The spacesuits show the signs of age

Today’s bulky spacesuits weigh (or, for the more pedantic, have a mass of) nearly a third more than those worn by Apollo 11 astronauts who walked the moon in the 1960s and 1970s. To complicate matters further, the free fall of the orbit does not enjoy the mitigating effects on Newton’s first and third law of motion (objects persevere in a state of motion unless undergoing the action of a force, and any action results in an equal and opposite action) offered by the gravitational field and the solid surface of the Moon. Astronauts who walk in space must therefore think much more carefully about the consequences of their actions than those who walk on the moon.

Add to this the fact that most of the systems used in today’s spacesuits were designed in the early 1980s. A period long enough to bring out the defects (for example in 2013 an Italian astronaut in the International Space Station – the ISS – almost drowned when a liter of cooling water accumulated in his helmet). If you add to the fact that NASA hopes to bring astronauts back to the moon by the end of this decade, there is a clear need for an update. NASA has a long list of features it would like to change or add. However, according to the agency’s director of extravehicular activities Chris Hansen, the immediate goal is to develop suits that allow far more body movement than the rigid ones that, to use his words, made Apollo astronauts a walk on the moon “they went around hopping like rabbits and falling all the time”.

Tailored
However, the search for new spacesuit projects launched by NASA has not yielded great results. In August 2021, Paul Martin, the agency’s inspector general, concluded that 14 years and $ 420 million had been spent to no avail. Martin also said that although NASA plans to double that figure in the next few years, it will still not produce spacesuits in time for the 2024 moon landing (and currently postponed to 2025). And so, once again treasuring mistakes that should have really taught something at this point, the agency is commissioning the design of the spacesuits to the private sector. The idea is to get something that can be used both in orbit and on the lunar surface. The winner of the race will be announced in May.

As predicted by Dr. Hansen’s directions, an important criterion for success in this race will be the flexibility of the spacesuit. One of the competitors is Astro, a suit proposed by a trio of companies: Collins aerospace of Charlotte, North Carolina, Ilc Dover of Newark, Delaware and Oceaneering of Houston, Texas. Astro uses a lot of vectran, a more resistant synthetic fiber than kevlar, used for bulletproof clothing. Vectran is made with a liquid crystal polymer that gives both the strength and flexibility you need.

Those wearing such a suit should be able to stretch their arms upward and bend downward, gestures that would be impossible with today’s spacesuits. According to Dan Burbank, a former astronaut who helped assemble the ISS in orbit and is now a technologist at Collins, astronauts could even do some push-ups, at least when anchored by gravity to the Earth’s surface.

A version of the Astro designed for moonwalking would allow marches of ten kilometers, a distance that far exceeds those allowed for Apollo astronauts. This lunar hiking kit would be equipped with special boots and a displacement-tracking display placed on the front protective screen to show the wearer where he has been and, crucially, how to get back.

When it comes to spacewalks in Earth’s orbit, however, not a few people question the very need for spacesuits. Instead, they propose miniature spaceships equipped with thrusters and robotic arms. Genesis engineering solutions, a Maryland company, is going this route with what it calls a “one-person spaceship” (single-person spacecraft, sps). The thrusters use compressed nitrogen, although in an emergency they can tap into the spaceship’s air tanks. The arms were originally designed to defuse bombs, so they are much more skilled than an astronaut’s gloved hand; they can be controlled by astronauts walking in space or by an operator acting remotely. Hopefully, the sps will be used on Orbital Reef, a commercial space station built by companies – including Blue Origin and Sierra space – which is expected to be launched in the late 1920s.

Reduce risks and costs
According to Genesis, the SPS offers several advantages over traditional spacesuits. For starters, no airlocks are needed to allow entry and exit from a space station. The nacelle hooks directly to the station, with which it shares the air until the doors that separate them are closed. This means that a pilot can get in and out of an SPS without major problems. Conversely, in order for an astronaut to exit space, an airlock must be emptied and then refilled to re-enter it. Since emptying is never completely efficient, there will be a loss of part of a station’s air supply.

Another key difference is that a spaceship can operate at atmospheric pressure. However, pressurizing a suit so much increases its stiffness and in particular makes its gloves so stiff that they are unusable for manual tasks. The pressure inside a spacesuit is therefore normally maintained at about one third of an atmosphere. In this way, however, there would not be enough oxygen for an astronaut to breathe if normal air were used, so pure oxygen is used. A consequence of this drop in pressure is the risk for the astronaut of incurring decompression sickness: nitrogen emerges from the bloodstream in painful and dangerous bubbles. Therefore, before putting on the suit, astronauts who go out into space must undergo the so-called pre-oxygenation with pure oxygen to purify the blood of nitrogen. An atmosphere with pure oxygen creates a fire hazard. And this 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.

Space suits present a third security risk. This is explained by Brand Griffin, who directs the SPS project at Genesis. The shielding on an SPS offers protection against debris and fast moving micro meteoroids that could puncture a suit. If this were to happen, the vacuum of space would cause the astronaut’s body fluids to vaporize. And another advantage of a spacecraft is that if a pilot could not move for some reason, remotely controlling its thrusters and re-hooking it to the mothership would be easier than returning an astronaut from space to the airlock.

The downside to a miniature spaceship is the cost. According to Genesis, an SPS will cost roughly $ 70 million, roughly four times the cost of a spacesuit. However, such a high initial outlay could be offset by lower maintenance costs. A single spacewalk takes about 63 hours of work aboard the ISS, not counting the excursion itself. Among other things, you have to adapt a suit to the astronaut who will wear it (since they are not made-to-measure items), then you have to count the time needed to put it on and take it off and finally sterilize the interior after each single use. To get a rough idea of ​​how much all this costs, let’s take into account that the rate for the services of a NASA astronaut on the ISS is 130 thousand dollars per hour. According to Blue Origin, the soul behind the Orbital reef, once these costs are also considered, an SPS will be the cheapest option.

Spacewalks in suits are however so dangerous that NASA tends to discourage operators of planned commercial space stations such as Orbital Reef from undertaking them. As for space tourists, then, vehicle exits have always been excluded, no matter how amazing the experience might be. All this could change with the sps. Brent Sherwood, head of Blue origin’s advanced development programs, is convinced of this, which includes “tourist-proof” and automated excursions included in the proposals for holidays in space.

Even if the sps were to function as intended, however, spacesuits will not stop being necessary. The Gateway, an international space station in orbit around the Moon whose assembly is expected to begin after November 2024, was designed to provide space exits in suits, not sps. The Orbital reef, for its part, will allow (despite the skepticism of NASA) of the walks in space both in suit and with sps. This system has yet to prove itself after all.

Furthermore, the technicians working on the spacesuits have other ideas in the pipeline. Ilc Dover, for example, plans to simplify spacewalks in suit by providing life support through an umbilical cord. According to Dan Klopp, the company’s director of business development, this would limit mobility but result in a significant cost cut. Even the positions for attaching the suits, or suitport, are promising. These would allow an astronaut to slip into the back of a spacesuit attached to the outside of a vehicle. After the spacesuit and vehicle are sealed, the suit could be detached without the need for an airlock, as is the case with the SPS.

Finally, it is necessary to take note of the question that hovers over all these attempts: with the walks in space or on the Moon performed by human beings, we actually obtain something that could not be achieved with the use of robots (remotely controlled or completely autonomous) ? Asking this question, however, means questioning the raison d’être of manned space flights. And that could never happen, right?

(Translation by Giusy Muzzopappa)