Building infrastructures outside the Earth is currently very difficult and very expensive. For the situation to change, it will be essential that construction outside the Earth be based on simple materials that are easily accessible to astronauts wherever they are.
Aled Roberts and Nigel Scrutton, from the University of Manchester in the UK, have devised a special concrete that could do the trick. With the material’s future use on Mars in mind, these chemists have used a substitute for Martian soil mixed with potato starch and a pinch of salt to create the material, which is twice as robust as ordinary concrete and perfectly suited for used in construction outside the Earth.
Roberts and Scrutton have shown that ordinary potato starch can act as a binder when mixed with (simulated) dust from Mars to produce a material similar to ordinary concrete. When tested, this material, dubbed StarCrete, had a compressive strength of 72 megapascals (MPa), more than double the 32 MPa of ordinary concrete. StarCrete made from lunar dust was even stronger, at over 91 MPa.
These recent advances improve on the earlier version of the material devised by the same team, which required astronauts’ blood and urine as a binder. Although the resulting material had a compressive strength of about 40 MPa, better than normal concrete, the process had the drawback of regularly requiring bleeding. When working in an environment as hostile as space, this option is undoubtedly much less recommended than the use of potato starch.
Using potato starch off-Earth is justified by existing plans for off-Earth production as astronaut food.
A block of the new cosmic concrete. (Photo: Aled Roberts)
Roberts and Scrutton estimate that a 55-pound sack of dehydrated potatoes contains enough starch to produce nearly half a ton of StarCrete. In addition, they discovered that a common salt, obtained from the Martian surface or from astronauts’ tears, significantly improved the strength of StarCrete.
Roberts and Scrutton discuss the technical details of their new class of concrete in the academic journal Open Engineering, under the title “StarCrete: A starch-based biocomposite for off-world construction.” (Fountain: NCYT de Amazings)