Whatever it is, it ain’t going to construct, observe, or repair itself. In addition to protection and provision, suits must facilitate the reason the wearer has dared to go out into space in the first place.

One of the most basic tasks of extravehicular activity (EVA) is controlling where the wearer is positioned in space. The survey shows several types of mechanisms for this. First, if your EVA never needs you to leave the surface of the spaceship, you can go with mountaineering gear or sticky feet. (Or sticky hands.) We can think of maneuvering through space as similar to piloting a craft, but the outputs and interfaces have to be made wearable, like wearable control panels. We might also expect to see some tunnel in the sky displays to help with navigation. We’d also want to see some AI safeguard features, to return the spacewalker to safety when things go awry. (Narrator: We don’t.)

Mountaineering gear

In Stowaway (2021) astronauts undertake unplanned EVAs with carabiners and gear akin to mountaineers use. This makes some sense, though even this equipment needs to be modified for use by astronauts’ thick gloves.

Sticky feet (and hands)

Though it’s not extravehicular, I have to give a shout out to 2001: A Space Odyssey (1969), where we see a flight attendant manage their position in the microgravity with special shoes that adhere to the floor. It’s a lovely example of a competent Hand Wave. We don’t need to know how it works because it says, right there, “Grip shoes.” Done. Though props to the actress Heather Downham, who had to make up a funny walk to illustrate that it still isn’t like walking on earth.

With magnetic boots, seen in Destination Moon, the wearer simply walks around and manages the slight awkwardness of having to pull a foot up with extra force, and have it snap back down on its own.

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Battlestar Galactica added magnetic handgrips to augment the control provided by magnetized boots. With them, Sergeant Mathias is able to crawl around the outside of an enemy vessel, inspecting it. While crawling, she holds grip bars mounted to circles that contain the magnets. A mechanism for turning the magnet off is not seen, but like these portable electric grabbers, it could be as simple as a thumb button.

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Iron Man also had his Mark 50 suit form stabilizing suction cups before cutting a hole in the hull of the Q-Ship.

In the electromagnetic version of boots, seen in Star Trek: First Contact, the wearer turns the magnets on with a control strapped to their thigh. Once on, the magnetization seems to be sensitive to the wearer’s walk, automatically lessening when the boot is lifted off. This gives the wearer something of a natural gait. The magnetism can be turned off again to be able to make microgravity maneuvers, such as dramatically leaping away from Borg minions.

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Star Trek: Discovery also included this technology, but with what appears to be a gestural activation and a cool glowing red dots on the sides and back of the heel. The back of each heel has a stack of red lights that count down to when they turn off, as, I guess, a warning to anyone around them that they’re about to be “air” borne.

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Quick “gotcha” aside: neither Destination Moon nor Star Trek: First Contact bothers to explain how characters are meant to be able to kneel while wearing magnetized boots. Yet this very thing happens in both films.

Controlled Propellant

If your extravehicular task has you leaving the surface of the ship and moving around space, you likely need a controlled propellant. This is seen only a few times in the survey.

In the film Mission to Mars, the manned mobility unit, or MMU, seen in the film is based loosely on NASA’s MMU. A nice thing about the device is that unlike the other controlled propellant interfaces, we can actually see some of the interaction and not just the effect. The interfaces are subtly different in that the Mission to Mars spacewalkers travel forward and backward by angling the handgrips forward and backward rather than with a joystick on an armrest. This seems like a closer mapping, but also seems more prone to error by accidental touching or bumping into something.

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The plus side is an interface that is much more cinegenic, where the audience is more clearly able to see the cause and effect of the spacewalker’s interactions with the device.

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If you have propellent in a Moh’s 4 or 5 film, you might need to acknowledge that propellant is a limited resource. Over the course of the same (heartbreaking) scene shown above, we see an interface where one spacewalker monitors his fuel, and another where a spacewalker realizes that she has traveled as far as she can with her MMU and still return to safety.

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For those wondering, Michael Burnham’s flight to the mysterious signal in that pilot uses propellant, but is managed and monitored by controllers on Discovery, so it makes sense that we don’t see any maneuvering interfaces for her. We could dive in and review the interfaces the bridge crew uses (and try to map that onto a spacesuit), but we only get snippets of these screens and see no controls.

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Iron Man’s suits employ some Phlebotinum propellant that lasts for ever, can fit inside his tailored suit, and are powerful enough to achieve escape velocity.

All-in-all, though sci-fi seems to understand the need for characters to move around in spacesuits, very little attention is given to the interfaces that enable it. The Mission to Mars MMU is the only one with explicit attention paid to it, and that’s quite derived from NASA models. It’s an opportunity for film makers should the needs of the plot allow, to give this topic some attention.