In a decade’s time, space travel is going to become as common and mundane as air travel! Scientists and industrialists all over the world will soon be setting up lunar bases on the moon for further study, investigation, and exploration. For this, a large amount of supplies are going to be needed.
If we rely too much on transporting supplies from the earth to the moon, it won’t be so easy and feasible. The transportation of goods from the earth to the moon will incur huge costs, and is unsustainable. Therefore an alternative is required.
We can use what is on the moon to sustain and support the people travelling to the moon. The soil of the moon, called “regolith”, is widely available and covers almost the entire lunar surface.
Silica is the most abundant oxide found on the surface of the moon (approximately 45 percent). Thus, sourcing of silicon and its compounds seems pragmatic. But only 400 kg of lunar regolith samples are present on the earth, brought back from the Apollo and Luna missions. This is not enough for all the industries and academia in the world.
The solution to this problem lies in the use of regolith simulants that can mimic the particle morphology, particle size, and particle chemistry of the lunar regolith. Some of the notable simulants developed include JSC-1, BP-1, NU-LHT, and LHS-1. Some of these are available commercially.
Regolith simulants are usually used to extract oxygen, water, and metals. The methods used for this include – carbothermal reduction, molten regolith electrolysis (MRE), and vacuum thermal dissociation, of which carbothermal reduction is one of the most promising method.
Solid carbon have been used as the reducing agent in carbothermal reduction process to produce FeSi (iron silicate) and SiC (silicon carbide). But the use of solid carbon requires pyrolysis of a carbonaceous material which includes an additional processing step that is needed to perform carbothermal reduction. Moreover, the use of solid carbon as a reducing agent leads to the formation of several compounds within the reaction chamber.
In this study, the authors Mr. Nithya Srimurugan and Prof. Sathyan Subbiah from the Extra Terrestrial Manufacturing (ExTeM) Research Centre, and the Department of Mechanical Engineering, Indian Institute of Technology (IIT) Madras, Chennai, India, have used methane gas as a reducing agent. Methane gas is available as a by-product from the Sabatier process used in the International Space Station (ISS) for the conversion of carbon dioxide to oxygen. This is also a more economical and viable option for carrying out carbothermal reduction process on the moon.
SiC has been noted as a by-product in carbo-thermal reduction investigations. But the process for extracting it viably has not been attempted.
SiC is a wide bandgap semiconductor material with properties that are well suited to handle the harsh environment on the moon. It is a perfect candidate for producing high temperature, high power electronic devices from lunar regolith. It possesses good mechanical strength, high corrosion resistance, and high erosion resistance to endure the abrading behaviour of lunar regolith particles. Thus, it can be used as reinforcements in lunar regolith composites for constructing radiation shields and habitats.
This method has significant potential in producing SiC from lunar regolith without requiring any reagents to be transported from the earth, on a manned lunar base in operation.
Dr. Shyama Narendranath, who is a Scientist at the Indian Space Research Organisation (ISRO), and who is also involved in the current and future ISRO’s chandrayaan missions, gave the following enthusiastic and appreciative comments on the work done by the authors as follows: “Building a long-term human presence on the Moon isn’t science fiction anymore — it’s a serious goal for India and other spacefaring nations. Instead of carrying everything from Earth (which is incredibly expensive), the smart strategy is simple: use what’s already there.
One promising technique is called carbothermal reduction. Think of it like “cooking” lunar soil at very high temperatures with carbon. This process pulls oxygen out of the minerals, releasing it for use.
In a recent work, researchers Nithya and Sathyan showed something exciting: by heating lunar soil simulant in a methane atmosphere, they not only helped drive this oxygen-extraction reaction, but also produced silicon carbide (SiC) — an extremely tough, heat-resistant material used in electronics and high-strength components. That’s a big step towards true self-reliance on the Moon.
With India’s growing lunar ambitions, led by organizations, studies like these show that future astronauts might one day breathe air and build habitats made from Moon soil itself!
In short: the Moon isn’t just a place to visit — it could become a place where we live off the land. And this research is an important step in making that possible.”
Article by Akshay Anantharaman
Click here for the original link to the paper
