Scientists at the Indian Space research Organization(ISRO) and Indian Institute of Science(IISc) have developed a sustainable process to make a brick like substance that can be used in building structures on the moon.
So don’t be shocked if you see” House for sale on moon” advertisements in the coming years.
They used urea (from human urine) and lunar soil along with certain bacteria and guar beans to create a brick like substance. Guar gum from Guar beans is used to holds the lunar soil together and it gives the strength for the bricks to hold load. It a marriage of mechnical science and biology that has resulted in this. The bacteria used in these experiment have the capability of producing minerals through metabolic pathways.
Bacteria such as Sporosarcina pasteurii uses urea and calcium and through ureolytic cycle produces calcium carbonate crystals. it is these calcium carbonate crystals that work along with guar beans and gives strength to the “space bricks”.
Formerly known as Bacillus pasteurii, it is a Gram positive bacteria that holds the ability to precipitate calcite , solidifying sand in the presence of urea and calcium. This process of solidifying sand is known as biological cementation or microbiologically induced calcite precipitation.
Sporosarcina pasteurii is a soil borne, facultative anaerobe and alkaliphile (thrives at a pH of 9-10) in nature. They can produce endospores under stressful conditions thus enhancing their chances of survival.The fact that they can carry out the process of biological cementation , gives these bacteria a loads of potential applications,
1. as bio-cement
2. to stabilize marshes and swamps
3. helps solidify liquifiable soils in areas prone to earthquakes and landslides.
The research is being carried out by Aloke Kumar, assistant professor in the department of mechanical engineering and his colleagues at IISc in team with ISRO scientists Arjun Dey and I Venugopal. They mixed the bacteria with a simulant of lunar soil, along with urea and calcium sources and also gum extracted from guar beans. The gum acted as a scaffold for the calcium precipitation. After a few days of incubation, the end result was a product with strength and machinability.
Another area of concern in this field is the cost of taking these materials to space. The cost of sending a pound of a material to space can be somewhere around 7.5 lakhs. But the scientists have solved that too.This process uses lunar soil and urea (which can be sourced from human urine), thereby reducing the overall cost of expenditure pretty much. The process also has a lower carbon foot print due the use of guar gum and not cement for making the space bricks.
Guar gum or guaran is extracted from guar beans. It is a galactomannan polysacchride (composed of glucoseand mannose sugars) and is used as a thickening and stabilizing agent in foods, feeds, and industrial applications. The guar seeds are dehusked, processed and powdered and are made commercially available in a white powder form.
It is used as thickening agents in ice creams, soups and are also considered a good low calorie , high fiber diet food. A small amount of guar gum powder can increase the viscosity many fold higher than the use of same amount of its counterparts such as cornstarch.
According to the scientists, space bricks can be molded into any shape or form, giving them the advantage of creating intricate interlocking structures for construction on the moon.
Although theoretically, the idea of constructing structure on moon sound good but there are still other factors that needed to be considered
What will be the effect of gravity on these structures?
How stable can these structure be on moon?
Although the fact that space bricks have been created is appreciable , my point is, why would one create buildings on moon when you cant survive. The basic needs for survival doesn’t include buildings. These are oxygen, food and water. Then why would you create space bricks before finding out a way to survive on moon?
Maybe with people owning and booking plots on moon, the future won’t be far with people actually shifting to moon. Then the phrase ‘Over the moon ‘ will find it’s literal meaning .