9
$\begingroup$

I want to use mechanical counterpressure spacesuits (something along the lines of BioSuit) for my story. They seem to have many advantages over traditional pressure spacesuits.

The existing prototypes are lightweight and do not restrict movement as much as traditional spacesuits. They also seem to be safer when it comes to tearing (no depressurisation). A new generation of materials can make them self-healing to reduce risks even further. Scientists are also looking into using alloys and special wired structures to work as exo-skeletons. Mechanical compression has an additional benefit of slowing down the bone loss process typical for low-gravity environments.

The list of possible advantages and benefits goes on and on. However, I could not find anything specific on radiation protection. What materials or technologies can be used to protect from radiation given that the wearer has to spend hours working in deep space outside of spaceship?

Typical tasks that astronauts perform:

  • repairs of starcraft and equipment that can be done more efficiently by humans (rather than robots);
  • mining equipment maintenance on asteroids;
  • geological surveys prior to terraforming;
  • recreational spacewalks.

Technological level:

  • fully automated and robotised asteroid mining (still some human supervision is needed);
  • space travel at 1/10 of the speed of light;
  • terraforming technologies (however, only one project has been completed successfully by the time of their departure);
  • highly developed recycling and reclamation technologies;
  • genetic engineering;
  • suspended animation.

NB: Something like contemporary EMU is not an option: too bulky, low mobility, and high risk of decompression due to minor damage from a tiny asteroid. My astronauts need (and want) greater freedom of movement and lower risks.

$\endgroup$
  • $\begingroup$ Don't expect too much from current EMUs: How much protection do space EVA suits offer against radiation for the wearer? $\endgroup$ – Alexander Sep 27 '17 at 0:37
  • $\begingroup$ How advanced is space exploration in your universe? Would you consider a new ore from asteroid or planet mining that would be weaved into the suit to provide full on particle protection? Also, what's your opinion on some sort of force field? $\endgroup$ – Xander Sep 27 '17 at 9:14
  • $\begingroup$ @Xander, I would like to avoid handwaving and magic as much as possible. I’m looking for technologies that have a solid scientific support even if can’t implement them right now. $\endgroup$ – Olga Sep 27 '17 at 11:17
  • $\begingroup$ Why bother? No, really: why are you making this an issue? Is it required that the reader knows what material these space suits are made of? The principle of Chekhov's Gun applies to such things as well: unless the knowledge of what material the suit is made of adds anything relevant to the plot or the setting, do not bother with it because adding irrelevant things only muddles up the material with unnecessary fluff. $\endgroup$ – MichaelK Sep 27 '17 at 14:14
  • $\begingroup$ Unless you have an expressed purpose for the materials of these space suits you are just adding restrictions on yourself as an author which can later detract from the story. Suppose you say "The suit can handle the radiation because it is made of [material] and [material]". Well that is all fine for as long as you are in the original environment. But later your protagonists go to another place where the situation is different. Then your reader may go "Wait a minute... with [material] and that environment, the suit cannot handle the radiation!". You just ruined Suspension of Disbelief. $\endgroup$ – MichaelK Sep 27 '17 at 14:17
8
$\begingroup$

How about an umbrella?

backpack mounted umbrella from http://craziestgadgets.com/2011/06/21/7-ways-to-use-an-umbrella-hands-free/

People have been using umbrellas to block radiation for a long time. Here is Robinson Crusoe and his goatskin umbrella.

Robinson Crusoe with umbrella

Seriously! An umbrella gives a large area of coverage. It is not attached to your body so not in your way in the same way armor would be. It can be reoriented to give directional protection. It can be detached and folded up and put away.

A backpack mounted umbrella could have a detector and servos to orient it to block the largest amount of incoming radiation (probably from the sun, just as is the case on earth). It would automatically pivot to shield the astronaut. An umbrella can expand to be very large, completely shading the working astronaut. I mean large like 5 meters across - such a large umbrella would be impractical on earth because of wind and air resistance opposing motion - a nonissue in space. These umbrellas will move with the astronaut, attached via the pack. The huge shady bulk of them will be out of the way of arms and legs.

As regards the material of the umbrella, lead or gold would be fine. An optional beryllium overlay if energetic neutrons are a problem.

The astronaut would need to move slowly because of the inertial mass of the umbrella.

$\endgroup$
  • $\begingroup$ your suggestion would be awesome for TV! I wonder how a group of people would work together... Share umbrellas? Bump into each other? The mobility issue also worries me. Will they be able to install mining equipment, for example? $\endgroup$ – Olga Sep 27 '17 at 15:34
  • 2
    $\begingroup$ The thing about having the umbrellas attached is they can lever themselves off of the human so do not need propulsion. A way to do this for groups of people is to have the umbrellas be detached and at a little distance. These robot umbrellas would be mobile and semiautonomous, watching the humans and moving to shadow them. Scaled up umbrellabots would be good for any deep space operation because they would also intercept larger and even more destructive fast-moving particles. Somehow I envision the umbrellabots like the much abused robot helper in the Iron Man movies. $\endgroup$ – Willk Sep 27 '17 at 17:14
  • $\begingroup$ A cool sci fi would involve space miners under attack. They hack the umbrellabots so they could be weapons. $\endgroup$ – Willk Sep 27 '17 at 17:18
  • $\begingroup$ Lead or golf would magnify the problem. The big hazard in space is particle radiation, which is fancy talk for atoms flying around at a significant fraction of the speed of light. When these hit lead or gold they generate secondary radiation that is rougher on the body than the original particles. Use PVC instead. $\endgroup$ – pojo-guy Sep 28 '17 at 23:22
  • 1
    $\begingroup$ @pojo-guy, pojo-guy, pojo-guy. I reminded you in the OP to put on your beryllium overlay if neutrons were a problem! Don't tell me you left it in the bathroom again. $\endgroup$ – Willk Sep 29 '17 at 19:37
2
$\begingroup$

You don't want lead or other heavy shielding because the biggest danger in space is"particle" radiation, atoms moving at near light speed. When the particles hit heavy shielding they produce a ton of secondary radiation. However, PVC sheeting has shown promise in this application. See https://www.google.com/amp/s/amp.space.com/21561-space-exploration-radiation-protection-plastic.html .

$\endgroup$
2
$\begingroup$

What radiation, specifically? Cosmic radiation is omnidirectional and omnipresent, but can be tolerated for extended periods of time. There is no real need to protect against it during space walks so long as the astronaut has a shielded living area and good health care, assuming they won't be spending years in space.

Solar radiation is unidirectional but isn't particularly dangerous except during flares, which can be predicted. In this case, no amount of man-portable shielding is really going to help, the astronauts will have to retreat into a bunker that has extensive shielding, coming out when the flare is over.

Repeated crossing through the Van Allen radiation belts (or equivalent for another magnetic body) is really bad, so don't do that.

A possibility is a personal magnetic field, shielding the wearer from cosmic radiation. Alas, humans can't operate in a magnetic field strong enough to be effective. Setting up a magnetic field around the ship may be possible, but then an astronaut on a space walk may be outside of it, or worse, continually crossing into and out of it, which just exacerbates the problem (though not much for a ship sized magnetic field).

Another viable option is to harden the human. Improve DNA repair mechanisms, limit free electron damage, boost cancer fighting medications and diets (if you ascribe to the ketogenic anti-cancer theory), keep the humans inside a protective shell and use remote drones for space walks, get between locations as fast as possible, etc. Even with all of this, there will still be a slowly progressing radiation countdown for astronauts with every second spent outside of shielded areas. But with careful selection, you can pick folks with really high radiation tolerance, their kids may also have it, and eventually you could breed a group of "spacers" that can operate in space for extended periods of time with minimal radiation side effects, so long as they can avoid the worst solar flares.

$\endgroup$
  • $\begingroup$ Astronauts are in the process of terraforming a moon of a gas giant, neither of which has any significant magnetosphere. While a lot of things are done by robots, humans still need to perform many hours worth of tasks outside of their ship. They will use genetic engineering to strengthen resistance to radiation in their offspring, but they do not possess technologies necessary to change genomes of adults. $\endgroup$ – Olga Sep 27 '17 at 15:51
  • 1
    $\begingroup$ @Olga Is the "no magnetosphere" mandatory? I have some doubts a moon could be under the giant's Van Allen belt, but you could have something like Callisto, far away enough from the giant's radiation belt but and with its own small magnetic field shielding its surface, or at least its equator. Otherwise, could people simply avoid going outside, and work only in caves and tunnels? Piles of rock and ice are pretty good radiation shields. Also, is it possible to have a gas giant without a magnetic field? $\endgroup$ – Eth Sep 28 '17 at 17:54
  • $\begingroup$ To expand on this answer, given that they are at the surface of a moon, they could use giant ground-based magnetic field generators to shield an entire zone. The biggest challenges with using magnetic fields as radiation shields on spacecrafts are power consumption and mass, and you won't have such a problem on the surface. If they need to go outside the protected zone, they could use ground vehicles to carry smaller generators. If they don't go too far, they could even use power lines. Just remember that this will only protect from particle radiation, though. $\endgroup$ – Eth Sep 28 '17 at 17:59
  • $\begingroup$ @Eth, no magnetosphere is a feature. According to my research, a gas giant doesn’t have to have a magnetic field, but I’m not an astronomer or astrophysicist. I will be building an artificial magnetosphere at least for the moon. However, the colonists will have to mine asteroids. I’m not sure it’s practical to build magnetic fields for those. But you gave an idea about portable shields that might be used there. The ideal solution, of course, would be having a radiation-proof spacesuit. $\endgroup$ – Olga Sep 29 '17 at 7:39
1
$\begingroup$

Okay I'm going to go with a complete suit made from a number of layers, 4-7 are the heavy radiation stops you're really interested in I believe. The layers are all quite thin, the total is probably an inch or less of material, from the inside out:

  1. life support, monitoring, heating, cooling, food, water, air, etc... for the occupant, this is necessarily a skin-contact layer and includes insulation, moisture absorption, pressure stocking, heating circuits and a cooling jacket through which hot and cold working fluids can be passed to keep the operate at as close to an optimal temperature as possible. This is also where ambient pressure is maintained for the human in the suit.

  2. mechanical assess/structure, this is the "power-layer" where any muscle augmentation equipment goes, also where the structural layer that everything else is attached to sits. This is also where you want to put essentials like communications equipment and air supplies.

  3. secondary impact protection, the layer is a three sheet sandwich that with break up and absorb large particle impacts from micrometeorites that somehow get through the outer suit.

The following four layers can probably be stacked in any order, or possibly integrated into a single bi-layer material but I think this is the best layout for separate layers.

  1. secondary Gold baffle, Gold sheet that absorbs any remaining ionising radiation like Gamma and X-Rays.

  2. Boron layer, boron is an extremely effective neutron absorber that will pick up subatomic neutral particles.

  3. positively charged layer, a fine electrically charged Gold mesh that serves the dual role of repelling positively charged particles, including but not limited to protons, and Alpha Particles and forming a primary ionising radiation baffle.

  4. negative charge layer, a fine electrically charged Gold mesh that serves the dual role of repelling negatively charged particles, including but not limited to electrons, and forming a primary ionising radiation baffle. This layer is the outermost radiation layer as ionisation will actually reinforce the charge in this layer.

The outer layers of the suit, ultimately these are, and must be, disposable as they're exposed to raw vacuum and cosmic radiation.

  1. impact protection/armour, at a minimum this is a three layer material that breaks up and stops micrometeors before they can penetrate into the mechanically sensitive layers beneath. The outermost of these layers is hard but relatively thin, it's supposed to be penetrated but only by the shrapnel from the broken impactor, the second layer is thicker and softer, designed to bleed as much energy as possible from the debris and in fact capture most of it, the base layer is a hard, slightly flexible, and relatively thick plate that stops any remaining material, much like the armour in a Tacvest. At the top end layer 8 is full combat armour with energy dissipation and impact dispersion properties that protects the wearer and the suit from direct weapons damage as well as the "minor" damage caused by space debris. This layer will absorb a lot of the lower energy radiation like UV and Infrared which is why it has a limited service life.

  2. utility layer, toolkits, maneuvering packs, mag-boots, and other job specific equipment is all "aftermarket" and will actually go outside the primary suit.

These layers are used for the body and back of the helmet, there are two helmet approaches; the first is a full cover opaque helmet with video feeds displaying the outside environment, the other is to use a front visor, personally I favour the first approach, more protection from radiation etc... and you can't get blinded by accidentally looking at the sun without the shade down if you're closer to the sun than say Venus. The modern space helmet face plate is already about the last word in transparent radiation shielding. Gauntlets are excessively exposed so must be disposables, they comprise of plates composed of full layer material on the back of the hands and finger joints, as a rule, the backs of your hands are more exposed than the palms so the extra material is warranted. The palms and finger tips need to be thinner for the sake of dexterity, so we abbreviate, a thinner life support set that contains insulation and moisture absorption only relying on core temperature to regulate the rest, and use a relatively thick, 3+mm at rest, layer of lead-heavy gel to provide some but less impact protection and maximum radiation shielding in a flexible format. The gel will thin when pressured to improve grip. Or you can forego "by-hand" tool manipulation altogether, and use "waldos" instead in which case the suit looks a bit like this and the operators' hands and arms are no more exposed than any other part of them. Suit joints can use the same leaded gel as the gauntlet palms making them relatively vulnerable but extremely flexible.

Most stellar radiation is in the lower energy band and the stellar winds are primarily composed of protons these are relatively easy to deal with as outlined above. Cosmic Radiation, in the form of high speed, high energy particles will blast through any one or two of the proposed layers without slowing down, which is why there are a number of absorbent layers in the suit, these will hopefully combine to slow and capture cosmic rays. Please note that there will be instances where nothing you can wear will be sufficient, flares, solar-storms, gamma-ray bursts all represent lethal conditions for those caught outside, and possibly even those inside as well.

By the way if you're worried about expense those Gold baffles are paper thin, manufacturing will cost far more than the elements being used.

$\endgroup$
  • $\begingroup$ I like this, (the amount of gold sounds a bit infeasible not that I really care) I know you said "impact dispersion" but I think you need to mention something akin to PLATING for clarity like the ceramic plating in bullet proof vests. If you are truly trying to stop micrometeorites no fabric will disperse enough energy. These things can be traveling at speeds greater than 3x the speed of bullets. $\endgroup$ – anon Oct 3 '17 at 13:11
  • $\begingroup$ @anon Very little actual Gold is needed really it's in paper-thin sheets/strands, it's ridiculously good as a radiation blocker/adsorber. Good point about the armour, have edited for clarity. $\endgroup$ – Ash Oct 3 '17 at 13:22
  • $\begingroup$ I know gold foil can be stretched incredibly thin but its got to be thick enough to not be brittle and maintain its malleability (after all cracks would damage the circuitry). I'd imagine you would need at least roughly 6-8oz per suit. $\endgroup$ – anon Oct 3 '17 at 13:33
  • $\begingroup$ @anon Yeah I'll go to 10oz a suit, better safe than sorry, that about 13000 US Dollars at current prices, modern EVA suits cost 12million US Dollars. I'm not saying the Gold is cheap, just not that hugely important when compared to the cost of turning it into a uniform, mechanically sound sheet or a fine conductive mesh. $\endgroup$ – Ash Oct 3 '17 at 13:41
  • $\begingroup$ @Ash, what about gloves and helmet? $\endgroup$ – Olga Oct 3 '17 at 13:48
0
$\begingroup$

First I want to point out that if they are able to automate mining they can more easily automate ship repair. I wouldn't be surprised if this technology is 'realized' very soon =D.

As for the actual question:

Radiation is very hard to protect against, usually dense materials work best like lead or gold. there are also plenty of other materials capable of reducing radiation.

What protects the Earth from this radiation is its thick atmosphere of water vapor but also this critical magnetic shield called the magnetosphere. The magnetosphere is believed to be caused by the motion of liquid metals in our inner core. So one other possible thought is that the ship generates its own magnetosphere to repel inbound radiation or even the suits somehow generate a field large enough and strong enough to do it (personally the ship sounds more realistic as that protects everything with one large device).

$\endgroup$
  • $\begingroup$ An electromagnetic shield is definitely an option for larger objects (and astronauts are building several for their new planet). However, how to create a personal magnetic field without sacrificing mobility too much? $\endgroup$ – Olga Oct 3 '17 at 13:51
  • $\begingroup$ Well it stands to reason that an astronaut will never stray to far from their vehicle or hab. So it could be that they will mostly work within the protection of their shield. Also, this field is currently in its infancy, its plausible they could develop a small enough component capable of generating a strong enough shield to be carry able on like a backpack. We are still researching how shape, flow, composition of spinning heated metal generates magnetic fields. $\endgroup$ – anon Oct 3 '17 at 14:04
  • $\begingroup$ How far is not too far? And what about Van Allen radiation belts typical for magnetospheres? $\endgroup$ – Olga Oct 3 '17 at 14:08
  • $\begingroup$ That would depend on your proposed theoretical capability of your shield generator. You could turn off your generator periodically to disperse your van allen belt, you could generate a field so strong that its located 1km from the ship, you could engineer your van allen belt to provide more protection to your ship (similar to a mocked atmosphere, in terms of protection). I think the very challenges mentioned here add an interesting characteristic to your story. $\endgroup$ – anon Oct 3 '17 at 14:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.