Elon Musk Wants a Self-Growing City on the Moon Within 10 Years. Water Could Be the Biggest Problem
Elon Musk has put the Moon ahead of Mars in SpaceX's long-term settlement plans, saying the company could potentially build a “self-growing city” on the Moon in less than 10 years. But as scientists examine what it would take to support a large permanent population away from Earth, one basic resource is emerging as a potentially serious constraint: water.
Musk announced the strategic shift in February 2026, saying SpaceX had already moved its focus toward a lunar city because the Moon can be reached much more frequently than Mars. He argued that spacecraft could potentially launch toward the Moon about every 10 days, while Mars missions are constrained by planetary alignment and involve much longer travel times.
The timing is particularly interesting because a new scientific study published on September 14, 2026, examined whether the Moon's water resources could actually support large, self-sustaining settlements. Its conclusion raises difficult questions about the idea of eventually housing millions of people on the lunar surface.
What Elon Musk Means by a “Self-Growing” Moon City
Musk's proposal is not simply about sending astronauts to establish a small research base.
The idea is a settlement that gradually expands its own infrastructure and becomes less dependent on supplies shipped from Earth. In his February 8 post on X, Musk said SpaceX had shifted focus toward a self-growing lunar city that could potentially be achieved in less than a decade. He also said Mars remained part of the company's plans, with lunar development taking priority because it could progress faster.
The underlying concept is important. A truly self-sustaining settlement would eventually need to manufacture or extract many of the things it currently receives from Earth.
That could include construction materials, oxygen, water, fuel and components needed to maintain infrastructure.
NASA is pursuing a similar technological principle through in-situ resource utilization (ISRU), which means using resources found on the Moon rather than transporting everything from Earth. NASA says researchers are developing technologies to extract resources such as water and materials from lunar soil for life support, propulsion and other uses.
Why Water Could Become the Moon City's Biggest Constraint
Water is not merely something humans need to drink.
On the Moon, it could become an industrial resource.
Water can support drinking, hygiene and agriculture, but it can also be separated into hydrogen and oxygen. Those elements could potentially be used to produce rocket propellant and support other activities.
The Moon does contain water. NASA says observations from several missions have confirmed water ice in permanently shadowed regions near the lunar poles. Data from India's Chandrayaan-1 mission also contributed to the confirmation of water ice in permanently shadowed regions.
The problem is accessibility and scale.
A resource existing somewhere on the Moon does not mean it can easily be mined, processed and transported to a settlement.
The permanently shadowed regions where ice may survive are extremely cold, rugged and difficult to operate in. NASA identifies steep slopes, extreme temperatures, deep darkness and lunar dust as significant challenges for future resource extraction.
A New Study Raises Questions About Million-Person Lunar Cities
A study by researchers Martin Elvis and Jonathan C. McDowell, published in Frontiers in Space Technologies on September 14, examined whether lunar water could support a large settlement.
The researchers considered a highly optimistic scenario involving 1 billion tons of lunar water and very efficient recycling. Even under those assumptions, they concluded that the water would not provide indefinite sustainability for a lunar population of one million people.
That does not mean the Moon cannot support humans.
Instead, the study highlights the difference between a small lunar settlement and a large lunar city.
A settlement of hundreds or thousands of people could operate under much tighter resource constraints. A city containing hundreds of thousands or millions would require dramatically larger and more reliable supplies.
This distinction could become one of the central questions surrounding Musk's vision.
The Moon Has Water, But Mining It Is Another Matter
Scientists have spent years trying to determine how much lunar water exists and where it is located.
NASA's Lunar Reconnaissance Orbiter and other missions have mapped polar regions, while instruments such as NASA's Lunar Flashlight were designed to investigate water ice in permanently shadowed areas.
But researchers still have significant uncertainties about the abundance, distribution and physical form of lunar water.
That matters economically.
If water is concentrated in easily accessible deposits, future lunar operations could potentially extract it using robotic mining systems. If it is scattered through difficult terrain or mixed into regolith at low concentrations, extraction could require substantially more energy, machinery and infrastructure.
NASA is already treating this as a technology-development problem. Its Break the Ice Lunar Challenge was designed to encourage systems capable of excavating and moving lunar resources in the extreme environments found near the lunar poles.
Why SpaceX Prefers the Moon Before Mars
Musk's argument for prioritizing the Moon is largely based on logistics.
The Moon is roughly 384,000 kilometres from Earth, while Mars is tens of millions of kilometres away depending on the planets' positions.
A lunar settlement can therefore be supplied and upgraded much more frequently than a Mars settlement.
Musk specifically argued that missions to Mars depend on an approximately 26-month planetary cycle, whereas launches toward the Moon could occur much more frequently. He said this would allow SpaceX to iterate—meaning test, learn, improve and repeat—much faster on the Moon.
For an engineering project as complicated as a permanent off-Earth settlement, that difference could be significant.
A failed or damaged system on the Moon is still difficult to repair, but engineers have far more opportunities to send replacement equipment than they would have on Mars.
The Moon's South Pole Could Become the Key Battleground
The lunar South Pole is already attracting intense interest because of its combination of potential water resources and areas with relatively favourable illumination.
NASA says the region contains permanently shadowed areas that may preserve water and other volatile materials. At the same time, some nearby locations can receive sunlight useful for power generation.
That combination makes the South Pole strategically important.
But it also creates engineering complications. NASA's Moon Base architecture documents describe the South Pole as an environment with rugged terrain, deep craters, extreme shadows and prolonged periods of cold and darkness. Equipment will need to operate across both illuminated and permanently shadowed environments.
In practical terms, future lunar settlements may need to position power systems, habitats, mining equipment and transportation networks around the geography of the South Pole rather than simply building wherever there is empty land.
What a Self-Growing Lunar Economy Would Need
For Musk's vision to progress from a small base toward a genuinely self-growing city, several technologies would have to mature together.
Water extraction would be essential for life support and potentially fuel production.
Robotics could reduce the amount of dangerous manual work required from astronauts.
Local manufacturing could allow settlers to produce components and construction materials instead of importing everything from Earth.
Reliable power generation would be necessary for mining, manufacturing, communications and life-support systems.
Advanced recycling would reduce dependence on fresh supplies.
NASA is already developing technologies around several of these areas. Its current Moon Base approach is explicitly designed as a phased development process, gradually increasing capabilities rather than attempting to construct a complete lunar city in a single step.
The Business and Technology Implications
For investors and technology companies, the more important story may not be whether a million-person Moon city appears within a particular deadline.
The emerging lunar economy could create demand for technologies involving launch systems, robotics, communications, autonomous vehicles, power generation, resource extraction, advanced materials and life-support systems.
However, investors should distinguish between commercial opportunities created by lunar exploration and speculative claims about individual companies benefiting from a future Moon city.
SpaceX remains privately held, so Musk's lunar plans do not translate directly into a publicly traded “Moon stock.” Companies involved in aerospace and space infrastructure could potentially participate in the broader ecosystem, but the commercial winners will depend on contracts, technology readiness, economics and government spending.
The timeline itself should also be treated as Musk's stated ambition, not as a confirmed construction schedule.
What Investors and Space Watchers Should Monitor
Several developments will tell us whether the vision is becoming technically credible:
Successful and increasingly frequent Starship missions
Progress toward crewed lunar operations
Demonstrations of lunar water extraction
Advances in autonomous excavation and construction
Development of reliable lunar power systems
Evidence about the quantity and accessibility of polar ice
Growth of commercial lunar transportation and infrastructure
The economics of producing fuel and other resources on the Moon
The most important milestone may ultimately be relatively mundane: Can machines reliably extract useful quantities of lunar resources and turn them into something a settlement can actually use?
That is the bridge between a lunar outpost and a self-growing city.
Conclusion
Elon Musk's plan to prioritize a self-growing Moon city represents a significant shift from SpaceX's long-running emphasis on Mars. Musk says a lunar city could potentially be developed in less than 10 years because the Moon offers much more frequent access than Mars.
But the latest scientific research shows that reaching the Moon is only the beginning. Water availability, extraction difficulty, recycling, power, construction and local manufacturing will determine whether a permanent settlement can expand beyond a small base.
The key question for the coming years is therefore not simply whether humans can live on the Moon, but whether they can obtain enough local resources to keep a growing population supplied without depending indefinitely on Earth.
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This article is for informational and educational purposes only and should not be considered investment advice.