Sci-fi Spacesuits: Moving around

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.

Stowaway (2021) Drs Kim and Levinson prepare to scale to the propellant tank.

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.

2001: A Space Odyssey (1969)
Pan Am: “Thank god we invented the…you know, whatever shoes.

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.

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.

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

Avengers: Infinity War (2018)

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.

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.

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.

Destination Moon (1950): Kneeling on the surface of the spaceship.
Star Trek: First Contact (1996): Worf rises from operating the maglock to defend himself.

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.

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.

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.

Mission to Mars (2000): Woody sees that he’s out of fuel.

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.

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.

Avengers: Infinity War (2018)

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.

Sci-fi Spacesuits: Interface Locations

A major concern of the design of spacesuits is basic usability and ergonomics. Given the heavy material needed in the suit for protection and the fact that the user is wearing a helmet, where does a designer put an interface so that it is usable?

Chest panels

Chest panels are those that require that the wearer only look down to manipulate. These are in easy range of motion for the wearer’s hands. The main problem with this location is that there is a hard trade off between visibility and bulkiness.

Arm panels

Arm panels are those that are—brace yourself—mounted to the forearm. This placement is within easy reach, but does mean that the arm on which the panel sits cannot be otherwise engaged, and it seems like it would be prone to accidental activation. This is a greater technological challenge than a chest panel to keep components small and thin enough to be unobtrusive. It also provides some interface challenges to squeeze information and controls into a very small, horizontal format. The survey shows only three arm panels.

The first is the numerical panel seen in 2001: A Space Odyssey (thanks for the catch, Josh!). It provides discrete and easy input, but no feedback. There are inter-button ridges to kind of prevent accidental activation, but they’re quite subtle and I’m not sure how effective they’d be.

2001: A Space Odyssey (1968)

The second is an oversimplified control panel seen in Star Trek: First Contact, where the output is simply the unlabeled lights underneath the buttons indicating system status.

The third is the mission computers seen on the forearms of the astronauts in Mission to Mars. These full color and nonrectangular displays feature rich, graphic mission information in real time, with textual information on the left and graphic information on the right. Input happens via hard buttons located around the periphery.

Side note: One nifty analog interface is the forearm mirror. This isn’t an invention of sci-fi, as it is actually on real world EVAs. It costs a lot of propellant or energy to turn a body around in space, but spacewalkers occasionally need to see what’s behind them and the interface on the chest. So spacesuits have mirrors on the forearm to enable a quick view with just arm movement. This was showcased twice in the movie Mission to Mars.


The easiest place to see something is directly in front of your eyes, i.e. in a heads-up display, or HUD. HUDs are seen frequently in sci-fi, and increasingly in sc-fi spacesuits as well. One is Sunshine. This HUD provides a real-time view of each other individual to whom the wearer is talking while out on an EVA, and a real-time visualization of dangerous solar winds.

These particular spacesuits are optimized for protection very close to the sun, and the visor is limited to a transparent band set near eye level. These spacewalkers couldn’t look down to see the top of a any interfaces on the suit itself, so the HUD makes a great deal of sense here.

Star Trek: Discovery’s pilot episode included a sequence that found Michael Burnham flying 2000 meters away from the U.S.S. Discovery to investigate a mysterious Macguffin. The HUD helped her with wayfinding, navigating, tracking time before lethal radiation exposure (a biological concern, see the prior post), and even doing a scan of things in her surroundings, most notably a Klingon warrior who appears wearing unfamiliar armor. Reference information sits on the periphery of Michael’s vision, but the augmentations occur mapped to her view. (Noting this raises the same issues of binocular parallax seen in the Iron HUD.)

Iron Man’s Mark L armor was able to fly in space, and the Iron HUD came right along with it. Though not designed/built for space, it’s a general AI HUD assisting its spacewalker, so worth including in the sample.

Avengers: Infinity War (2018)

Aside from HUDs, what we see in the survey is similar to what exists in existing real-world extravehicular mobility units (EMUs), i.e. chest panels and arm panels.

Inputs illustrate paradigms

Physical controls range from the provincial switches and dials on the cigarette-girl foldout control panels of Destination Moon to the simple and restrained numerical button panel of 2001, to strangely unlabeled buttons of Star Trek: First Contact’s arm panels (above), and the ham-handed touch screens of Mission to Mars.

Destination Moon (1950)
2001: A Space Odyssey (1968)

As the pictures above reveal, the input panels reflect the familiar technology of the time of the creation of the movie or television show. The 1950s were still rooted in mechanistic paradigms, the late 1960s interfaces were electronic pushbutton, the 2000s had touch screens and miniaturized displays.

Real world interfaces

For comparison and reference, the controls for NASA’s EMU has a control panel on the front, called the Display and Control Module, where most of the controls for the EMU sit.

The image shows that inputs are very different than what we see as inputs in film and television. The controls are large for easy manipulation even with thick gloves, distinct in type and location for confident identification, analog to allow for a minimum of failure points and in-field debugging and maintenance, and well-protected from accidental actuation with guards and deep recesses. The digital display faces up for the convenience of the spacewalker. The interface text is printed backwards so it can be read with the wrist mirror.

The outputs are fairly minimal. They consist of the pressure suit gauge, audio warnings, and the 12-character alphanumeric LCD panel at the top of the DCM. No HUD.

The gauge is mechanical and standard for its type. The audio warnings are a simple warbling tone when something’s awry. The LCD panel provides information about 16 different values that the spacewalker might need, including estimated time of oxygen remaining, actual volume of oxygen remaining, pressure (redundant to the gauge), battery voltage or amperage, and water temperature. To cycle up and down the list, she presses the Mode Selector Switch forward and backward. She can adjust the contrast using the Display Intensity Control potentiometer on the front of the DCM.

A NASA image tweeted in 2019.

The DCMs referenced in the post are from older NASA documents. In more recent images on NASA’s social media, it looks like there have been significant redesigns to the DCM, but so far I haven’t seen details about the new suit’s controls. (Or about how that tiny thing can house all the displays and controls it needs to.)

Sci-fi Spacesuits: Biological needs

Spacesuits must support the biological functioning of the astronaut. There are probably damned fine psychological reasons to not show astronauts their own biometric data while on stressful extravehicular missions, but there is the issue of comfort. Even if temperature, pressure, humidity, and oxygen levels are kept within safe ranges by automatic features of the suit, there is still a need for comfort and control inside of that range. If the suit is to be warn a long time, there must be some accommodation for food, water, urination, and defecation. Additionally, the medical and psychological status of the wearer should be monitored to warn of stress states and emergencies.

Unfortunately, the survey doesn’t reveal any interfaces being used to control temperature, pressure, or oxygen levels. There are some for low oxygen level warnings and testing conditions outside the suit, but these are more outputs than interfaces where interactions take place.

There are also no nods to toilet necessities, though in fairness Hollywood eschews this topic a lot.

The one example of sustenance seen in the survey appears in Sunshine, we see Captain Kaneda take a sip from his drinking tube while performing a dangerous repair of the solar shields. This is the only food or drink seen in the survey, and it is a simple mechanical interface, held in place by material strength in such a way that he needs only to tilt his head to take a drink.

Similarly, in Sunshine, when Capa and Kaneda perform EVA to repair broken solar shields, Cassie tells Capa to relax because he is using up too much oxygen. We see a brief view of her bank of screens that include his biometrics.

Remote monitoring of people in spacesuits is common enough to be a trope, but has been discussed already in the Medical chapter in Make It So, for more on biometrics in sci-fi.

Crowe’s medical monitor in Aliens (1986).

There are some non-interface biological signals for observers. In the movie Alien, as the landing party investigates the xenomorph eggs, we can see that the suit outgases something like steam—slower than exhalations, but regular. Though not presented as such, the suit certainly confirms for any onlooker that the wearer is breathing and the suit functioning.

Given that sci-fi technology glows, it is no surprise to see that lots and lots of spacesuits have glowing bits on the exterior. Though nothing yet in the survey tells us what these lights might be for, it stands to reason that one purpose might be as a simple and immediate line-of-sight status indicator. When things are glowing steadily, it means the life support functions are working smoothly. A blinking red alert on the surface of a spacesuit could draw attention to the individual with the problem, and make finding them easier.

Emergency deployment

One nifty thing that sci-fi can do (but we can’t yet in the real world) is deploy biology-protecting tech at the touch of a button. We see this in the Marvel Cinematic Universe with Starlord’s helmet.

If such tech was available, you’d imagine that it would have some smart sensors to know when it must automatically deploy (sudden loss of oxygen or dangerous impurities in the air), but we don’t see it. But given this speculative tech, one can imagine it working for a whole spacesuit and not just a helmet. It might speed up scenes like this.

What do we see in the real world?

Are there real-world controls that sci-fi is missing? Let’s turn to NASA’s space suits to compare.

The Primary Life-Support System (PLSS) is the complex spacesuit subsystem that provides the life support to the astronaut, and biomedical telemetry back to control. Its main components are the closed-loop oxygen-ventilation system for cycling and recycling oxygen, the moisture (sweat and breath) removal system, and the feedwater system for cooling.

The only “biology” controls that the spacewalker has for these systems are a few on the Display and Control Module (DCM) on the front of the suit. They are the cooling control valve, the oxygen actuator slider, and the fan switch. Only the first is explicitly to control comfort. Other systems, such as pressure, are designed to maintain ideal conditions automatically. Other controls are used for contingency systems for when the automatic systems fail.

Hey, isn’t the text on this thing backwards? Yes, because astronauts can’t look down from inside their helmets, and must view these controls via a wrist mirror. More on this later.

The suit is insulated thoroughly enough that the astronaut’s own body heats the interior, even in complete shade. Because the astronaut’s body constantly adds heat, the suit must be cooled. To do this, the suit cycles water through a Liquid Cooling and Ventilation Garment, which has a fine network of tubes held closely to the astronaut’s skin. Water flows through these tubes and past a sublimator that cools the water with exposure to space. The astronaut can increase or decrease the speed of this flow and thereby the amount to which his body is cooled, by the cooling control valve, a recessed radial valve with fixed positions between 0 (the hottest) and 10 (the coolest), located on the front of the Display Control Module.

The spacewalker does not have EVA access to her biometric data. Sensors measure oxygen consumption and electrocardiograph data and broadcast it to the Mission Control surgeon, who monitors it on her behalf. So whatever the reason is, if it’s good enough for NASA, it’s good enough for the movies.

Back to sci-fi

So, we do see temperature and pressure controls on suits in the real world, which underscores their absence in sci-fi. But, if there hasn’t been any narrative or plot reason for such things to appear in a story, we should not expect them.