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This article was originally published on The conversation. (opens in a new tab) The publication contributed the article to Space.com’s Expert voices: editorial and in-depth analysis.
Michele Dello-Iacovo (opens in a new tab)Occasional Academic, UNSW Sydney
Serkan Saydam (opens in a new tab)Aboveground Mining, Future Mining, Mining Systems, UNSW Sydney
Like the Earth, planetary bodies such as the moon, Mars, asteroids and comets contain substantial deposits of valuable resources. This has caught the attention of both researchers and industry, with the hopes of someday mining them to support a space economy.
But creating any kind of off-Earth mining industry will be no small feat. Let’s take a look at what we’re up against.
Related: NASA just cut a 10 cent check to start lunar mining technology
Use of on-site resources
When you think of mines outside the Earth, you might imagine extracting materials from various bodies in space and bringing them back to Earth. But this is unlikely to be the first commercially viable example.
If we wanted to establish a permanent human presence on the moon, as NASA has proposed (opens in a new tab), we would need to supply the astronauts who live there. Resources such as water can only be recycled to a certain extent.
At the same time, the resources are extremely expensive to launch from Earth. As of 2018, it cost around A $ 3,645 (opens in a new tab) to throw one kilogram of material into low earth orbit and more to throw it higher, or to the moon. Materials mined in space are likely to be used in space, to help save on these costs.
Gathering the necessary materials on site is called “use of on-site resources”. It can involve anything from ice extraction to soil harvesting to build structures. NASA is currently exploring the possibility of building buildings on the moon with 3D printing (opens in a new tab).
Mining in space could also transform the management of satellites. Current practice is to deorbit satellites after 10-20 years when they run out of fuel. A noble goal of space companies like Orbit Fab is to design a type of satellite that can be refueled (opens in a new tab) using propellant collected in space.
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Even for satellites in low orbit, the energy required to reach them from the moon is less than that required to reach them from Earth.
What resources are there?
When it comes to mining opportunities outside the Earth, there are some resources that are both abundant and valuable. Some asteroids contain (opens in a new tab) large quantities of metals of the iron, nickel, gold and platinum group, which can be used for construction and electronics.
Lunar regolith (rock and soil) contains helium-3 (opens in a new tab), which could become a valuable resource in the future if nuclear fusion becomes viable and widespread. The British company Metalis has developed a process capable of extracting oxygen from the lunar regolith (opens in a new tab).
Ice should exist (opens in a new tab) on the surface of the moon, in permanently shadowed craters near its poles. We also think there is ice beneath the surface of Mars, asteroids and comets. This could be used to sustain life, or be broken down into oxygen and hydrogen and used as a propellant.
How would we mine in space?
My (Michael’s) Ph.D. thesis was to test how exploration techniques would work on the moon and Mars (opens in a new tab). Our other work included economic modeling for ice extraction on Mars (opens in a new tab)and computer modeling of tunnel stability (opens in a new tab) on the moon.
Some proposals for off-Earth mining are similar to mining on Earth. For example, we could mine the lunar regolith with a bucket wheel excavator (opens in a new tab)or mine an asteroid using a tunneling machine (opens in a new tab).
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Other proposals are more unknown, such as using a vacuum-like machine (opens in a new tab) to pull the regolith on a pipe (which has seen limited use in excavations on Earth).
Researchers from the University of New South Wales Sydney and the Australian National University propose to use biomining (opens in a new tab). In this, bacteria introduced into an asteroid would consume certain minerals and produce a gas, which could then be picked up and collected by a probe.
Huge challenges persist
Our work at UNSW’s Australian Center for Space Engineering Research (opens in a new tab) it involves finding ways to reduce risks in a space resource industry. It goes without saying that there are many technical and economic challenges.
The same launch costs that have so many eager to begin mining off-Earth also mean that getting mining equipment into space is expensive. Mining operations will need to be as light as possible to be cost-effective (or even feasible).
Also, the further away from Earth something is, the longer it will take to reach it. There is a delay of up to 40 minutes when sending a command to a Mars rover and finding out if it was successful.
The moon only has a 2.7 second delay for communications, and it may be easier to mine remotely. Objects close to the Earth also have Earth-like orbits and occasionally pass close to the Earth (opens in a new tab) at distances comparable to the moon. They are an ideal candidate for mining as they require little energy to reach and return from.
Extraction off-Earth is expected to be mostly automated or remotely controlled, given the additional challenges of sending humans into space, such as the need for life support, avoiding radiation, and additional launch costs.
However, even the mining systems on Earth are not yet fully automated. Robotics will have to improve before the asteroids can be mined.
While the spacecraft landed multiple times on asteroids and even recovered samples, which were returned to Woomera in South Australia, during Hayabusa missions 1 and 2 (opens in a new tab) – our overall success rate for landing on asteroids and comets is low.
In 2014, the Philae lander sent to Comet 67P / Churyumov / Gerasimenko famously fell into a ditch during a failed landing attempt.
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There are also environmental considerations. Spatial extraction can help reduce the amount of extraction (opens in a new tab) necessary on Earth. But that’s whether mining off Earth results in fewer rocket launches, and not more, or if resources are returned and used on Earth.
While gathering resources into space may mean not having to launch them from Earth, more launches could inevitably take place as the space economy grows.
Then there is the question of whether the proposed mining techniques will also work in space environments (opens in a new tab). Different planetary bodies have different (or none) atmospheres, gravity, geology, and electrostatic environments (for example, they may have electrically charged soil due to particles from the sun (opens in a new tab)).
How these conditions will affect off-Earth operations is still largely unknown.
But the work is in progress
Although it’s still early days, a number of companies are currently developing technologies for off-Earth mining, space resource exploration, and other uses in space.
The Canadian Space Mining Corporation (opens in a new tab) is developing the infrastructure needed to support life in space, including oxygen generators and other machinery.
US company OffWorld (opens in a new tab) is developing industrial robots for operations on Earth, Moon, asteroids and Mars. And the Asteroid Mining Corporation (opens in a new tab) it is also working to create a market for space resources.
This article was republished by The conversation (opens in a new tab) with Creative Commons license. Read the original article (opens in a new tab).
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