building blocks for aerospace hardware designers.
[1] The natural (gold-colored) webbing recorded a maximum oxygen concentration of 37%, while the black variant came in slightly lower at 35%, both at 8.2 psia. [1] Offgassing data were also collected for the natural version, giving designers a fuller picture of what the material releases in a sealed cabin. [1]
What looks like a narrow materials-certification exercise is actually a quiet form of infrastructure building — the kind that makes ambitious missions possible without appearing in any mission highlight reel.
The bulletin is careful about what the result does and does not guarantee. [1] Variations including but not limited to dimensions, weave type and yarn size, density, treatments, color, fiber blend, edge finish technique, the addition of features like hook and loop fasteners, and wear and tear may all affect flammability characteristics and should be evaluated before use. [1] The strategy is being implemented by the Mars Campaign Office and Johnson Space Center with support from the NESC. [1]
The available webbing widths range from one-quarter inch to eight inches, giving designers flexibility across a wide range of softgoods applications. [1] The company's natural-color version is the only variant for which full offgassing data currently exist, making it the more immediately deployable option for enclosed, crewed environments. [1] Flammability performance after wear and tear, the bulletin notes, was not assessed — a gap that downstream hardware programs will need to close. [1]
Space hardware tends to fail at the seams — literally and figuratively. The slow, granular work of certifying individual textiles before any mission patch is sewn reflects a discipline that separates programs that fly from programs that wait.
NASA's Mars Campaign Office is running a systematic first phase of testing commercial-off-the-shelf textiles with high potential to meet flammability requirements. [1] The Kevlar-PBI webbing is one data point in what will need to be a complete catalog — every handle, every strap, every net — before humans sleep in an oxygen-rich room 140 million miles from the nearest fire station.
An enriched oxygen environment increases the flammability risk and the need for improved fire-resistant materials.NASA Engineering and Safety Center