Space suits are showing their age

Space suits are showing their age

FIXING PANELS on the International Space Station (ISS) is a bit like doing car repairs wearing tough oven mitts and standing on a skateboard. At least that’s how Kate Rubins, astronaut of the NASA, the American space agency, describes this. And she spent 300 days orbiting Earth aboard the station, so she should have known.

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Today’s bulky spacesuits weigh (or, for the pedantic, have a mass that is) nearly a third more than those worn by the Apollo astronauts who walked on the Moon in the 1960s and 1970s. To complicate matters further things, free fall from orbit lacks the damping effects of Newton’s first and third laws of motion (things move forever unless acted upon by a force, and each action results in an equal and opposite reaction) which are offered by the Moon’s gravitational field and solid surface. Spacewalkers must therefore think much more carefully about the consequences of their actions than Moonwalkers need to.

Add in the fact that most spacesuit systems used today were designed in the early 1980s, giving plenty of time for their flaws to become apparent (in 2013, for example, an Italian astronaut in ISS nearly drowned when more than a liter of cooling water accumulated inside his helmet). Also add that NASA hopes to return astronauts to the moon sometime in the 2020s and it’s clear the time has come for an update. NASA has a long list of features that it would like to modify or add. But Chris Hansen, the agency’s head of extravehicular activity, says the immediate goal is to develop suits that allow far more body movement than the rigid ones that, as he puts it, made the Apollo Moonwalkers “jumping like rabbits and falling.”

adapting

NASAThe search for new suit designs, however, did not go well. In August 2021, Paul Martin, its inspector general, concluded that 14 years and $420 million had been spent on meager results. Mr Martin also said that, despite NASAWith the intention of doubling that sum over the next few years, it still wouldn’t produce spacesuits in time for a moon landing that was planned for 2024 (and now postponed to 2025). So, learning once again a lesson it really should have learned, the agency is distributing the suit design to the private sector. The idea is to create something that can be adapted for use both in orbit and on the lunar surface. The winner will be announced next month.

As the observations of Dr. Hansen, an important criterion of success in this competition will be the flexibility of a spacesuit. One of the competitors is Astro, a process proposed jointly by three companies: Collins Aerospace, of Charlotte, North Carolina; ILC Dover, of Newark, Delaware; and Oceaneering, of Houston, Texas. Astro makes extensive use of Vectran, a synthetic fiber stronger than the Kevlar used in bulletproof clothing. This is done using a liquid crystal polymer that gives it strength and the necessary flexibility.

Wearers of such a suit must be able to reach out and duck, gestures that would be impossible in today’s spacesuits. According to Dan Burbank, a former astronaut who helped set up the ISS in orbit and who is now a technologist at Collins, they could even do push-ups, at least when gravitationally bound to the Earth’s surface.

A version of Astro designed for Moonwalks would allow for walks of perhaps 10 km, a distance that surpasses those managed by Apollo astronauts. This moonwalking kit would be equipped with special boots and a “bread trail” screen on its face shield to show the occupant where they have been – and therefore, crucially, how to get home.

For spacewalks in Earth orbit, however, some people question the need for suits. Instead, they propose miniature spacecraft equipped with thrusters and robotic arms. Genesis Engineering Solutions, a Maryland company, is following that path with what it calls a one-person spaceship (SPS). The thrusters use compressed nitrogen – although in an emergency they can also enter the ship’s air tanks. The arms were originally designed to defuse bombs, making them far more deft than an astronaut’s gloved hand; they can be controlled by the spacewalker or by a remote operator. If all goes well the SPS will be used on Orbital Reef, a commercial space station being built by companies such as Blue Origin and Sierra Space, scheduled for launch in late 2020.

The SPS, Genesis believes, offers several advantages over conventional spacesuits. On the one hand, no air chamber is needed to allow entry and exit from a space station. Instead, the vessel docks directly with the station, so the two share their air until the hatches between them are closed. This means that a pilot can get in and out of a SPS with little noise. In contrast, for a proper spacewalker to leave and return to the mothership, an air chamber needs to be pumped out and then pumped into reentry. Since pumping is never completely efficient, it inevitably leaks some of a station’s air supply.

Another key difference is that a spacecraft can operate at atmospheric pressure. Pressurizing a suit in this way, however, increases its rigidity, making your gloves in particular so stiff that they are useless for manual tasks. The pressure inside a spacesuit is therefore normally maintained at about one-third of an atmosphere. But that wouldn’t provide enough oxygen for an astronaut to breathe if standard air was used. Then pure oxygen is used instead.

One consequence of this drop in pressure is the risk of decompression sickness, in which nitrogen gas emerges from the bloodstream in painful and dangerous bubbles. So, before getting dressed, spacewalkers must undergo a so-called pre-breath of pure oxygen to purge nitrogen from their blood. A pure oxygen atmosphere is also a fire hazard. This is not a theoretical risk. Three Apollo astronauts were killed by fire in a 1967 ground test because their capsule contained such an atmosphere.

Spacesuits also carry a third security risk, according to Brand Griffin, who leads the SPS effort in Genesis. He says the shielding of a SPS provides protection from fast-moving debris and micrometeoroids that would puncture a suit. If that happened, the vacuum of space would cause the astronaut’s bodily fluids to vaporize. And yet another advantage of a spacecraft is that if a pilot were in any way incapacitated, its thrusters could be remotely controlled and docked to the mothership more easily than an astronaut could be transported back into an airlock.

The downside of miniature spaceships is the price. THE SPS will, according to Genesis, cost nearly $70 million — about four times the price of a spacesuit. But lower operating costs can offset these upfront expenses. With tasks that include fitting a suit to the astronaut who will wear it (as they are not bespoke items), putting it on and off, and sterilizing its interior after use, a single spacewalk requires around 63 hours of work aboard the ISS, not counting the tour itself. To get an idea of ​​the expense involved in this, consider that the charge rate for a NASA astronaut services in ISS is $130,000 per hour. Blue Origin, the moving spirit behind Orbital Reef, reckons that once these costs are factored in, a SPS will end up being the cheapest option.

Proper spacewalks are, in any case, so dangerous that NASA is discouraging operators of planned commercial space stations such as Orbital Reef from getting involved. As for space tourists, extravehicular tours have always been out of the question, no matter how dazzling the experience. The SPS will change that, says Brent Sherwood, head of advanced development programs at Blue Origin. He envisions automated “tourist-proof” tours as part of space vacation packages.

high fashion

Even if it works as intended, however, the SPS It won’t do away with the need for spacesuits. Gateway, a lunar-orbiting international space station whose assembly is planned to begin sometime after November 2024, is designed so that departures take place in suits, not single-astronaut spacecraft. Orbital Reef will, in turn (and despite NASAskepticism of ), support adequate spacewalks, as well as the SPS. This system, after all, has yet to prove itself.

Plus, spacesuit technologists have other ideas up their sleeve. ILC Dover, for example, plans to simplify proper spacewalking by providing life support via an umbilical cord. That would limit mobility but dramatically reduce costs, says Dan Klopp, the company’s head of business development. “Suitports” are also promising. With them, an astronaut would climb into the back of a spacesuit attached to the outside of a vehicle. After the spacesuit and vehicle have been sealed, the suit can be removed without the need for an inner tube, as with the spacesuit. SPS.

Hovering over all of this, it must be acknowledged, is the question of whether human spacewalks and moonwalks really achieve something that robots (remotely controlled or fully autonomous) cannot. To ask this, however, is to challenge the whole reason for manned spaceflight. And that would never work, would it?

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This article appeared in the Science and Technology section of the print edition under the title “Adapted, restarted”

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