I’m Aled Roberts, a scientist at the University of Manchester, and I developed a way to potentially make ‘concrete’ on Mars using astronaut blood and urine. AMA!

I’ve read that weightlessness can cause up to 22% drop in blood volume for astronauts. Have you factored that into your idea?

Good point. Microgravity also causes lots of other health problems (including bone, muscle and eyesight degradation) so we doubt the process would ever be used while the crew are in space. The strength of gravity on Mars is about 38% that of Earth, it’s not yet known (to my knowledge) if the same heath problems will arise under reduced gravity as for weightlessness… in our paper we assumed the same production rate as if the astronauts were on earth.

What do you think you would do differently, in both process and resulting product, if you had factored this in before your experiment ?

I don't think I'd have changed anything significantly. If I had to do the project again with what I know now, I would have focused on plant-based proteins rather than blood-based ones as they are a lot more feasible and don't face the same problems.

Do you think colonizing the moon is a necessary step towards colonizing Mars?

Personally, I think so. I think the challenges of even a single crewed trip to the Martian surface and back (let alone establishing a long-term colony) are still extremely great, and we would benefit greatly by using the moon as a stepping-stone to test and develop technologies.

I'm assuming the next natural step would be "shitting bricks"?

This is super cool though. Science is awesome.

We actually did think about this initially, but our "control of substances hazardous to health" form was rejected so we weren't able to experiment on this, sadly.

A material I call “Sement”. I won’t elaborate.

If this is viable, aren't you concerned it will cause NASA et al to favour male astronauts, which will go against equality legislation? :)

More seriously - nice ideas, but how viable is all this in terms of the quantities you could produce vs the quantities required to make anything useful that requires concrete?

I doubt the Sement concept would ever be viable for several reasons, so we’ll probably never seriously look into it - unless we really wanted an Ig Nobel prize.

The quantities produced are quite limited as you say (calculations given in the supplementary info of the paper), so it’d be unfeasible to use the blood/urine concrete as a stand-alone material. However, it could potentially be used as a mortar for heat-fused regolith bricks or sandbags - that way the quantity produced would go a lot further.

Realistically, I think we’ll probably develop a better technology (possibly using sticky plant-based proteins as binders) before we actually get to Mars, so I doubt we’ll actually have to rely on astronaut blood!

"Realistically, I think we’ll probably develop a better technology (possibly using sticky plant-based proteins as binders) before we actually get to Mars,"

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- could you use any known plant proteins in place of the animal albumins discussed in the paper? Would it be possible to make these materials from the proteins of inedible portions of plants grown for food on mars and give that material a use?

That's one of the things I'm currently working on. Pulses (peas, beans etc.) also produce albumin proteins which could hopefully be used instead of blood albumins. If we could get it to work, the technology could be useful for Earth-based applications too.

These albumin proteins are edible, but it might be possible to use inedible parts of the plants too. We've not looked into it, yet :)

Do you prefer mad scientist or unethical genius?

Given I have mad hair and a laboratory in my basement, I feel I suit the mad scientist archetype.

What was the first thing your peers said to you after you submitted the abstract for this research? Because this is both fascinating and disgusting.

Good question. One of the peer reviewers loved it, but said their childhood dream of becoming an astronaut died a little after reading the paper. Another peer reviewer hated it, dismissing it with a single paragraph and saying the content was disappointing. The third reviewer was lawful neutral, and had several pages of tedious suggestions and corrections (which made the paper a lot better, to be fair, so we were very grateful).

Yay for peer review.

Is the temperature specific or could there be a range for the chemical process?

Also, what are the applications for the concrete? Is the resulting material strong enough to fire up a kiln?

The specific temperature isn't too important as far we can tell. We picked 65 Celsius to thoroughly dry the materials out overnight and ensure the protein was denatured (unfolded). Other researchers have obtained similar results drying at room temperature over several days.

It’s possible that higher temperature processing (about 120 - 250 °C) would change the chemical structure of the protein, similar to the reactions that happen when you cook food - but we didn’t investigate this in our study (other researchers have though).

At kiln temperatures the protein will decompose into carbon and pyrolysis gasses, however the inorganic particles may melt slightly and fuse together (a process known as sintering) so the material itself might still hold together.

Do you have any concerns that this technique could be ghoulishly misused by the heartless billionaires that seem determined to influence future space exploration?

I'm picturing crews that have to sign away rights to their precious bodily fluids, mandatory blood donations and diets that turn astronauts into more efficient blood factories.

I don’t have too many concerns, mainly because I think better technology will be developed in the meantime. For instance, something we’re currently working on is using plant-based proteins instead of human blood - which would cut out the middle-man (literally). I think the blood concept would only realistically ever be used in an emergency situation. I imagine the reputation of the billionaires would take a big hit if they seriously endorsed this method, so they’ll probably avoid it.

Wouldn't mind if they gave me some money to fund future research though :)

could you use bacteria to breakdown human waste on mars/in space and produce these proteins instead of needing to harvest them from human blood?

You could indeed. Although if you were to do this, you may as well produce a stronger, stickier protein like synthetic spider silk or the protein glue that shellfish use to stick to rocks. There are a few papers that have assessed this technology and concluded it’d save a lot of weight (and therefore cost) compared to shipping binders from Earth. One issue though is low technology readiness - although we can produce proteins in this way on Earth, at present it generates a lot of waste and uses a lot of water, and the protein
yields aren’t very high. Future developments could make this technology a serious contender though.

Another advantage of this bioreactor technology is versatility - the bacteria could be engineered to produce food, chemicals or even complex pharmaceuticals which would be a fantastic thing to have on Mars (and Earth!).

One of the hard parts of CO2 capture is locking it in permanently, and one of the biggest CO2 villains is cement.

Have you thought of ways that technogy along these lines could be worked into the terrestrial economy to decarbonize the atmosphere?

So much biomass releases CO2 constantly (and methane!), from agriculture and livestock to grass clippings. Nature is constantly capturing carbon, if we could just lock it all into building materials...

You've hit the nail on the head, I've recently founded a startup doing exactly this. Essentially, I've developed and adapted the process so that plant-based proteins can be used instead of blood-based proteins - and instead of moon/Mars dust I'm using captured carbon in the form of carbonate minerals. I can also use ordinary sand/dirt to make relatively green bio-concrete, because ordinary cement/concrete produces huge amounts of CO2 as you say (8% of global emissions).

How do the benefits of colonizing Mars outweigh the cost?

I think the push towards sending humans to Mars will generate a lot of useful offshoot technologies for Earth. Many useful technologies were offshoots from the Apollo program, including many advanced materials and the miniaturization of computer chips - which were developed out of necessity for the program. Many of the technologies we need to colonize Mars will revolve around sustainability and circularity (since you'll need to recycle practically 100% of everything you use whilst on Mars). These technologies could be useful for Earth.

For example, if we develop a way to make bio-concrete out of plant-based proteins for use on Mars, it could be a useful alternative to Earth-based concrete (which accounts for about 8% of global CO2 emissions).

I don't know if the benefits would outweigh the costs though - there's still a lot of uncertainty around this question and I still haven't formed a solid opinion yet...

I'm wondering about the efficiency of requiring all that surplus food to be processed through the astronauts before you can use it as a building material. Could you get a better yield or faster production by using a bioreactor for the albumin and synthesizing the urea with the N2 you're fixing anyway? Any plans to try cutting out the middleman like that, and if not, why?

Good point. At present, bioreactor technology isn’t very efficient and can’t compete with the rate humans produce the protein (12 - 25 g per day in healthy adults). Contemporary bioreactors also use a lot of water and produce a lot of gloopy waste. The additional bioreactor equipment would also add to launch mass and be susceptible to breaking down. Having said that, I think it’s a really promising future technology, as you could produce engineered proteins that are a lot sticker - or use versatile bioreactors to make other useful things like chemicals and even complex pharmaceuticals.

Our main plans for cutting out the middle-man (literally) is to directly use plant-based proteins as binders. Pulses (peas, beans etc.) produce similar albumin proteins which could be used instead, this would overcome most of the issues with using human blood and could also be a useful technology for Earth-based applications.

Is this similar to how they make heme in soy for impossible burger?

I imagine so. They probably treat the soy proteins to behave more like blood proteins to mimic the taste/texture.

Could you not bring an animal to Mars that is more “blood efficient” to use rather than humans?

Potentially, yes. Animal blood should work just as well as human blood, and could be more “blood efficient” as you say. We discuss this possibility in the paper and list some advantages and disadvantages of bringing animals for their blood instead of using humans. The main disadvantage of bringing animals is that they’d require their own specialized facilities (e.g., it would be difficult to train a cow to use a complicated human space toilet) and they would essentially be “dead weight” in terms of tasks they could perform. For example, we think it’d be more useful to bring an extra human doctor/engineer/pilot/botanist rather than their equivalent in rabbits or other animals. On the other hand, one of the main advantages of using animals instead is the fact they can eat cellulosic biomass (i.e., the parts of plants that humans can’t eat) and efficiently turn it into manure. Fluffy rabbits could also be an important psychological boost to the crew :) It's also less of a taboo to eat them in an emergency

Besides blood, what about sweat and tears?

Sweat and tears contain urea, which is something that made the materials 100 - 300% stronger. Realistically, you'd obtain the urea from urine - but in theory you could also extract it from sweat and tears, hence the pun :)

Does it come in powder form? And what's the grain size distribution on that.

The Lunar and Martian regolith simulants come in the form of fine powders, yes. Information on the particle size distribution was provided by the supplier and is given in the supplementary information - for the lunar regolith simulant it's <0.04 - 400 microns, for the martian simulant it's <0.04 - 600 microns.

Hello Roberts, quite astounded with your research myself, and I'm sure the process is much more complicated than what the media depicted. Small jest though, has anyone ever compared this to Death Stranding??

You are the first person I'm aware of to compare it to Death Stranding, congratulations!

Serious question for you on space colony work - When you have talk about using nitrogen fixing organisms, are you targeting specific nitrogen fixing microbes / certain nigrogen cycle processes? And any interest in creating artificial marine environments for the nutrient cycling they offer (seagrass beds are some of the most biogeochemically active environments around, etc)?

I was thinking nitrogen fixation by plants such as pulses (peas, beans etc.) that would be used for food anyway (or technically, the microbes that live in their roots). I didn't give too much thought about this, but artificial marine environments could be an interesting option for nutrient cycling too (if we can spare the water!).

Awesome. Like regolith and Sulphur for the moon?

Yep, sulfur as a binder is another option that's being investigated by others. One of the main advantages of using sulfur is abundance, but drawbacks include high processing energy (you need a lot of heat to extract it from the rocks) and that elemental sulfur is susceptible to sublimation under reduced pressure and heat.

Maybe you already answered this, but how realistically usable is this in the sense to how much resources you're going to need?

A quick google gives the following measures:

• You can expect an average brick weight to be about 5 pounds (2.27 kg)
• On average a single storey home uses approx. 8000 bricks.

Meaning you're going to need 18160 kg of building materials to build a house...

I couldn't find in your report what the ratio of moon/mars dust vs blood plasma is, but even if I guess it generously and assume it's a 9/1 ratio - 50 gram of blood plasma will give you 500 gram of materials per day - so it's still going to take you 36.320 days, or almost a 100 years to build one house

Maybe I'm wrong or I'm missing something here

You’re right, we do some back-of-the-envelope calculations in the supplementary information and also conclude that the technique would not be feasible for construction as a stand-alone material. However, if used as a mortar and combined with heat-fused regolith bricks or sandbagging, the amount of material produced would go a lot further. If you could make large enough bricks/sandbags (a big if), we calculate that it could be feasible for each crew member to produce enough material over the course of a 72-month Mars mission to construct enough habitat space to support an additional crew member.

Realistically though, I think better technologies will be developed in the meantime (for example, using plant-based proteins instead - cutting out the middleman) meaning this concept would only feasibly be employed in an emergency situation.

Thanks for the questions everyone, I had some really engaging discussions but my brain is now fried so I’m going to sign off for the evening. Hope you found this interesting and hopefully I’ll be back in the future to answer questions about my next mad ideas.

A convoluted offshoot of this technology has been my start-up, DeakinBio, which uses plant-based proteins and other biopolymers to make inorganic-biopolymer hybrid materials (or bio-hybrids). I'm trying to make relatively green alternatives to cement and ceramic materials, with a particular focus on making materials from captured carbon (in the form of carbonate minerals).

If you’d like a sample of AstroCrete (or any other material I've developed with my start-up) I’m selling a limited batch of 20 (of each) through my shop. All proceeds go towards further research and development.

I'm currently self-funded (and working from my basement, mad-scientist style) so any support would be greatly appreciated.

Thanks again,

Aled

Do you see astrocrete as being something that can be used on a large scale, or as more of a small quantities where needed type deal?

I doubt it would be used on a large scale, mainly due to crew health concerns and better technologies being developed in the meantime. It could potentially be useful in an emergency though - like an Apollo 13 type disaster. The long communication time between Mars and Earth (up to 44 minutes) means that the crew will have to come up with their own solutions in emergency situations - and being able to MacGyver up a concrete-like material could come in handy. It could be useful for other smaller applications too, as you say (perhaps 3D-printing a specific tool that needs a high compressive strength).

It seems you are assuming the protein would actually come from blood (plasma), but there is already a recombinant version produced by the Pichia pastoris yeast and commercially available: https://pichia.com/science-center/commercialized-products/

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So it seems you don't really need actual donors but instead should focus on a way to "farm" those yeasts on the Moon or Mars in a sustainable way.

Have you already looked into this possibility?

Yes, we discuss the possibility of producing synthetic proteins instead of using blood-based proteins. I think it's a really promising future technology, and versatile bioreactors could also be used to make other useful things like chemicals and even complex pharmaceuticals, however there are some technological challenges that still need to be overcome. Firstly, the rate protein production from bioreactors isn't very high compared to the amount you can get from human blood (40-45 g per litre, produced at a rate of 12 - 25g per day per adult), bioreactors would also add significantly to launch mass (especially given the fact you'd need spare parts for redundancy), bioreactors also use a lot of water and generate a lot of waste. I think these issues will be overcome in the future though, but the technology isn't there yet.

I think a more realistic near-term option would be to use [engineered] plant-based proteins instead of blood-based proteins, since we would be growing plants for food in any case.

So would you separate the albumin from blood? There could be a way to just get the albumin from astronauts and be able to give them back the rest of their blood, right? Like how plasma donations work, where the rest of the blood is recirculated back to the donor? If you use whole blood, did you control to check that nothing else in blood interferes with the process? Maybe whole blood doesn't work as well as albumin because of other blood components?

And if you use blood or urea, how do you recycle the precious water? Does your incubator capture the vapours?

Also, can you give us a sense of how much cement your would be getting? Like how long would it take to build a small structure where astronauts could live in, or whatever meaningful thing you would like to build with cement on Mars?

In any case, cool research and I hope it is used for amazing things in the future!

You’re absolutely right, the idea is the albumin (present in the blood plasma) would be separated and all the blood cells would be put back in the body - just like how plasma donations work as you say. This way it’s a lot less taxing on the body and they can give more frequently than if it was a full blood donation.

The hardening mechanism is driven by dehydration, so it would be possible to recover the water. Given the scarcity of water on Mars, I’m sure they won’t let it go to waste and engineers would devise some way to recover it. One of the advantages of this technique over other proposed construction methods on Mars is that the water is recoverable, other methods (e.g., making the Martian equivalent of conventional cement) consume water through the process of hardening - which is a significant disadvantage.

We do some back-of-the-envelope feasibility calculations in the supplementary information, the bottom line is that the method is not feasible for use as a stand-alone material in construction (the production rate is just too low). However, it could potentially be used as a mortar to stick together heat-fused regolith bricks or sandbags - that way it’d go a lot further. Assuming you could make big enough bricks/sandbags (a big if), we calculate that it could feasibly be possible for each crew member to construct enough additional habitat space to support an additional future member over the course of a 72 week Mars mission.

In reality though, I think a better technology will be developed in the meantime so we wouldn’t need to depend on this method.