NASA is preparing to send the first woman and man to Mars. The biggest question that needs to be answered before that happens is: What will they wear?
The thin atmosphere on Mars allows more radiation from the Sun and cosmic rays than they reach the ground. The engineering challenge, before NASA’s the spacesuit designers is to develop a material that can withstand and keep dust out of the bearings. Spacesuits are equipped with bearings at the shoulders, wrists, hip, upper thighs, and ankles which help astronaut walk, kneel, and perform other tasks like go close to rocks or maintain a habitat.
Another big question is to find out how long would these materials last on Mars where the radiation breaks down the chemical composition and weakens the tensile strength of the materials.
These are some of the foremost questions in the mind of Amy Ross – the spacesuit designer at NASA’s Johnson Space Center in Houston who is developing new suits for the Moon and Mars. To find the answer to her riddle Ross is awaiting the results of the Perseverance Mars rover, which will carry the samples of the first spacesuit material ever sent to the Red Planet.
Perseverance is carrying five small pieces of spacesuit material which will be studied by an instrument aboard called SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals). The materials, including a piece of helmet visor, are embedded alongside a fragment of a Martian meteorite in SHERLOC’s calibration target. That’s what scientists use to make sure an instrument’s settings are correct, comparing readings on Mars to base-level readings they got on Earth.
According to Ross, these materials are meant to be on the outer layer of a suit which will be exposed to the most radiation. These three in one material include Nomex, a flame-resistant material found in firefighter outfits; Gore-Tex, which is waterproof but breathable; and Kevlar, which has been used in bulletproof vests.
Apart from this Ross and her team wants to test a sample fully made of Vectran which is currently used for the palms of spacesuit gloves. It’s cut-resistant, hence useful on the International Space Station where Micrometeoroids strike handrails outside the station, creating pits with sharp edges that can cut gloves.
Another material being tested includes Teflon or polytetrafluoroethylene (PTFE), which has been used in spacesuits for a long time as a part of the protective coating on the back of the astronaut’s gloves. Teflon a non-reactive, nonstick and waterproof coating is known for its use in cookware.
Finally, there’s a piece of polycarbonate, which we use for helmet bubbles and visors which help reduce ultraviolet light. A nice thing about it is it doesn’t shatter. It is known to bends instead of breaking on impact, and still has good optical properties.
According to Ross the type of spacesuit design differs based on where they are to be used and what you’re doing to do after wearing them on the space station, Moon, or Mars. The ISS suit is designed specifically for microgravity. If you go on a spacewalk, you’re not really walking; you use your hands everywhere. Your lower torso is just used as a stable platform for your upper body. The suit is also exposed to two environmental sources of degradation: solar radiation and atomic oxygen. Atomic oxygen is different from the oxygen we breathe. It’s very reactive and can degrade spacesuit materials.
Designer spacesuit – what is each layer made of
The Moon doesn’t have the atomic oxygen problem but is worse than Mars in terms of radiation. You’re pretty close to the Sun and have no atmosphere to scatter the ultraviolet radiation as you do on Mars. The environments of Moon and Mars aren’t exactly the same, but the durability challenges – materials exposed over long periods of time at low pressures in a dusty environment – are similar.
On Mars, you’re farther from the Sun, and you have at least a little atmosphere to scatter the UV. But that’s when the duration of exposure starts to get you. You have to plan on being exposed on the surface most of the time. Mars spacesuits will be more like ones we use for the Moon and less like those for the ISS.
Perseverance is a robotic scientist weighing close to 1,043 kilograms. The rover’s astrobiology mission will search for signs of past microbial life. It will characterize the planet’s climate and geology, collect samples for a future return to Earth, and pave the way for human exploration of the Red Planet. No matter what day Perseverance launches it will land at Mars’ Jezero Crater on Feb. 18, 2021.
The mission is part of a larger program that includes missions to the Moon as a way to prepare for human exploration of the Red Planet. Charged with returning astronauts to the Moon by 2024, NASA will establish a sustained human presence on and around the Moon by 2028 through NASA’s Artemis lunar exploration plans.