The space suits are showing their age.

FFIXING PANELS on the International Space Station (ISS) is a bit like repairing a car wearing hard oven mitts and standing on a skateboard. That, at least, is the way Kate Rubins, an astronaut in POT, the American space agency, describes it. And he’s spent 300 days orbiting the Earth aboard the station, so he should know.

Today’s bulky spacesuits weigh (or, for pedants, have a mass) almost a third more than those worn by the Apollo astronauts who walked on the Moon in the 1960s and 1970s. To further complicate matters, orbit free fall lacks the damping effects of Newton’s first and third laws of motion (things move forever unless acted on by a force, and every action results in an equal and opposite reaction) which offers the Gravitational field and solid surface of the Moon. Therefore, spacewalkers must think much more carefully about the consequences of their actions than moonwalkers.

Add in the fact that most of the systems in spacesuits worn today were designed in the early 1980s, which gave plenty of time for their flaws to become apparent (in 2013, for example, a Italian astronaut in the ISS he almost drowned when more than a liter of refreshing water accumulated inside his helmet). It further adds that POT expects to return astronauts to the Moon sometime in the 2020s and it’s clear that the time for an update has come. POT it has a long list of features that it would like to modify or add. But Chris Hansen, the agency’s head of extravehicular activities, says the immediate goal is to develop suits that allow far more body movement than the rigid ones that, as he puts it, had the Apollo Moonwalkers “hopping like bunnies and falling off.”

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POTHowever, the search for new suit designs has not gone well. In August 2021, Paul Martin, his inspector general, concluded that 14 years and $420 million had been spent on meager results. Mr Martin also said that, despite POTIntending to double that sum in subsequent years, it would still not produce spacesuits in time for a moon landing then planned for 2024 (and now pushed back to 2025). So, once again learning a lesson it should have learned by now, the agency is outsourcing suit design to the private sector. The idea is to come up with something that can be adapted for use both in orbit and on the lunar surface. The winner will be announced next month.

As Dr. Hansen’s comments foreshadow, an important criterion for success in this competition will be the flexibility of the spacesuit. One of the contenders is Astro, a suit proposed jointly by three firms: Collins Aerospace, of Charlotte, North Carolina; IDC Dover, of Newark, Delaware; and Oceaneering, of Houston, Texas. Astro makes extensive use of Vectran, a synthetic fiber that is stronger than the Kevlar used in bulletproof clothing. It is made of a liquid crystal polymer that gives it both the resistance and the necessary flexibility.

Wearers of such a suit should be able to stretch and bend, gestures that would be impossible with current spacesuits. According to Dan Burbank, a former astronaut who helped put together the ISS in orbit and who is now a technologist at Collins, could even perform flexes, at least when gravitationally attached to the Earth’s surface.

A version of Astro designed for Moonwalks would allow walks of perhaps 10 km, a distance that dwarfs those managed by Apollo astronauts. This moonwalking kit would be equipped with special boots and a “breadcrumb trail” display on its face shield to show the occupant where it had been and thus, crucially, how to get back home.

However, for spacewalks in Earth orbit, 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 going down this road with what it calls the one-person spacecraft (MSF). The thrusters use compressed nitrogen, although, in an emergency, they could also tap into the ship’s air tanks. The arms were originally designed to defuse bombs, making them much more dexterous than an astronaut’s gloved hand; they can be controlled by the spacewalker or by a remote operator. If all goes well the MSF it will be used on Orbital Reef, a commercial space station being built by companies including Blue Origin and Sierra Space, and scheduled to launch in the late 2020s.

The MSFGenesis believes that it offers several advantages over conventional space suits. For one thing, you don’t need an airlock to let a space station in and out. Instead, the ship docks directly with the station, so the two share their air until the hatches between them are closed. That means a pilot can get in and out of a MSF with little fuss. In contrast, for a proper spacewalker to exit and return to the mother ship requires an airlock to be pumped out and then pumped back in. Since pumping is never completely efficient, some of a station’s air supply is inevitably lost.

Another key difference is that a spacecraft can operate at atmospheric pressure. However, pressurizing a suit to this point increases its stiffness, making his gloves in particular so stiff as to be useless for manual tasks. Therefore, the pressure inside a spacesuit is normally maintained at about one-third of an atmosphere. But this would not provide enough oxygen for an astronaut to breathe if standard air were used. Then pure oxygen is used instead.

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

Spacesuits also carry a third safety hazard, according to Brand Griffin, who heads the MSF effort in Genesis. He says that shielding in a MSF provides protection against fast-moving debris and micrometeorites that would pierce a suit. If this were to happen, the vacuum of space would cause the astronaut’s bodily fluids to evaporate. And yet another advantage of a spacecraft is that, if a pilot were somehow incapacitated, its thrusters could be remotely controlled and docked with the mothership more easily than a spacewalker could be dragged back into an airlock.

The disadvantage of miniature spaceships is the price. An MSF it will cost, according to Genesis, nearly $70 million, about four times the price of a spacesuit. But lower operating costs can offset such initial expense. With tasks that include fitting a suit to the astronaut who will wear it (since they are not custom-made items), putting it on and taking it off, and sterilizing its interior after use, a single spacewalk requires around 63 hours of work aboard the spacecraft. ISS, not counting the excursion itself. To get an idea of ​​the expense involved in this, consider that the cancellation fee for a POT astronaut services in the ISS it is $130,000 per hour. Blue Origin, the driving spirit behind Orbital Reef, believes that once those costs are factored in, a MSF it will end up being the cheapest option.

Suited spacewalks are, in any case, so dangerous that POT is dissuading operators of planned commercial space stations like Orbital Reef from participating in them. As for space tourists, extravehicular exits have always been out of the question, no matter how dazzling the experience. The MSF it will change that, says Brent Sherwood, director of advanced development programs at Blue Origin. He envisions “tourist-proof” automated excursions as part of space vacation packages.

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Even if it works as intended, however, the MSF it will not end the need for spacesuits. Gateway, a lunar-orbiting international space station scheduled to begin assembly sometime after November 2024, has been designed so that departures take place in suits, not single-astronaut spacecraft. Orbital Reef, for its part (and despite POTskepticism), support adapted spacewalks, as well as the MSF. That system, after all, has yet to prove itself.

Plus, spacesuit technologists have other ideas up their sleeves. IDC Dover, for example, plans to simplify proper spacewalks by providing life support via an umbilical cord. This would limit mobility but dramatically reduce costs, says Dan Klopp, the company’s head of business development. Suitports are also promising. With these, an astronaut would climb onto the back of a spacesuit attached to the outside of a vehicle. After the spacesuit and vehicle have been sealed, the suit could be separated without the need for an airlock, as with the MSF.

Above all this, it must be acknowledged, is the question of whether human spacewalks and moonwalks actually accomplish something that robots (whether remotely controlled or fully autonomous) cannot. However, to ask that is to defy 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 headline “Adequate, Rebooted”