A few practices are essential for mission planners when it comes to the future of space exploration. The concept of In-Situ Resource Utilization is the most important. The ability to harvest ice, regolith, and other elements is crucial to mission success.
NASA planners are focused on finding the best way to produce oxygen gas from the Moon's surface dust in preparation for the Artemis missions. Estimates show that there is enough oxygen in the top ten meters of lunar regolith to create enough O2 for every person on Earth for the next 100,000 years.
The Moon has a thin atmosphere that is so thin that it is considered an airless body. There are lots of oxygen in lunar rocks and regolith. The lunar surface is covered in fine dust caused by billions of years of impacts by comets and meteorites.
John Grant is a lecturer in soil science at Southern Cross University, Australia, and he says that the Moon's regolith is 45% oxygen by content. Oxygen is bound up in oxidizer minerals such as magnesium and aluminum. The isoptic composition of these minerals is almost identical to minerals on Earth, which led to theories that the Earth-Moon system formed together billions of years ago.
It takes a lot of energy to break the chemical bonds in regolith, which is why it is necessary to extract oxygen for future astronauts and lunar inhabitants. This process is used to make metals, where melted-down oxides are subjected to electrical current to separate the minerals from the oxygen.
In this case, the oxygen gas is produced as a byproduct so that it can be used to make metals. Oxygen would be the main product and the metals would be set aside as a potentially useful byproduct, most likely for habitat construction. Grant explained in a recent article that the process is straightforward but suffers from two major obstacles when adapted for space.
I is very energy hungry. It would need to be supported by solar energy or other sources on the Moon. Industrial equipment is required to extract oxygen from regolith. We would need to apply heat or heat combined with solvent to convert solid metal oxide into liquid form. We have the technology to do this on Earth, but moving this apparatus to the Moon will be a huge challenge.
The location of the lunar base is shown. The credit is given to the SOM/ESA.
The process needs to be more energy efficient in order to be considered sustainable. The solar array could be positioned around the rim of the craters to provide an energy flow. It would still be a challenge to get the industrial equipment there.
There is still a question of how much oxygen we could extract if we established the infrastructure. Some estimates are possible if we consider the regolith that is easily accessible on the surface and the data provided by NASA and the LPI.
The lunar regolith contains over a ton of minerals and over a ton of oxygen. Humans need 800 grams of oxygen a day to survive. A person with 630 kilo of oxygen would be alive for about two years.
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We can extract all of the oxygen from the average depth of regolith on the Moon. The top ten metres of the Moon would provide enough oxygen to support all eight billion people on Earth for around 100,000 years.
The astronauts are on the Moon. The credits are from NASA.
Mineral prospecting is similar to estimating how an astronomer will present opportunities for ISRU. NASA recently announced that the metallic asteroid Psyche II might contain as much as $10,000 quadrillion worth of precious metals and ores. The Psyche asteroid will be studied closely by the orbiter in 2022, as it could be the core remnant of a planetoid that lost its outer layers.
Some people disagree with this assessment, saying that Pysche II's composition and density are not well-constrained. Estimates of this nature ignore the cost of taking that wealth, which requires extensive infrastructure to be built before. Hauling that kind of mass from the Asteroid Belt to Earth is a lot of work.
The same goes for asteroid mining, a potentially-lucrative venture that could result in trillions being mined from Near-Earth Asteroids in the near future. This is dependent on the creation of a robust space-mining infrastructure that is still in the conceptual stage. Since the 1960s, there have been proposed methods and pathways for establishing infrastructure on the Moon.
In the coming years, multiple missions will be sent to the Moon to investigate these possibilities further, two of which Grant cites in his article. NASA and the Australian Space Agency signed a deal in October to develop a small lunar rover that could be sent to the Moon in as little as six years. The purpose of this rover is to collect samples of lunar regolith and transfer them to a NASA-operated ISRU system on a commercial lunar lander.
NASA is designing a new spacesuit for Artemis astronauts. The xEMU is called Exploration Extravehicular Mobility Unit. Credit: NASA.
SAS, a startup based in Belgium, announced this summer that it was building three experimental reactor for the moon. The European Space Agency contracted them to develop a technology demonstrator that can harvest oxygen to make propellant for spaceships, air for astronauts, and metallic raw materials for equipment.
The company hopes to send the technology to the Moon as part of a planned demonstration mission by the European Space Agency. These and other technologies are being pursued to ensure that the return to the Moon will be a success.
The Conversation, NASA.
