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PPE on earth and beyond

December 7th, 2020 / By: / Feature

NASA astronaut Anne McClain works on the International Space Station’s Port-4 truss structure during a six-hour, 39-minute spacewalk to upgrade the orbital complex’s power storage capacity. Photo: NASA.

Spacesuits and medical protective apparel share the challenges of functionality and wearability. 

by Marie O’Mahony

A recent webinar series, “From PPE to Spacesuits” sought to help participants gain a better understanding of shared challenges and solutions, between the two divergent end products. The webinars were organized by Stephanie Pau from the Hamlyn Centre (part of the Institute of Global Health, Imperial College, London) as part of the FAIR-SPACE project, during September to November 2020. The discussion focused on how clothing helps to mitigate the human challenges in these extreme environments, and how better design can support improvements.

Clothing as a system

The first session addressed the topic, “Clothing as a system – ecology and evolution.” Daniel Klopp from American manufacturer ILC Dover described how the company’s engineers typically spend twelve hours on the phone when astronauts are on an extra-vehicular activity (EVA). “The Hollywood version of the spacesuit is very far from reality!” Klopp said, a view that was reinforced by astronaut Richard Linnehan, who compared the experience of doing a spacewalk to wearing a suit of medieval armour while on roller skates, with a giant fishbowl over your head, with boxing gloves and a pair of lobster tongs, and then being asked to go out and change the spark plugs in your car after dark! 

Size and fit were key themes through each of the four sessions, with Klopp describing how the earliest Apollo spacesuits were designed for each individual astronaut and custom tailored. This contrasts with the current and next generation suits that are all modular. 

The intention is to still provide a custom fit for the astronaut but drawing on an array of standardized parts. This reduces the cost and the lifetime of the suit, as only worn or damaged elements need to be replaced rather than the whole suit. It can also be seen as an acknowledgement of the environmental impact of the spacesuit and space missions.

Expedition 58 Flight Engineer Anne McClain of NASA has her Russian Sokol suit pressure checked in preparation for her launch aboard the Soyuz MS-11 spacecraft in 2018 to begin their mission on the International Space Station. Photo: NASA/Aubrey Gemignani.

Protecting in layers

In another session titled, “Protective clothing – layer up!” Retired European Space Agency (ESA) astronaut Dr. Thomas Reiter offered a comparison of his experience wearing a Russian Orlan EVA suit and a U.S. EMU (Extravehicular Mobility Unit) suit. The pressure inside the suits plays a significant role. 

“The higher the internal pressure, the stiffer the suit feels,” according to Reiter. “So, when you go outside and move your arms, your legs, the higher the inside pressure the more strength and force you need to move your arms and especially your hands.”  

The EMU is a little softer, about seven percent difference compared with the Russian spacesuit, making it a bit easier to work in. Future developments at ILC Dover are looking at the development of spacesuits that can be easily resized. 

As part of this strategy they are moving away from the traditional hard-shell upper torso that fits inside the outermost layer of the spacesuit. Replacing it with a hybrid solution would retain some hard elements to support the EMU backpack containing life support systems, but easy to resize because of softer, more flexible elements.

Adaptive clothing 

NASA astronaut Anne McClain began her contribution by holding up a sheaf of papers that she had printed on the International Space Station. “What they detail is every choreographed maneuver during our seven-hour spacewalks, as well as preparation before and after,” McClain said.

The importance of that list goes beyond a safety check; it is so that the technology of the spacesuit disappears because the astronaut is so familiar with it. This removes distraction once on an EVA, allowing the astronaut to focus on the task in hand. 

Dr Arghavan Salles is a Bariatric surgeon, activist and scholar-in-residence at Stanford School of Medicine who began by highlighting the fact that N95 masks come in just two sizes, adding that, “part of the reason that women healthcare workers are more likely to get sick from Covid and die from Covid than the men is likely to be PPE issues.” 

She believes that in medicine everything is built to a reference guide which in her view is a five-foot-nine-inch European male. Ill-fitting garments can mean that more petite surgeons like her have to, on occasion, stand on step ladders to operate on a patient when using long surgical instruments. She agreed with McClain that the ideal PPE is invisible, which allows a surgeon to get on with her job.

NASA astronaut Anne McClain works inside the International Space Station’s Quest joint airlock. The Expedition 58 Flight Engineer was working on U.S. spacesuit maintenance emptying and refilling water in the suits’ cooling loops. Photo: NASA.

Soft robotics

The session titled “Clothing as life support – soft robotics” made note of the need to protect astronauts from micro-meteorite impact. This has caused ILC Dover to think of the outer layer of the spacesuit as a bullet proof vest. 

Thermal protection takes on a whole new meaning in space where there is a significant difference between the dark and light sides of the earth. On the dark side the astronaut’s own body heat can be redirected back at them. However, on the light side of the earth the temperature can be above the boiling point of water. This needs a compound within the layers that will absorb the heat. Without it, Klopp says, the astronauts would cook—literally. This challenge is controlled by the Liquid Cooling Ventilation Garment (LCVG), donned over a wicking fabric next to the body.

What is clear from these discussions is that even the smartest technology or material will be rendered useless unless the product is fully centered around the user. The experiences escribed by the presenters are a serious reminder of the importance of bringing this knowledge to the design process. 

Dr. Marie O’Mahony is an industry consultant, author, academic and a frequent contributor to Advanced Textiles Source. She the author of several books on advanced and smart textiles published by Thames and Hudson, and Visiting Professor at the Royal College of Art (RCA), London. 

The entire series discussed in this article is recorded and hosted on Pansurg Collective’s YouTube channel.