Soil bacterium from Earth can both make and repair bricks made from Moon-materials
Researchers in India have now discovered that the same soil bacterium from Earth they used to manufacture bricks made from Moon-materials can also act to repair cracks in those bricks.
A few years ago, researchers at the Department of Mechanical Engineering (ME), IISc developed a technique that uses a soil bacterium called Sporosarcina pasteurii to build bricks out of lunar and Martian soil simulants. The bacterium converts urea and calcium into calcium carbonate crystals that, along with guar gum, glue the soil particles together to create brick-like materials. This process is an eco-friendly and low-cost alternative to using cement.
… In a new study, they created different types of artificial defects in sintered bricks and poured a slurry made from S. pasteurii, guar gum, and lunar soil simulant into them. Over a few days, the slurry penetrated into the defects and the bacterium produced calcium carbonate, which filled them up. The bacterium also produced biopolymers which acted as adhesives that strongly bound the soil particles together with the residual brick structure, thereby recovering much of the brick’s lost strength. This process can stave off the need to replace damaged bricks with new ones, extending the lifespan of built structures.
These results are encouraging but not necessarily for space exploration. This research can likely be applied with great profit here on Earth to repair damaged materials already in place.
As for using it in space or on the Moon, great uncertainties remain, such is whether the bacteria could even survive or function in a different gravity environment. The team hopes to test this on one of India’s planned Gangayaan manned missions.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Researchers in India have now discovered that the same soil bacterium from Earth they used to manufacture bricks made from Moon-materials can also act to repair cracks in those bricks.
A few years ago, researchers at the Department of Mechanical Engineering (ME), IISc developed a technique that uses a soil bacterium called Sporosarcina pasteurii to build bricks out of lunar and Martian soil simulants. The bacterium converts urea and calcium into calcium carbonate crystals that, along with guar gum, glue the soil particles together to create brick-like materials. This process is an eco-friendly and low-cost alternative to using cement.
… In a new study, they created different types of artificial defects in sintered bricks and poured a slurry made from S. pasteurii, guar gum, and lunar soil simulant into them. Over a few days, the slurry penetrated into the defects and the bacterium produced calcium carbonate, which filled them up. The bacterium also produced biopolymers which acted as adhesives that strongly bound the soil particles together with the residual brick structure, thereby recovering much of the brick’s lost strength. This process can stave off the need to replace damaged bricks with new ones, extending the lifespan of built structures.
These results are encouraging but not necessarily for space exploration. This research can likely be applied with great profit here on Earth to repair damaged materials already in place.
As for using it in space or on the Moon, great uncertainties remain, such is whether the bacteria could even survive or function in a different gravity environment. The team hopes to test this on one of India’s planned Gangayaan manned missions.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I wouldn’t be so quick to write off this tech for space settlement purposes. One could build igloo-shaped structures up to quite large sizes, for example, by pouring this material between two hemispherical polymer membranes anchored to a previously fabricated flat floor and sandwiching a life-sustaining atmosphere for as long as the entire pour took and the poured material required to finish setting/curing. The pressure inside the inner membrane would need to be made steadily higher as the pour continued, but that seems quite doable. Once the structure is complete, remove both form membranes, perhaps seal the interior, and then start moving in.
The flat platform and future floor could be fabricated using purely a sintering technology or could be partially or completely formed using this Indian tech. Perhaps sintering to form the very bottom of the slab, then reusable metal circumferential forms, as often employed on Earth, to define the sides, a topper polymer dome to hold at least modest pressure to keep the bugs alive, and then a pour and some final smoothing would yield a floor ready for a “Mooncrete” dome to be constructed above it as already described.
The largest such structures might need to await the advent of a lunar ISRU metal smelting industry in order to obtain rebar for the floor slabs – and perhaps even the domes – but this can probably be dispensed with for smaller, earlier buildings.
If there doesn’t turn out to be much “water” on the Moon – as I suspect may prove the case – then the quantities needed for such construction will need to be imported – and carefully scavenged and recycled. Guar gum would need to be imported initially too, though perhaps biotech – using engineered bacteria – may find a way to grow it using all, or mostly, lunar-sourced raw materials. I suspect that will prove to be the case.
Among the “hardhats” I foresee as being the most numerous early human lunar inhabitants, it would seem SpaceX would need to recruit some of those concrete pourers and finishers now busily helping build Starbase as well as those in other, more obvious, construction and maintenance trades there. The possibility of working gigs on the Moon and/or Mars might prove a considerable hiring inducement for the more adventurous candidates.
They better watch how they drive forklifts–less gravity but the mass is still there–build any momentum and that load goes flying.
Any relationship to the calcite lines formed in limestone rock?