Issue #1(27) 2021 Opinion

On Mars as it is on Earth - preparing for settlement

James Vaughan
James Vaughan
Stephen Ashworth Voltaire Foundation, Oxford University, England

Mars has long been a target for future human settlement, but the more the space community thinks about it, the more challenging it seems. Stephen Ashworth reviews some of the issues and proposes an interim solution that he hopes will inspire others to act.

A huge amount of interest has been generated in recent months by the flight tests of Starship, SpaceX’s super-heavy rocket designed to enable the colonisation of Mars. Meanwhile, the Mars Society has attracted entries from no fewer than 175 teams from around the world for its Mars City State Design Competition, exploring architectural concepts for a Martian city of one million inhabitants. And in February 2021, three new robotic explorers from the USA, China and the United Arab Emirates arrived successfully at Mars.

Momentum is thus building towards astronaut flights to Mars within as little as the next 10 or 20 years, and there is an increasingly real possibility that a permanent settlement will have been established on the red planet before the end of the century.

A self-sufficient human colony on Mars would clearly be of immense value. It would not only serve as backup in the event of any global downturn in the progress of civilisation on Earth, whether through political extremism, economic collapse, war, or environmental disaster. It would also act as proof of concept for the view that humanity has an open-ended future of expansion into the rest of the universe, and by doing so help to ensure the security of life on Earth as well. There are, however, two problems with this rosy vision.

The three-acre Biosphere 2 research facility in Oracle, Arizona.The three-acre Biosphere 2 research facility in Oracle, Arizona. This 1990s project had the dual vision of creating new ways of living for the future not only on Earth but on Mars.

Mars: awesome or awful?

A self-sufficient human colony on Mars would clearly be of immense value

Firstly, we have a pretty good idea by now what an initial astronaut exploration mission to Mars would look like. Our view is informed, among others, by the high-fidelity simulations conducted in remote locations on Earth by NASA in collaboration with the University of Hawaii (HI-SEAS); the European Space Agency (ESA) with Roscosmos (Mars-500); and the Mars Society (Flashline Mars Arctic Research Station and Mars Desert Research Station). But a permanent settlement would be a different matter:

  • Instead of half a dozen astronauts there would need to be thousands (Elon Musk has stated a goal for self-sufficiency of one million people)
  • A large-scale closed-cycle ecological life-support system would need to be in place
  • There would need to be a good understanding of human health factors within a relatively confined, hermetically sealed environment, including lifelong nutritional needs, the interactions between humans and their microbiota, and fertility and childbearing on a low-gravity world
  • Recycling of all kinds of waste, discarded equipment and clothing would need to have been brought to a high level of completeness
  • Local resources would need to be mined and used to build machines and habitable infrastructure and replenish losses
    of consumables
  • Questions of the political organisation of the colony, its constitution, values and relationships with other colonies and with Earth would become unavoidable
  • Returning everybody to Earth in the event of a malfunction or a health crisis would be impossible.

As Elon Musk likes to emphasise, it is a critical question whether the settlement would be able to continue to survive and prosper if the supply line from Earth was cut for any reason.

In fact a settlement on Mars would represent a transition in human life as profound as the historical changes from a nomadic tribal existence to settled agricultural village life, and subsequently from that to industrial city life. On Mars (or anywhere beyond) all life-support functions would have to be contained within the built infrastructure, without the benefit of being refreshed by interactions with a global atmosphere, hydrosphere and biosphere.

All manufacturing would have to be local, rather than integrated into the global trading networks and markets that we have on Earth. And the trend of the past 10,000 years, in which humans have spent progressively less of their lives under open skies and more under artificial roofs, would have to be taken to its logical conclusion: permanent lifelong shelter from the vicissitudes of the natural environment.

A settlement on Mars would represent a transition in human life as profound as the historical changes from a nomadic tribal existence to settled agricultural village life

In view of the many difficulties, some well-informed writers have doubted whether Mars colonisation is a practical or possible option for humanity. In 2002, Interdisciplinary Science Reviews published an article by Charles Cockell, Professor of Astrobiology at the University of Edinburgh, with the challenging title ‘Mars is an awful place to live’ (see vol. 27, no.1, p.32-38). Cockell - an experienced polar explorer - drew the comparison between Mars and the terrestrial Arctic and Antarctic, pointing out that Earth’s polar regions are vastly more hospitable than anywhere on Mars, yet they do not attract immigrants seeking a land of opportunity. The more natural reaction, he thought, would surely echo the words of Robert Falcon Scott on his arrival at the South Pole in 1912: “Great God, this is an awful place!”

Cockell took issue with the analogy of expansion into the American West. In addition to the physical stresses of life on Mars unknown to historic migrations on Earth, he argued that the political freedom of future Martians would be severely constrained by the necessities of survival. This argument is a direct attack on Robert Zubrin’s rationale for settling Mars, set out in the Epilogue of his well-known book The Case for Mars.

The only hope for Mars as a second home for humanity, Cockell opined in his article, would be terraforming. Without a sufficiently Earth-like surface environment for people to be able to move around freely, Mars in his view offers only the prospect of isolated scientific outposts, human-tended mining operations and centres for extreme adventure tourism.

Since all other possible extraterrestrial locations of human settlement - such as the asteroid belt or the icy moons of the outer solar system - are considerably more hostile than Mars, Cockell’s argument has the effect of confining humanity (at least in its biological form) to Earth for the remainder of its existence.

NOAA’s Global Monitoring Laboratory at the South Pole.NOAA’s Global Monitoring Laboratory at the South Pole. Despite harsh living conditions the environment is vastly more hospitable than anywhere on Mars.

Mars: a distraction?

A second problem is the existence of a common popular trope to the effect that an interest in cities on Mars is incompatible with taking good care of the natural environment on Earth. An opinion has emerged that colonising Mars means “trashing planet Earth and moving on” (a quotation from a recent discussion between the author and a highly respected space scientist in the pages of Spaceflight, February 2021). However, the idea of a rapacious capitalist elite laying waste to Earth and then fleeing, locust-like, to wreak similar havoc on other planets is an old one (for example, the 1989 novel and BBC television serial Stark by British comedian Ben Elton).

Arguably, this criticism of space settlement is nonsensical when examined in detail. It is literally not within human technical capabilities to remove more than 99 percent of Earth’s atmosphere, freeze its oceans solid and sterilise its surface to the extent seen on Mars; in other words, it is a practical impossibility that human civilisation could ‘trash’ Earth to such an extent that Mars - let alone any other world in the Solar System - became a more environmentally attractive place to live.

When one considers the problems of settling Mars listed above, the idea becomes even more implausible. The unearthly surface conditions, combined with the unprecedented attempt to set up a way of life never before attempted, will inevitably require a period of acclimatisation lasting perhaps decades, more plausibly centuries, during which the embryonic Mars civilisation will need as much support from a peaceful, prosperous Earth as a new-born baby does from its mother.

But surely, some would suggest, industrial civilisation on Earth is unsustainable, especially if climate change is an immediate existential threat. This brings us to another essential point in favour of Mars colonisation and against the myth that it would detract from environmental responsibility on the mother planet. Some 250 years since steam was first raised in the Industrial Revolution, civilisation has still not found a long-term equilibrium even on its planet of origin. Its growth has benefitted immensely from the presence of concentrated deposits of minerals and energy, from an open land frontier and a pool of cheap labour, but that time is drawing to a close.

Artist’s impression showing the first phase of Dubai’s Mars Science City.Artist’s impression showing the first phase of Dubai’s Mars Science City.

If modern civilisation is to continue on Earth, then it must of necessity continue an existing trend of developing industrial practices which neither draw unsustainably on the natural environment for raw resources, nor wastefully deposit effluents into that environment. Energy supply needs to move away from fossil fuels to long-lasting sources such as geothermal, nuclear fission and fusion, as well as battery power recharged from intermittent local wind and sun. Food supply needs to greatly reduce its demands on land, water and energy, with the progressive replacement of animal products with cultured forms of milk and meat being an important recent innovation. All manufacturing processes need to become more energy-efficient, and waste products recycled rather than simply dumped in a hole in the ground or flushed out into the oceans.

It should be clear that all these trends are essential, not only to make civilisation sustainable on Earth, but equally to do so on Mars. For on the red planet, exploitation of a natural environment containing a rich biosphere and concentrated fuels is not possible, because it does not exist.

Earth’s polar regions are vastly more hospitable than anywhere on Mars, yet they do not attract immigrants

Therefore, the supposed choice between Earth and Mars is an illusion. The real choice humanity faces is between industrial civilisation and a return to the Middle Ages - between high-tech and low-tech futures. If we can continue to develop our cities to a level where they are truly sustainable on Earth, then with relatively minor modifications the same technologies will be equally applicable to self-sufficient colonies on Mars and beyond.

It is striking that the same logic lay behind the Arizona-based Biosphere 2 project of the 1990s. The Biospherians studied the interaction of the human technosphere with its supporting biosphere in order to inform projects both to make our cities sustainable on Earth, and to construct new ones on Mars - this dual vision runs through their writings.

A similar logic applies to economic growth, which is intimately connected with technological progress. A future of continued growth inevitably entails human expansion into the rest of the Solar System. A zero-growth future is hardly conceivable without draconian restrictions on political and economic freedom together with a drastically reduced global population.

As Arthur C Clarke wrote, “The choice, as Wells once said, is the Universe – or nothing. […] The challenge of the great spaces between the worlds is a stupendous one; but if we fail to meet it, the story of our race will be drawing to its close.”

The HI-SEAS Valoria 1 Mars mission on Hawaii and Kevin PrattThe HI-SEAS Valoria 1 Mars mission on Hawaii and (bottom): Engineering Officer Kevin Pratt (left) and Commander Michaela Musilova perform an emergency engineering ‘Marswalk’ to turn on a backup power source during a storm.

Planetopolis: a business solution?

To a large extent, the technologies needed for civilised life on Mars overlap with those needed for a similar standard of life on Earth, but they are still at an early stage of development. At the same time, conditions on Mars are more severe than those on the most remote and hostile deserts on Earth, and obviously the costs of transport between Earth and Mars are vastly greater than those for access to anywhere on Earth.

Given these facts, there are two logical consequences.

Firstly, self-sufficient urban settlements will be established in terrestrial deserts before they appear on Mars. The first settlers on Mars will have a hard time of it, as they deal with gravity, radiation levels and a local resource base that is different from any found on Earth. At the same time their colony will need to solve all the problems of living in a small-scale, closed-cycle ecology, organising their environmentally stressed society and mastering highly efficient methods of local manufacturing and recycling. But the latter set of problems are not specific to Mars: they can be solved in a series of terrestrial desert settlements first and matured so they can be transferred to Mars. This would increase the chance of success on Mars.

Secondly, such settlements will carry forward the dual vision of Biosphere 2. They will be designed to create new ways of living for the future not only on Earth but on Mars, ultimately to enable an unlimited human future beyond Mars. The builders of Biosphere 2 originally hoped that their investment might be recouped by building spinoff biospheres for other ecologically conscious groups worldwide in an environment of growing interest in science and eco-tourism. They expected to see their project lead on to Biospheres 3, 4 and so on. It is a shame that this did not happen but it is not too late to pick up the threads of their vision now.

But who will pay for it, given that the original Biosphere 2 cost in the region of US$200 million for construction and two long-term missions? Clearly, in order to be a success, any future project must evolve towards economic viability.

On the red planet, exploitation of a natural environment containing a rich biosphere and concentrated fuels is not possible, because it does not exist

The example of Elon Musk and SpaceX demonstrates a workable way forward. Musk’s business activities, firstly with PayPal and later with SpaceX, generated profits, and a fraction of the money earned has now been devoted towards developing the visionary Starship system with no expectation of immediate financial return. In addition, SpaceX’s commercial work with large rockets feeds into the technologies required for the visionary Earth-Mars transport system for which a market does not yet exist.

A prospective future company – let’s call it Planetopolis - devoted to building desert settlements on Earth as precursors of sustainable cities on both Earth and Mars offers a potential solution. Although it will require a core profit-making business, which will pay for and feed technologies into the visionary side of its activities, it follows a business model that is already being developed by a range of new companies in a variety of different fields, which include:

  • Non-fossil fuel energy generation, including nuclear fusion and geothermal power
  • Electrified and more efficient terrestrial transport (areas in which Elon Musk’s companies are active)
  • Cultured meat and milk products, replacing the inefficiencies, cruelties and contamination risks of modern animal farming
  • Systems for treatment and recycling of human waste from off-grid dwellings
  • Robotics, artificial intelligence and brain-computer interfacing
  • Space transport systems.

One can, therefore, imagine Planetopolis as a company whose initial business plan is based on the manufacture of components for buildings, which in due course graduates towards the construction of entire buildings, then of entire integrated housing and business estates. At this point the tools will be in hand - and hopefully the funds - to set up an experimental desert community. That community would in turn be a testing ground for new technologies - for construction, recycling, local manufacturing and food production - which feed back into marketable products that improve life in mainstream society.

The trick seems to be to identify new technologies which are just at the point where they are ready for large-scale economic application: too early and the technology is not yet mature; too late and everybody is already using it.

The number of innovative new start-ups appearing in the past two decades demonstrates that such opportunities exist, for those willing to look for them. The continuing environmental problems of planet Earth demonstrate that there is much work still to be done, and therefore many opportunities for a company running on the lines indicated.

Self-sufficient urban settlements will be established in terrestrial deserts before they appear on Mars

So when am I going to register Planetopolis with the authorities? Not yet. The first step is to develop a business plan leading to a marketable product and, for that, collaborators are needed - a board of advisors and a community of people with technical knowledge at the start of their careers, who will go on to run the company. Any offers?

Terraforming of Mars, as in this illustration of Omaha CraterTerraforming of Mars, as in this illustration of Omaha Crater, may ultimately be the best solution to long-term occupancy of the red planet (see ‘Developing Mars’, ROOM #15, 2018).

About the author

Stephen Livesey Ashworth is a long-standing Fellow of the British Interplanetary Society and has written numerous popular articles as well as 13 technical papers on different aspects of spaceflight. His novel The Moonstormers is available in electronic formats from He lives in Oxford, UK, works in academic publishing within Oxford University, and posts occasional blogs on spaceflight and related matters to his website at

If you've enjoyed reading this article, please consider subscribing to ROOM Space Journal to gain full access to current articles and receive your own print and/or digital copies of ROOM delivered direct to your door or electronically.

Popular articles

See also


Flouting the rules on satellite registrations


Preventing pilot spatial disorientation


Urgent action needed to avert space debris threat

Popular articles


Is NewSpace really so new?

Artistic interpretation of Lunar Gateway, a habitable station in lunar orbit that will be critical to sustainable lunar exploration and will serve as a model for future missions to Mars. Specials

A shared vision for space exploration