In my stellar empire, the sapient life of the home world are arachnids. Due to an oxygen-heavy world with certain evolutionary characteristics, spider-like beings developed intelligence and formed society, leading them (eventually) to start looking toward the stars. This led to the development of space suits for the pioneering arachnid astronauts.

What would these look like? How would space suits be differently designed to support arachnids?

Let us posit that the arachnids are roughly 4 feet from "spinneret" to fangs. Their legs are large enough to support them (I don't know what that is). They're light compared to us (maybe 25 pounds at the heaviest - bear with me on the whole square cube law deal). They have roughly equivalent technology levels to ourselves at the time of our first missions into the stars.

  • 1
    $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – L.Dutch
    Commented Nov 21, 2018 at 13:55
  • 1
    $\begingroup$ If I remember correctly, in the great Sector General space-hospital series, James White has Dr Prilicla (a giant insectoid capable of flying) who has a spacesuit which covers its body, but not his chitinous legs/feelers. I don't know enough about spider biology to know if you could similarly enclose just the body & have the legs extruding. $\endgroup$
    – Dragonel
    Commented Nov 21, 2018 at 18:31
  • 6
    $\begingroup$ theatlantic.com/science/archive/2018/12/… Seems WorldBuilding ranks right up there as an authoritative source of news leads. $\endgroup$
    – Criggie
    Commented Dec 16, 2018 at 4:44
  • 5
    $\begingroup$ I know this adds nothing to the question or clarifies anything and generally breaks rules for commenting. But I will forever remember that my stupid little spiders and space suits question got the attention of a national newspaper and for a brief moment was on one of their pages. Because you can't make that up. $\endgroup$ Commented Dec 16, 2018 at 7:29

7 Answers 7


Yeah. For the spiders, this is gunna suck, but it’s not undoable. I do suspect it will be more of an exo-exoskeleton than a suit though.

There’s a couple of reasons why it won’t be particularly pleasant. The first has to do with how unbelievably sensitive spiders are. Their bodies are covered in a variety of specialised hair like structures that give them not one but two extra senses, and they’ve got extra bits in their knees that give them yet another one. The suit is basically going to annihilate any option of using those (especially the hairs for sensing air motion, which in some spiders are sensitive enough to pick up on the pressure caused by a laser pointer). It’d be like someone shining a light into your eyeball, but body wide.

Depending on whether or not these extra senses have survived into your modern spiders and how strong they are you may need training, drugs or both in order to deal with the suits (as some people may need anti-nausea drugs to deal with zero-G)

The second reason it would either suck or need some exceptional engineering is that terrestrial spiders breathe via almost all of their body. They don’t have particularly dedicated airways or efficient circulatory systems and as such are used to being surrounded by air in order to get enough oxygen into their vital organs. In other words: you need to keep a flow of air between the suit and the spider or they will suffer from the equivalent of hypoxia (which can be thoroughly unpleasant).

That might not seem like an issue, but it really is. Anything pressurised in space will want to puff up like a balloon. That stops you from moving limbs, severely restricting motion. The only way to deal with it is to have rigid ‘space armour’ that air can flow under without deforming the suit, and that comes with a whole extra set of challenges around mobility/cooling. Not only that but you’ll have to have pump air around the suit in order to keep it oxygenated. Pumps vibrate.

Remember those weird knees I mentioned earlier? They’re super-sensitive vibration sensors. To the poor spider inside this vibrating, solid tin can it’s gunna be thoroughly unpleasant.

Manipulators are simple at least as spiders don’t have dexterous fingers to worry about. As such ‘bond villian’ claws can be added to the ends of the suit and operated using simple squeeze actuators without being too weird. Or you could replace with a variety of simple tools. And any suit umbilicals also have a natural attachment point near the spinnerettes where they can be grasped by hind legs.

So basically: armoured, mechanically clawed, permanently on edge spiders floating through space.


  • 25
    $\begingroup$ This sounds like the kind of nightmare fuel I want. If you're gonna have giant spiders in space why not make them giant mechanized spiders in space. But a question concerning humans, don't we have to do a lot to prepare for space voyages as well? $\endgroup$ Commented Nov 19, 2018 at 18:42
  • 12
    $\begingroup$ A great answer pointing out issues many people don't consider when they think of how awesome or scary spiders are: spiders are very undeveloped and inefficient (in the terms of regulating oxygen and temperature) in comparison with mammals. I would guess that intelligent spiders would rely much more on remote probes and much less on astronauts, especially in the early stages of their space program. $\endgroup$
    – vsz
    Commented Nov 19, 2018 at 22:19
  • 13
    $\begingroup$ "Depending on whether or not these extra senses have survived into your modern spiders and how strong they are" Based on how "dull" modern humans' senses are in comparison to our ape cousins, I'm gonna say no. We're not even all that far from chimpanzees, and we have hardly any sense of touch, smell, taste, or hearing. Sight is the only comparable sense. Compared to other mammals, we're practically cut off from the world. It's hard to imagine a technologically advanced spider being just as endowed with senses as its more primitive ancestors and contemporaries. IOW a suit would work just fine $\endgroup$
    – Rich
    Commented Nov 19, 2018 at 23:02
  • 8
    $\begingroup$ Re, "...breathe via almost all of their body." There are vertebrates that do that. There just aren't any big ones. The square-cube law says, No air-breathing animal will evolve to be four feet long without also evolving specialized organs for breathing (a.k.a., "lungs") and an active circulatory system. $\endgroup$ Commented Nov 20, 2018 at 22:41
  • 9
    $\begingroup$ It's not undoable? YOU MEAN IT CAN'T BE UNDONE?! Spiders in space and we can't undo it???!!! $\endgroup$
    – Wildcard
    Commented Nov 21, 2018 at 19:49

They don't need a spacesuit just oxygen

Warning - Video of a spider in a vacuum chamber (it walks around and lives to tell the tale).


Judging by the video, they don't even need oxygen for a short space walk.

In response to temperature concerns

It really depends where in space they are. Right next to a star they would be burnt up regardless of a space-suit. Away from any stars they would be frozen solid eventually. Their spacecraft could perhaps beam infra-red at them.


At the Earth's distance from the sun, a space thermometer with roughly half its surface is absorbing sunlight would register 45 degrees Fahrenheit. https://www.space.com/14719-spacekids-temperature-outer-space.html

Also many spiders can survive temperatures below freezing.

"...About 9% of spiders in relatively mild areas remain active throughout winter. These are nearly all Linyphiids who can still make a web at temperatures as low as -1°C. ..."


Bonus fact

When they go on space-walks, because they're not enclosed in a suit, they don't have to worry about a connecting cable - they can use spider silk to hold them in the place they need to be.

  • 7
    $\begingroup$ That is so...not how I expected that to go. That spider didn't even freak out. He was just hanging out. Man, outside of the cold my spiders could just walk out the airlock. $\endgroup$ Commented Nov 19, 2018 at 22:38
  • 9
    $\begingroup$ And the cold isn't that cold, because unlike being pressed against ice, the only cooling effect is radiated heat, rather than conducted heat. A black spider will radiate the least possible heat. $\endgroup$ Commented Nov 19, 2018 at 22:59
  • 24
    $\begingroup$ @DewiMorgan No, a black spider will radiate the most possible heat. Properties that make an object good at absorbing radiation (of any kind) also make it good at emitting it, and radiant heat loss is infrared radiation. $\endgroup$ Commented Nov 20, 2018 at 0:26
  • 17
    $\begingroup$ Those hairs work to keep air trapped against its body. It would suffocate eventually, but due to its size it wouldn't become an issue for something like an hour. Such structures don't scale up well, but probably not worth too much calculation. $\endgroup$ Commented Nov 20, 2018 at 3:10
  • 5
    $\begingroup$ GMO sentient spiders with thick fur to use as a diving bell in outer space. I'm sold. You can still put it in unpressurized suit for an oxygen refill though. Or perhaps as something to enter and leave during the space walk. $\endgroup$ Commented Nov 20, 2018 at 14:51

I'm going to go in a different direction here and say that instead of making a space suit, make a space pod with mechanical spider legs.

Have an enclosed pod that the spider can sit inside with legs folded and have mechanical arms/legs that support the pod and allow it to walk around. For simplicity, the pod could have 4 or 6 legs, but there could also be different pods for different jobs with a variety of legs or attachments.

This has the benefit of looking like a spider suit, but doesn't have any of the complexity of trying to allow them to use their own legs.

  • 10
    $\begingroup$ A spider-mecha! And with an actual giant spider riding it! I'm sold. $\endgroup$
    – Mr Lister
    Commented Nov 20, 2018 at 18:24
  • 9
    $\begingroup$ +1 for thinking inside the pod. $\endgroup$ Commented Nov 20, 2018 at 21:45
  • $\begingroup$ See Neal Stephenson's "Anathem" for a human-suit on the same principle. The most difficult part of the pressurized suit, the hands, was handled by having mechanical fingers outside of a sealed spherical shell. The human stays comfortable and unencumbered on the inside, and pushes/pulls fingers through lever action. It loses dexterity and individual joint control, but is much easier to manufacture and repair. $\endgroup$ Commented Nov 21, 2018 at 22:42
  • 1
    $\begingroup$ Do you think they'd fashion a pod in their own image? I know Ripley drives a loader in Aliens, and it looks like a hydraulic human.. But would the spiders necessarily build a spider shaped loader? $\endgroup$
    – Caius Jard
    Commented Nov 22, 2018 at 16:56
  • $\begingroup$ @CaiusJard I think it would be roughly in their image because it would be intuitive to design and pilot. Of course it could look like anything. Pod based is versatile like that. $\endgroup$
    – JPhi1618
    Commented Nov 23, 2018 at 15:17

Hamster ball

Photo of a white hamster in a transparent green plastic hamster ball

A hamster-ball for spiders allows them to breathe through their body, and move around by rolling like a hamster in a ball. Of course a simple plastic ball wouldn't allow much work to be done, but a high-tech ball could have various mechanical appendages to perform any work a space spider needs to do.

  • $\begingroup$ +1, first thing that came to my mind too! $\endgroup$
    – Zimano
    Commented Nov 22, 2018 at 15:04
  • 1
    $\begingroup$ Wrecking Ball online! $\endgroup$ Commented Nov 23, 2018 at 12:38

Tarantulas have retractable claws, similar to that of a cat, so it won't be a far stretch to think a spider could use these claws to fit a suit on.

Tarantulas have a respiratory system that uses book lungs to process oxygen. Tarantulas process oxygen at extremely low rates.

The hairs, or urticating bristles, are a defensive mechanism, early warning system(think Spidey Senses) and even a survival mechanism(some tarantulas use these bristles to create an air bubble around them, giving them potentially hours under water without the need to resurface for air).

Tarantulas are generally measured in diagonal leg span(from the tip of the front leg to the tip of the opposing rear leg).

Tarantulas generally become less active in the cold. Often not eating or drinking for months, or possibly years at a time.

Looking for videos of "tarantula molting" might give you some ideas how they could get the suit on/off. Molting is the process of shedding the old skin.

With all the above information in mind you will need to consider; Are the suits needed for short space walks or would the Tarantulas be wearing them semi-permanently? This will determine if the suit needs air, heat and durability to elements).

I would design a suit where the only opening would be on the under side of the Tarantuals carapace. Allowing the Tarantula to fit it/remove it in a similar process to how it would molt. The fabric should allow the bristles to 'poke' out. The suit should retain warmth and small amounts of oxygen.


Technically, there are two main challenges with space suits.

1) Keep them loose enough and yet tight enough. Human limbs have bulgy muscles and such, to too tight and it's awfully uncomfortable. Platemail or plastic tubes wouldn't really work. For something that has an exoskeleton, this isn't a big deal, you're just duplicating that, essentially making the exoskeleton thicker.

2) Joints. Again, this is a challenge, but not too hard. Unlike with humans, all joints in a spider are relatively simple. There are two types: ball-and-socket, and hinge. Hinge (all the knees) are the simplest possible joints in engineering terms, but ball-and-socket (where legs join to body) are a ginormous pain in the ass in every imaginable engineering aspect.

Not impossible, just so prone to failure. Rather than a ball and socket, probably best to make two hinge joins in a chain, at rightangles to each other. Almost as good as a regular hinge, with most of the advantage of a ball and socket.

[Edit: it has been pointed out to me that arthropods don't have ball-and-socket, anywhere. They all do the two-hinged-joints thing everywhere, already, as I should have remembered from seeing crabs-legs. This makes exoskeletons insanely easy!]

So what it should end up like, is basically just a second skin. Spiders and other arthropods are already accustomed to wearing second skins, and are used to getting out of them, as we see here:


  • 4
    $\begingroup$ Two hinge joints in a chain is in fact exactly what real spiders actually have for their "hips" (as well as insects and crustaceans). $\endgroup$ Commented Nov 20, 2018 at 4:00
  • 1
    $\begingroup$ @LoganR.Kearsley Do some arthropods have other arrangements? $\endgroup$ Commented Nov 20, 2018 at 5:49
  • 2
    $\begingroup$ @AntonSherwood I am not entirely certain. I would suspect not, but I haven't been able to find any scholarly references that specifically address the subject, or sufficiently high resolution photos of, e.g., centipede leg joints, to be sure. Re: insects and crustaceans, the relevant info is practically trivial to come by: just go order a lobster or crab legs at a seafood restaurant, or catch a big grasshopper in your yard to inspect. It's a little harder to get one's hands on a sufficiently large centipede for the structure to be easily naked-eye visible, and I'm not sure I'd want to.... $\endgroup$ Commented Nov 20, 2018 at 15:33
  • 1
    $\begingroup$ Oof, I so wasn't prepared for that video $\endgroup$ Commented Nov 21, 2018 at 13:49
  • 1
    $\begingroup$ @LightnessRacesinOrbit I admit I was worried myself, that the spider might be in pain or shedding the skin as a reaction to poison: I was very grateful for the shot at the end of it standing upright and fully recovered :) $\endgroup$ Commented Nov 26, 2018 at 21:53

You need to step back for an easier "in". I said in my comment to @Joe Bloggs's answer:

Based on how "dull" modern humans' senses are in comparison to our ape cousins, I'm gonna say no. We're not even all that far from chimpanzees, and [by comparison] we have hardly any sense of touch, smell, taste, or hearing. Sight is the only comparable sense.

Compared to other mammals, we're practically cut off from the world.

It's hard to imagine a technologically advanced spider being just as endowed with senses as its more primitive ancestors and contemporaries.

To answer the question based on that evolutionary assumption, then, you need to answer some questions about what these spiders look like, and how they feel about nakedness. I'm not talking homburg hats and four pair of Docs, but do they have any form of clothing? What are the names of the garments?

Anyway, to practical matters:

  • Their hairy legs can be practically bald; and wearing a suit would only be as irritating as wearing socks in bed is for me, i.e. a little bit, nothing like unbearable or overwhelming. Sure, let's say they might need to put on some form of undergarment for protection.
  • Their elbow/knee ears could be fed audio communications, designed into the suit, or the undergarment.
  • Multiple eyes could be used for different purposes, assuming the minor pairs haven't atrophied by evolution.
  • Breathing wouldn't be an issue. Spiders and other arachnids breathe through a book lung. Human space suits are pressurized. (If you have gas, you're breathing that back in.) I would assume that spider space suits would also be pressurized. The book lung of the space spider could also have seen modest evolutionary improvements to increase the airflow.

Everyday clothing is going to be your clue for how to talk about the different components of space suits, and what limitations they might impose on the wearer.

There is also the problem of the spiders' home atmosphere composition. Earth's has changed over the aeons, so sure, pick something. Maybe "they need more oxygen" which is fine because "they're super-strong". Just make your excuses and run with them. Don't necessarily declare them to the reader, unless they need to know world/space mechanics.

A couple of objections raised by others to my comment elsewhere:

  1. the human sense of smell may be physically as good as that of dogs, but just out of practice

  2. humans can feel surface bumps which are just 13nm high

  • 2
    $\begingroup$ Also, does this sapient spider breathes by the pores in the skin or has something like a lung? I have a hard time accepting an environment that favors respiration by the skin and not respiration by lungs. Even a high-oxygen atmosphere would benefit lung users more the ones that breath thru the skin. And intelligence is very demanding when it comes to oxygen. $\endgroup$
    – Geronimo
    Commented Nov 22, 2018 at 0:30
  • $\begingroup$ @Geronimo I believe the question was raised with the idea that they would be just large spiders; i.e. no evolutionary innovations like lungs. I think most of the people providing content on this page did so from "high school knowledge", i.e., incomplete. Arachnids actually have an organ called a book lung. -- I'll add this fact to my answer. $\endgroup$
    – Rich
    Commented Nov 27, 2018 at 17:13

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .