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This topic is offered for NewMars members who might wish to contribute links, images or text about how to create tunnels on Mars.
The topic is available for those who might be inspired by the challenge of excavating material from the surface of Mars, include from the walls of Craters or the slopes of mountains.
The only known and confirmed method of excavating material from the surface of Mars (or from rocks found on the surface) is the rotating tool carried by rovers.
This success shows the way forward, if a group desires to excavate a passageway into the interior of a crater wall.
A rank and file array of small drills can perform the work. The work will take time, but so would any other method of removing material.
I just heard back from Cokoino about their robot kit. They have provided instructions to operate the kit from a computer, and I am attempting to find time to allocate to that project. However, their correspondence arrives ** just ** as we are launching this new topic.
Tunnels, caves and whatever other excavations are needed on Mars are going to be performed by robots, and many of these robots are going to be supervised by humans in orbit (like the ISS at Earth >> German laboratory demo) or from safe and secure habitats on Mars.
I predict that the count of tunnels excavated on Mars by humans with Jack hammers is going to be zero.
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Post #3: SpaceNut added the name of Elon Musk and his Boring Company
http://newmars.com/forums/viewtopic.php … 46#p237546
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Elon Musk's Boring TBM so far unless there are going to be other vendors for mars.
To which this is a mass to mars item along with many others that take a given level of power and or alterations before being used on mars.
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For SpaceNut re excavation topic: http://newmars.com/forums/viewtopic.php … 46#p237546
Thanks for addition of Elon Musk and Boring Company to the topic!
If you can find time, please see if there is any public informaiton about the nature of the boring equipment Musk is using.
The reason I ask is because it might work on Mars as is.
Or perhaps some adjustments are required. At this point all we know is that the machinery can did tunnels of substantial diameter in Earth regolith.
Earth has an atmosphere with oxygen. Does the machinery use any of that oxygen? I don't think we know.
The tailings have to be moved out of the excavated space. What tools are used for that?
Is the system automated? What maintenance is required, what is checked and what is changed?
Are lubricants used for the cutting operation?
Are lubricants used inside the machine?
Can the machine be shipped in sections that weigh less than 40 tons?
Thanks again for giving the new topic a boost.
(th)
Current Status of Mars Tunneling Equipment
Conceptual Stage:
Current discussions revolve around the concept of using tunneling technology for Mars habitats, providing protection from cosmic radiation and micrometeorites, and leveraging the thermal stability of the subsurface.
Earth-based Prototypes:
Companies like The Boring Company (TBC) are developing advanced, all-electric Tunnel Boring Machines (TBMs) for Earth-based projects (e.g., the Prufrock series, which creates a tunnel approximately 3.7m/12ft in diameter).Technology Transfer:
While TBC's current machines are unlikely to be deployed on Mars without significant modification, the technology and engineering experience gained (such as automation and faster boring speeds) are seen as foundational for developing future off-world systems.
Prototype Drills:
Research has been conducted on smaller-scale "3-meter-class Mars drill prototypes" for scientific exploration of the shallow subsurface, but these are for drilling, not large-scale tunneling for habitats.
Transportability:
A 3m-class TBM (or its segments) is considered potentially transportable by a SpaceX Starship, which has an 8m diameter cargo bay.Key Challenges for Martian TBMs
Atmosphere:
Earth TBMs use significant amounts of water for cooling and other operations, which would be a major challenge in Mars's cold, near-vacuum atmosphere.Automation:
Due to communication delays and the need for efficient pre-human construction, Martian equipment would require a high degree of automation and robotic operation.Geology & Materials:
The machines would need to be adapted to Mars's unique rock and soil conditions. Also, instead of concrete segments (which are heavy to transport), innovative methods like sintering the excavated rock or using local materials for tunnel lining would be necessary.In short, 3 m diameter equipment for Mars is an active area of conceptual development and technological aspiration, leveraging Earth-based innovations, but is not yet a developed or deployed product.
Elon Musk's Boring Company develops advanced tunnel boring machines (TBMs), like the Prufrock series, with the long-term goal of enabling underground Martian cities for radiation protection, resource extraction (ice/metals), and efficient habitat construction, potentially using Starship for transport, with Earth projects providing crucial tech and operational experience for Mars colonization needs. The technology focuses on rapid, automated tunneling, which is vital for establishing self-sufficient subterranean life on Mars, where surface conditions are harsh.
How Boring Company Tech Applies to Mars:
Radiation Shielding:
Mars' surface lacks atmosphere, exposing settlers to lethal radiation; burying habitats under Martian rock provides natural shielding.
Resource Utilization:
TBMs can excavate for essential water ice and minerals, crucial for life support and fuel.
Rapid Infrastructure:
High-speed, automated digging allows for quick creation of tunnels for transport (like Hyperloop) and pressurized living spaces, reducing human exposure to dangerous conditions.
Autonomous Operations:
Earth-based experience with "no prior site prep" TBMs (like Prufrock) prepares for robotic deployment on Mars for automated base building.Key Technologies & Challenges:
Prufrock TBMs:
Designed for rapid, continuous excavation, with capabilities to start digging immediately, a major leap from traditional methods.SpaceX Integration:
While Starship can carry heavy payloads, transporting massive TBMs (like 1,200-ton machines) poses a challenge, requiring multiple launches or lighter designs.
Atmospheric Advantage:
Mars' thin atmosphere makes underground Hyperloop tunnels ideal, as an artificial vacuum isn't needed.The Vision:
The Boring Company's work on Earth, including rapid tunneling for tunnels and loops, serves as a practical testbed for the advanced, automated digging needed for large-scale Martian settlements, fulfilling Musk's vision for a multi-planetary humanity.
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This post is a continuation of SpaceNut's #3 above, and of kbd512's post about use of CO2 for drilling, published in the kbd512 topic.
Kbd512's post is here http://newmars.com/forums/viewtopic.php … 61#p237561
I asked Gemini to ** think ** about the problem of running a large boring machine on Mars, and it settled on liquid CO2 (as kbd512 had done) but it ** did ** consider supercritical CO2. It ** also ** found a role for ordinary gas CO2 to blow fines if the exhaust from, the liquid CO2 feed is insufficient. It ** also ** warned that liquid CO2 might be ** too ** cold so it's use must be regulated closely by automation to insure the cooling is matched to the heat generated by cutting.
Conversation with Gemini
CO2 as coolant for drill on Mars - Hello Gemini! Thank you for your assistance with many previous requests. I'm hoping this one will be on the easy side compared to some. A small international online forum is thinking about how to adapt equipment and methods developed on Earth for the Mars environment. We are assuming no water but plenty of CO2 for cooling the drill heads of machines up to and including the Boring Company 3 meter tunneling machine. The question I have is: Of the three phases of CO2 that would apply, which do you think is a better bet for this application? Frozen CO2 (dry ice) has no place in this scenario. If you can find a chart showing the phases (that we can link to our presentation) that would be helpful. Please include details about how each phase would be used, assuming more than one phase would be useful.
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Hello! It’s great to see you and the forum diving into the practical engineering of Martian colonization. Adapting a 3-meter boring machine for Mars is no small feat, especially when you're swapping traditional liquid-coolants for the local atmosphere.Since you've ruled out dry ice (wise, as handling solids in a cooling loop is a mechanical nightmare), we are looking at Gas, Liquid, and Supercritical phases.
The Phase Diagram of Carbon Dioxide
To understand which phase is the "better bet," we have to look at the Martian environment. Mars has an average surface pressure of about 0.6% of Earth’s (approx. 0.6 kPa). On Earth, CO 2 usually skips the liquid phase (sublimes), but with a pressurized cooling system, we can access all three states.
1. Gaseous CO 2 (The Low-Complexity Choice)
This is the most straightforward method: compressing the thin Martian atmosphere and blowing it over the drill head.How it’s used: High-velocity jets of gas are directed at the cutting teeth to carry away heat and dust.
Pros: Minimal risk of leaks causing "freezing" issues; simple plumbing.
Cons: Very poor heat capacity. You would need massive volumes of gas to cool a 3-meter drill head, which consumes significant power for compression.
2. Liquid CO 2 (The Practical Middle Ground)
To get liquid CO 2 , you must keep the system pressurized above the triple point (5.1 atm).How it’s used: A closed-loop refrigeration cycle where liquid is pumped to the drill head. As it absorbs heat, it may partially boil (evaporative cooling), which is incredibly efficient at removing heat.
Pros: Much higher thermal conductivity than gas. It acts more like the traditional water-glycol systems used on Earth.
Cons: Requires a robust, sealed pressurized system. If a seal fails, the liquid flashes into gas instantly, potentially causing "ice" blockages of dry ice due to the Joule-Thomson effect.
3. Supercritical CO 2 (scCO 2 ) (The High-Performance Choice)
When CO 2 is heated above 31.1 ∘ C and pressurized above 72.8 atm, it becomes a supercritical fluid. It expands like a gas but has the density of a liquid.How it’s used: This is often used in high-end industrial "Minimum Quantity Lubrication" (MQL) systems. It is fed through the spindle directly to the cutting edge.
Pros: Superior "wetting" ability—it gets into microscopic cracks better than liquid and carries heat away faster than anything else.
Cons: Extreme pressure requirements. Engineering a 3-meter TBM (Tunnel Boring Machine) to maintain 73+ atm at the rotating seal of the cutter head is a massive structural challenge.
The Verdict: Which is the better bet?
For a machine as large as a Boring Company TBM, Liquid CO 2 is your best bet for the bulk cooling of the motor and hydraulics, while Gaseous CO 2 (specifically "cold gas" expanded from the liquid state) is best for clearing "fines" (dust) from the drill face.Why?
Supercritical is likely overkill and too "leaky" for a 3-meter rotating face.
Liquid allows you to use the phase change (boiling) to absorb massive amounts of latent heat produced by boring through Martian basalt or ice.
Summary Table
Phase Cooling Efficiency Complexity Martian Viability
Gas Low Low Good for dust clearing
Liquid High Medium Ideal for primary cooling
Supercritical Extreme Very High Likely too complex for TBM seals
Would you like me to run some rough calculations on the flow rate of liquid CO 2 required to cool a 3-meter drill head at full power?
***
I am delighted to see that your answer includes a role for gas to clear fines from the cut, because a traditional vacuum will not work on Mars. I'll publish your response and wait to see if anyone has a request or a question.
***
That is a fantastic catch by your forum! You’ve hit on a critical piece of Martian fluid dynamics: since the ambient pressure is so low ( 600 Pa), trying to "suck" debris away with a vacuum is like trying to use a straw in a room with no air. There just isn't enough atmospheric density to provide the necessary suction force.Using Gaseous CO 2 as a "positive pressure" blower is the only way to move that regolith. Essentially, you'd be using the exhaust from your liquid cooling system to create a high-velocity jet that pushes the "fines" away from the cutting face and back into the conveyor system.
A Quick Engineering Note for the Forum:
When your liquid CO 2 absorbs heat and transitions to gas for the "clearance" phase, it undergoes adiabatic expansion. This will cause the gas to get incredibly cold—potentially cold enough to turn into dry ice snow right at the nozzle.To prevent the drill head from clogging with its own coolant, the TBM design might actually need to pre-heat the exhaust gas slightly before it hits the cutting face, or ensure the mechanical friction of the drill provides enough heat to keep the CO 2 in a gaseous state.
I’ll be here when the forum weighs in! Since you mentioned the 3-meter Boring Company machine, would you like me to look into the specific energy requirements for compressing Martian air into that liquid state, or perhaps discuss the metallurgy needed to prevent the drill bits from becoming brittle in those CO 2 temperatures?
For kbd512 ... do you think automation (sensors and processor and valve control) can deal with the complexity of keeping coolant flow matched to the heat output from the drill head?
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