Home South pole ice There is enough oxygen in the lunar regolith to support billions of people on the moon

There is enough oxygen in the lunar regolith to support billions of people on the moon



When it comes to the future of space exploration, a handful of practices are essential for mission planners. Most important of these is the concept of in situ resource use (ISRU), providing food, water, building materials and other vital items using local resources. And when it comes to missions destined for the Moon and Mars in the years to come, the ability to harvest ice, regolith, and other items is crucial to mission success.

In preparation for the Artemis missions, NASA planners are focusing on finding the best way to produce gaseous oxygen (O2) of all the elemental oxygen trapped in the Moon’s surface dust (aka lunar regolith). In fact, current estimates indicate that there is enough elemental oxygen contained in the first ten meters (33 feet) of the lunar regolith to create enough O2 for every person on Earth for the next 100,000 years – more than enough for a lunar colony!

While the Moon has a very thin atmosphere that contains elemental oxygen, it is so thin that scientists characterize the Moon as an “airless body”. But in the lunar regolith, the fine powder and rocks that cover the surface, there are abundant amounts of oxygen in the lunar rocks and regolith. Also known as “Moondust”, this fine dust permeates the lunar surface and is the result of billions of years of meteor and comet impacts.

According to John Grant, senior lecturer in soil science at Southern Cross University in Australia, the moon’s regolith contains about 45% oxygen. However, this oxygen is linked to oxidized minerals, especially silica, aluminum, iron and magnesium. The isoptic composition of these minerals is almost identical to that of minerals on Earth, which has led to theories that the Earth-Moon system formed billions of years ago (a.k.a. the impact hypothesis giant).

However, in order for this oxygen to be usable by future astronauts and lunar inhabitants, it must be extracted from all that regolith, which requires a significant amount of energy to break chemical bonds. On Earth, this process (called electrolysis) is commonly used to make metals, where molten oxides are subjected to an electric current to separate minerals from oxygen.

In this case, gaseous oxygen is produced as a by-product so that metals can be produced for construction and manufacturing purposes. But on the Moon, oxygen would be the main product while metals would be set aside as a potentially useful by-product – most likely for habitat building. As Grant explained in a recent article in The conversation, the process is simple but suffers from two major obstacles when it is adapted to the space:

“[I]It is very energy intensive. To be sustainable, it should be supported by solar power or other energy sources available on the Moon. The extraction of oxygen from regolith would also require significant industrial equipment. We should first convert the solid metal oxide to liquid form, either by applying heat or by combining heat with solvents or electrolytes. We have the technology to do it on Earth, but moving this device to the Moon – and generating enough energy to operate it – will be a tall order.

ESA’s moon base, showing its location in Shackleton Crater. Credit: SOM / ESA

In short, the process has to be much more energy efficient to be considered sustainable, which could be accomplished with solar power. Around the Aitken Basin at the South Pole, solar panels could be positioned around the edge of permanently shaded craters to provide an uninterrupted flow of energy. But getting industrial equipment there would still be a monumental challenge.

But if and when we have established the infrastructure, there remains the question of how much oxygen we could extract. As Grant points out, if we consider only the regolith that is easily accessible on the surface and we take into account data provided by NASA and the Lunar Planetary Institute (LPI), some estimates are possible:

“Each cubic meter of lunar regolith contains an average of 1.4 tonnes of minerals, including about 630 kilograms of oxygen. According to NASA, humans need to breathe about 800 grams of oxygen per day to survive. Thus, 630 kg of oxygen would keep a person alive for about two years (or a little more).

“Now suppose the average depth of the regolith on the Moon is about ten meters and we can get all the oxygen out of it. This means that the top ten meters of the Moon’s surface would provide enough oxygen to support the eight billion people on Earth for about 100,000 years.

Illustration of Artemis astronauts on the moon. Credit: NASA

In many ways, estimating how an astronomical body will present opportunities for ISRU is like prospecting for minerals. For example, NASA recently announced that the metallic asteroid Psyche II could hold up to $ 10,000 quadrillion of precious metals and minerals. In 2022, the Psyche The orbiter will meet this asteroid, which could be the central remnant of a planetoid that has lost its outer layers, to study it closely.

Of course, some do not agree with this assessment, citing that the composition and density of Pysche II is not particularly well constrained. For others, estimates of this nature ignore the simple cost of extracting this wealth, which would require the prior construction of significant infrastructure. And even then, transporting this kind of mass from the asteroid belt to Earth presents many logistical challenges.

The same goes for asteroid mining, a potentially lucrative venture that could result in the mining of trillions of near-Earth asteroids (NEA) in the near future. However, it also depends on the creation of a robust space mining infrastructure which is still in the conceptual stage. Fortunately, when it comes to establishing an ISRU-related infrastructure on the Moon, the proposed methods and pathways have been in place since the 1960s.

In the years to come, several missions will be sent to the Moon to explore these possibilities, two of which Grant cites in his article. At the beginning of October, NASA signed an agreement with the Australian Space Agency to develop a small lunar rover that could be sent to the Moon as early as 2026. The goal of this rover will be to collect samples of lunar regolith and transfer them to a NASA. – operation of the ISRU system on a commercial lunar lander.

Artist’s illustration of the new spacesuit that NASA is designing for Artemis astronauts. This is called the xEMU, or Exploration Extravehicular Mobility Unit. Credit: NASA

In addition, the Belgian startup Space Applications Systems (SAS) announced last summer that it was building three experimental reactors for the Moon. They were one of four finalists selected by the European Space Agency (ESA) to develop a compact technology demonstrator capable of harvesting oxygen to make propellants for spacecraft, air for astronauts and materials. metal raw materials for equipment.

The company hopes to send the technology to the moon as part of an ESA ISRU demonstration mission, which is currently slated to reach the moon by 2025. These and other technologies are being pursued to ensure the long-awaited return. of humanity on the moon. will be to say.

Further reading: The conversation, Nasa