
So as part of the advance supply drops we should send rocket loads of Smash to Mars. Reminds me of something...
Have you ended up on Mars or the Moon and do you want to build a safe home from the dusty material surrounding you? Then potatoes are what you need, according to researchers at Manchester University. Scientists at the famed institution have created a new material, they call "StarCrete", which is not made from actual stars, but …
Here we can see a video of the futuristic AI robots constructing some StarCrete on Mars from those ingredients.
Originally they were proposing using astronauts' blood for the concrete. This led to the boggleworthy quote in TechXplore
While the resulting material had a compressive strength of around 40 MPa, which is better than normal concrete, the process had the drawback of requiring blood on a regular basis. When operating in an environment as hostile as space, this option was seen as less feasible than using potato starch.
Which belatedly impetuous non-entity coined that particular neologism?
We've only made it to one 'star' thus far in our existance as a (relatively) rational species capable of extra-planetary travel, and that's only by proxy.
If you call it 'StarCrete' now - what are you going to call the new stuff when actually make it to a different star and come up with something new?
StarCrete 2.0 ??
That compressive strength 'better than concrete' is all well and good, but concrete lacks in tensile strength (which is why modern buildings use steel inside the concrete), and I suspect this 'starcrete' will have similair properties. Seeing as mining and refining metal directly on the moon / Mars is still many centuries in the future, and we really don't want to have to launch thousands of tuns of steel up a gravity well, the buildings there are going to have to use a domed structure, which allows for the use of material with very low tensile strength and high compressive strength.
The relatively low gravity on the moon / Mars would probably allow larger structures as well, since there's less force on the structure per unit mass. So our space-faring grandkids are likely to be living in giant igloos!!
jmch,
You got in before me, because I decided to go have lunch before commenting... (still, it was a good lunch).
I did note that they claim for the mars rock version slightly higher flexure strength than is typical of concrete, so it might be very slightly better in tension, but yup, this stuff would seem to be good for arches and domes acting in compression, not (unless reinforced) beams and columns which are subject to bending and hence tensile forces.
Potentially, though the reinforcement might not be metal - it might be possible to use a fibre based reinforcement (Kevlar strands or similar), particularly if beams and precast and pre-stressed.
From a skim through the paper, it appears to be more water-efficient than concrete (where the water and cement react chemically - concrete doesn't dry, it hydrates), but seems to need a heat source to get the reaction to occur. Maybe that will be from the Rolls Royce Moonbase Nuclear reactor (https://www.bbc.co.uk/news/uk-england-derbyshire-64982477), which can power the air-fryer for the chips, too.
Also, we've been mucking about with concrete for a couple of thousand years and still run into problems when we used incompatible materials for the aggregates or in the cement ("concrete cancer" etc); I wonder how resilient this will be / how sensitive it is to the chemical composition of the material used for aggregate.
Sorry to put a damper on your potato igloo but domes only work on earth because the air pressure on the outside is th same as inside. Yes you can have inflatable domes but they are made of high tensile fabric, not high compressive strength potatos. Since there is virtually no atmosphere on the moon and very little on Mars, igloos are unlikely to be the answer. I think most habitats will be underground and the starcrete will be used to line tunnels. This will also be required for radiation protection. Space dwelling humans will become troglodytes once again.
Assuming you have sent a nice big nuclear power plant to your Moon/Mars base you can just use the power to press the Moon/Mars dust into bricks of any shape required. All you need is lots of heat and pressure and you have a kind of glass brick but it's engineering parameters would depend on the composition of the regolith/sand used to make it. Besides, almost all of the Lunar/Mars base will be underground if they have any sense at all. It's far easier to dig and seal an environment than it is to build one from scratch when you have no effective atmosphere and LOTS of high-energy particles flying around on the surface due to zero magnetic field. Tunnel sealing will need to be done with a semi-flexible sealant that can cope with vacuum on one side and pressure on the other as well as with heat/tidal expansion/contraction and moon/mars-quakes.
The first things I would send to the Moon/Mars would be refineries. These would suck up the regolith/sand and separate out the useful materials such as Aluminium, Iron, Magnesium, and of course Oxygen. These then get stockpiled for the "builder" machines sent later on to use. Other "refineries" could dig the tunnels that would later become the base itself and refine the material that they dig out. Why lug huge quantities of starch out there just to build with?
“Since starch is the primary constituent of staple foods such as rice, potatoes, and maize, any sustained off-world habitat will likely have the capability to produce starch as food for inhabitants,”
Not just as food. Any permanent settlement will be making drink out of all of those (it's human nature) ... there will be no "leftovers" for pseudo-concrete. Growing any of them in bulk on Mars will not just be exceedingly difficult, I would go as far as to say it'll be nonsensical to even try. In adverse conditions like that, one does not waste food on building.
Instead, use empty fuel tanks for dwellings/labs. Design the entire mission around the concept. Waste not, want not.
Back in the 1970s, straw-slab insulation was all the rage for tower blocks, I kid you not: thick boarding made from packed lengths of straw given a fine coating of cement. Great insulation. Unfortunately, also great cockroach food. What do you do when you are thirty floors up and get an ineradicable infestation of roaches, with black mould promptly colonising the cold spots in the corners? You demolish the tower blocks before their time. Gospel truth, as an architecture student I studied these things while they were being built.
Black mould and its friends-and-relations are also one of the limiting factors in the lives of every space station we have yet built.
Why do I get the feeling that condensation will collect in cold corners of potatoland and black mould will become the moon's first permanent inhabitant?
Look, I know I long wore a "Release Potatoland" badge, but they did release it on Earth in the end, and it wasn't very good anyway. There is no point in a lunar re-release, none at all.
I take this whole mashup (sic) in the spirit of my title ingredient. So should any budding lunarnaut.
I nominate Walkers of Leicestershire (purveyors of fine, fried pototo crisps - aka chips to our yankee friends) to create a nice new factory on (say) the Lunar surface and start processing some STAR-ch based ingredients, so that when Musk/Bezos/NASA-delivered astronauts get to this or any other far flung, distant world, they would be met with some suitable buildings, no doubt flavoured in some unusual combinations...
https://museumofcrisps.com/2020/08/01/39-flavours-walkers-2020-collection/