The Place of Mars on the Interstellar Roadmap

The great post-Apollo slowdown

It is time to reflect on humanity’s progress so far into the Solar System, in view of two anniversaries. The first was on 28 May 2015, which was the 25th anniversary of Robert Zubrin’s first public presentation of his Mars Direct plan, to a conference of the National Space Society. The second will come in four years time, on 20 July 2019, and no space-aware person will need to be reminded what that signifies.

Both anniversaries are the occasion for some soul-searching among those who, like myself, envisage human expansion into the Solar System and the Galaxy. Zubrin’s Mars Direct plan was the intellectual breakthrough which first demonstrated how the use of extraterrestrial resources, specifically the martian atmosphere, could be integrated into a mission design for exploring Mars. But despite considerable enthusiasm and the support of a NASA Administrator, over the following quarter of a century no government authorised its space agency to officially adopt the plan. The closest that NASA came was the Constellation programme, which de-prioritised Mars until after a lunar return. Governments, it seems, are happy to pay for the occasional rover to do science on Mars, but not to commit to sending astronauts there.

Or even back to the Moon. From Neil Armstrong’s first step on the lunar surface in July 1969 to Eugene Cernan’s last in December 1972, twelve American men (eleven test pilots and one scientist) walked on the Moon. The fate of Constellation, cancelled by the Obama administration in 2010, demonstrates that whatever factor it was that sent the Apollo astronauts to the Moon, that factor is no longer effective. Russia is in no fit state to resume its lunar ambitions either, and talk about the Chinese sending their astronauts to the Moon remains speculation.

This slowdown in the rate of progress in astronautics since Apollo is, incidentally, one of the reasons which incline me towards a plateaunian rather than a singularitarian point of view. Technology cannot be driven forward indefinitely, progress is beginning to top out. Arthur C. Clarke wrote that any sufficiently advanced technology would appear to those below that level of development to be like magic, but the converse is not necessarily true: the fact that we can imagine magic does not prove that any real-world technology can exist that does the same thing.

The significance of Mars

The Moon is attractive for human exploration and eventual settlement because of its closeness and all-year-round accessibility; Venus because of its closely Earthlike gravity; and the asteroids because of their resource richness and ease of access directly from space. Yet I believe that it is probably correct to continue to view Mars as the test case for whether human beings can live permanently away from Earth. Mars possesses mineral resources, some basic gravity, atmospheric gas and a working flat surface to stand on and build on over its entire surface. Cold high-altitude deserts on Earth offer a fair approximation to martian conditions.

I conclude that if we cannot make it on Mars, then we’re not likely to be able to settle anywhere else beyond Earth, either in our own Solar System, or beyond.

The one factor which could alter this conclusion would be if humans really were unable to live a healthy lifetime in martian gravity, which makes our current ignorance on this point so frustrating. Then the first extraterrestrial colonists would be obliged to first solve the problems of maintaining high-tech habitable structures stably in the venusian atmosphere, or of manufacturing them out of primordial debris in open space.

Looking out onto the galactic stage, in the absence of magical new technologies of propulsion and power supply, a civilisation based on Earth alone will be able to send a few small-scale interstellar probes to the nearest stars, but upgrading to something the size of Daedalus, let alone a worldship capable of transporting human passengers, will remain beyond our reach. An interplanetary civilisation is mandated, both to mature the necessary technologies, and to provide the industrial muscle necessary for such large-scale programmes.

Students of interstellar travel therefore need to consider why the post-Apollo slowdown has happened, and how astronauts might eventually get to Mars.

How to get to Mars

There are basically two paradigms of Mars exploration and settlement. The heroic pattern is exemplified by Apollo: a one-off programme which depends upon political will for its continuation, and is cancelled as soon as that will evaporates, unless it has managed to acquire such bureaucratic inertia that cancellation has become politically impossible. In the case of NASA, while the organisation itself seems to be immune to abolition to the extent that it is tasked with make-work programmes such as the SLS rocket in order to maintain its basic workforce and infrastructure, individual programmes undertaken by NASA may be cancelled if they are perceived to be inordinately risky or likely to over-run their costs.

Against this, there is what we shall call the systemic paradigm, thus one which arises out of the overall social system as a whole. This is how globalisation took effect on our own planet: not by a Napoleon or a Caesar decreeing that the world would be conquered, but by a myriad organisations within society all pursuing their own separate goals, with the long-term effect of the creeping spread of originally European, now global culture worldwide. The manner in which Britain acquired a global empire without really trying is part of the broader globalisation process.

Given that political conditions at present are not conducive to any one or more governments undertaking manned Mars exploration, and in fact have never yet been conducive to that goal, those who look forward to that exploration – and particularly if they hope that it will buck the Apollo pattern and lead on to greater things – need to consider how systemic Mars exploration and settlement might work.

There is talk about deliberately destroying the 100-billion-dollar investment of the International Space Station by de-orbiting the station and crashing the wreckage into the Pacific Ocean in the 2020s in order to save money for exploration beyond low Earth orbit. It must be clear that systemic growth is the opposite of this, being founded on a build-up of economically self-sustaining infrastructure which has opened up large-scale markets for spaceflight.

For the systemic growth of astronautics to set up the conditions for astronauts to reach Mars safely and sustainably, a situation needs to be arrived at in which the space passenger industry is flying, say, a hundred people to the Moon and back every year, and a thousand people to orbit and back every month, for a variety of purposes, of which space tourism is likely to be much the largest.

Life support for long-term survival on Earth and off it

Developing space passenger transport depends upon engineering companies such as SpaceX, Bigelow Aerospace, XCOR Aerospace, Virgin Galactic and Reaction Engines for progress. Relatively small, non-commercial groups of supporters can only cheer from the sidelines, and explain to the doubters why continued growth of technology and the economy is both necessary and possible.

But there is a major lacuna in preparations for extraterrestrial settlement which is so far as I know not really being addressed at present.

How might people live on Mars, or in a space colony, or a starship, or on an exosolar planet or space colony? The dominant life mode in developed countries on Earth today is for people to live in cities, supplied by an agricultural hinterland. Away from Earth there is no hinterland: a new mode of life, that of the self-contained, self-sufficient city is mandated.

But if people can live in self-sufficient cities in space, then they can do so equally well on the more hostile parts of Earth’s surface, particularly as on Earth it is not necessary to close the cycle of breathing gases. Closing the toilet waste to food production cycle can be done separately first.

Charles Cockell argued that it is unlikely that large human populations will ever live on Mars (and therefore by implication on any Mars-like exosolar planet), because the conditions there are more hostile than Earth’s own polar regions. Polar deserts on Earth have a very low population density, and have so far failed to attract immigrants hoping for a new life of opportunity. But this argument can be inverted: before settling Mars, a growth-capable method of settling Earth’s own desert regions needs to be demonstrated.

A programme for the growth of self-sufficient cities

What do I have in mind? Something like the Biosphere 2 experiment in Arizona (but without the need to hermetically seal off the atmosphere), like the Mars analogue stations operated by the Mars Society on Devon Island and in Utah, and like NASA’s own Mars analogue research station in Hawaii. But all of these were designed as temporary demonstrations. Because Biosphere 2 was too ambitious, its high cost (about $15 million per person per year) rendered it unsustainable. Meanwhile the Mars simulation experiments are designed around simulating conditions on Mars for an Apollo-style visit, albeit one lasting a year rather than a couple of days. Again, they are places to visit, not to live in.

The Mars analogue bases on Earth need now to address the same problem being faced by promoters of commercial space transport: how to kick-start a virtuous spiral of falling costs and accelerating growth. They need to become places attractive enough to live in, not just to visit.

One benefit of such a programme would be its applicability to human life both away from Earth, but also on it. In order to make civilisation sustainable in the long term on Earth itself, cities must develop a much higher degree of self-sufficiency. Clearly there has already been much movement in this direction, with the growth of recycling schemes for domestic and industrial waste, and a new vogue for food production under controlled conditions within cities, albeit still on a small scale.

This is therefore an existing trend working in favour of space and planetary colonisation.

What space advocates can do on top of this, however, is to demonstrate the first self-sustainable city in what would formerly have been regarded as an impossible desert location. This could first be attempted in a terrestrial desert. It is first necessary to show that such a colony can be an attractive and economically viable place for people to live permanently, and therefore capable of long-term growth. People must be willing and financially able to migrate permanently to a settlement in the Canadian Arctic, or the Sahara Desert, or an uninhabited island, or wherever it may be.

But that will only suffice for an initial proof of concept. Grow the settlement to even the size of a modest town, and the government which exercises sovereignty over that patch of ground will begin to take an interest. As Zubrin wrote, anywhere you go on Earth nowadays, the cops are too close to allow any kind of political freedom.

That is why I believe we must revisit the proposal, made by Marshall Savage in his book The Millennial Project, to establish self-sufficient cities which are floating islands anchored in international waters in the tropical oceans. He argued that if we are to colonise space, we should start with the easiest space, in order to avoid over-reach and disappointment.

With our eyes focused on Mars or on the billions of Mars-analogues scattered throughout the great interstellar beyond, it can be easy to believe that a simple programme analogous to Apollo or the Space Shuttle would be enough to build the ships which open the gates to a future in the stars. I believe this is an illusion. What we are really attempting to do is to create an entirely new mode of human life, one in which all a person’s material needs are supplied locally, and all waste products recycled locally. We are seeking to live in environments which have never yet sustained any kind of life, with the novel challenges of reduced or microgravity, ionising radiation, vacuum or else an unbreathable toxic atmosphere.

Overcoming all these challenges in one fell swoop is not practical, and certain to lead to programme cancellation. The attempt to do so would be as much an over-reach as was Apollo. Our motto must be to do things one step at a time – the way evolution does things.

We should therefore focus for now on sustainable living, applicable both on Earth and beyond it, and on the engineering challenges of constructing artificial islands in international waters. Clearly we also need the inspirational design studies for interstellar probes and worldships, in order to lay out the longer term prospects. But not at the expense of the shorter term work which is indispensable if we are eventually to arrive at the goal of interstellar growth.