The Space Reviewin association with SpaceNews

ISDC 2024

Mars base illustration
As attractive as a Mars base may sound, a better case can be made for establishing a colony on the Moon first. (credit: NASA)

Colonize the Moon before Mars

There are a number of reasons that the Moon is the best place to start space colonization, but the basis of most of them are its proximity to the Earth. Most of these stem from the lower cost of access to the Moon. There are also important engineering, economic and political advantages to starting colonization with the Moon. Before discussing the advantages of the Moon, let’s analyze what a full-court press for Mars colonization looks like.


Robert Zubrin constantly beats the drum for exploring Mars first. It is disingenuous to say that the goal of space exploration is the colonization of Mars. Even colonization advocates would be happy with colonization of the Moon, the asteroids, and many other destinations. The discovery of life on Mars would not matter much one way or the other. Suppose there is Earth-like life on Mars. That might point to a common origin or a similar bootstrap method. What is that worth commercially? If you knew the answer, how much could you sell it for? Ten billion? What follow on activities would that news generate? None. Life may be an exciting discovery perhaps the most exciting in all history, but it does not amount to a large inducement to go to Mars.

Mars would be an excellent idea to get started if this were the only space colonization option. There is a much better option, however, teasing us as it hangs in the sky.

Mars is an excellent colonization spot and should be colonized because it is a great place to live. If we are going places as a species, we have to start somewhere. Right now, the level of space commitment by all actors on Earth is about $50 billion a year. This level of commitment would pay for about twenty Mars Direct-style missions every two years. This is a feasible budget for the colonization of Mars. Many technologies can be optimized if the focus of Earth space efforts was colonization. Cyclers could be placed in permanent Earth-Mars transfer orbit. In situ resource utilization could eliminate the need for hydrogen shipment from Earth. Better crew selection could eliminate the need for humans to take a return trip. If the goal of human presence on Mars is to colonize it, $50 billion a year can do it well.

It will probably take decades of subsidy before a Mars colony could sustain itself. A twenty-year program of $50-billion-a-year subsidies would hit a trillion dollars. This is an affordable sum for a rich planet. It would be an excellent idea to get started if this were the only space colonization option. There is a much better option, however, teasing us as it hangs in the sky.

The Moon

The Moon has many relative advantages. The first is capital utilization. A Lunar cycler can make hundreds of round trips in the time that a Mars cycler can make. Second, there is much less fuel required to get from the Earth to the Moon than to Mars. Existing technology can be used to get to the Moon (see “Soyuz to the Moon?”, The Space Review, August 2, 2004). A lunar landing mission might cost $120 million for an Ariane 5 booster. If each mission cost another $120 million for the Soyuz, service module and everything else, then that would be $240 million per flight instead of $5 billion per flight. That means that a $50-billion level of commitment from Earth can afford over 400 flights every two years. Of course, that level of commitment could be optimally spent in much better ways. By creating a lunar cycler, a station at L-1, an orbital fuel depot, in situ utilization of lunar oxygen and possibly lunar water, there could be a vibrant community on the Moon.

While a single Ariane 5 could not heft as much as a Mars Direct flight, it may still transfer a comparable amount of resources and people as a Mars Direct flight would to Mars. Since life support and consumables are much less onerous for a short trip than a long trip, there is a lower mass requirement for crew transfer flights to the Moon and much less depreciation of capital in transit. Having new heavy lift that would enable Mars Direct would also enable more sensible lunar colonization missions.

There are many supporting reasons to go to the Moon. Consider three categories of justification: engineering, economics, and politics.


First, on a mission to the Moon, Earth rescue is a decent possibility for certain kinds of failures. On a trip to Mars, this would be out of the question. As NASA is finding out with its shuttle return to flight efforts, having a standby rescue ship and a space station to go to makes failure recovery for many failures feasible without too much increased capability from our existing hardware.

Second, the proximity to Earth allows for just-in-time planning. With Earth only a few days away, a regular resupply mission can have last minute changes to its manifest. That means that fewer spares need to be kept on hand to assure the same level of safety as in a Mars mission.

Third, the short distance between the Earth and the Moon allow Earth based teleoperation to be a viable alternative to robotics and local human operation. This vastly leverages the capability of capital equipment on the Moon.

If we are colonizing both Mars and the Moon, colonizing the Moon first would help inform the colonization plan of Mars. The reverse would not be as true because Mars colonization would take longer.

Fourth, there is valuable information that can be learned in setting up a space colony that will raise the likelihood of success of all future colonization efforts. So if we are colonizing both Mars and the Moon, colonizing the Moon first would help inform the colonization plan of Mars. The reverse would not be as true because Mars colonization would take longer.

Finally, resource and energy options are opened up to guard against our energy appetite increasing (as our nuclear appetite isn’t) or carbon appetite decreasing. In addition to lunar resource utilization, creating an option to colonize near Earth asteroids is very interesting and makes many resource extraction strategies feasible even if it would take technology breakthroughs or huge changes in the economy to make them financially viable.


The Moon offers a near-term self-sufficiency without any technological breakthroughs. The tourism industry can potentially provide a high-end alternative to orbital tourism (see “Space elevator dry run: next stop, the Moon”, The Space Review, this issue). Patrick Collins makes a good case that cheap orbital access can enable a vibrant lunar tourism industry. With a heavy subsidy, the Moon may become a cheaper destination for a long stay than even an orbital hotel. That is, lunar in situ resource utilization can potentially make oxygen, water, and structural materials less expensive on the Moon than in orbit.

Since the Moon is a more exotic and varied destination than orbit, it will likely rate a higher level of demand than orbit. Thus a vibrant tourism industry could result in a strong lunar economy that does not need to be subsidized as early as 2030. There could be a faster development to Antarctic level of commerce (13,000 tourists a year) or Alaska level of commerce (population 600,000). There would still need to be imports from Earth, but every nation on Earth has imports, so becoming self-sufficient in all commodities is not a necessary condition for the success of a colony.

In addition to tourism, the Moon could export video entertainment to the Earth. Lunar sports might make great television. Lunar trampoline, diving, and gymnastics should be very interesting to watch and would likely bring in ratings higher than similar events on Earth. Lunar dance rates to be extraordinary. A lunar movie studio may also make some great exports to the Earth.

The Moon also offers a great spot for astronomical observation. This allows the reclaiming of terrestrial radio frequencies currently used for that purpose. There are also new Earth observation possibilities.

Space skills will be valuable and firms and people with experience on the Moon will be well able to help develop cislunar and martian systems. Radiation management experience, artificial gravity creation technology, operation and maintenance, flywheel, maglev, and mass driver technologies are all likely to be developed on the Moon and useful in future efforts.

There could be a huge wave of private investment that is coincident with government colonization efforts.

Labor-saving technologies are likely to give a boost to the terrestrial economy. The fine details of how this will affect us is hard to predict, but if the cost of labor on the Moon is high because of the high cost of transportation, new and varied uses of teleoperation and robotics will become cost effective. Some of those technologies will have immediate application on Earth. The less scripted and higher intensity nature of lunar development will allow these to emerge more quickly from lunar than martian colonization.

To sum up, the lunar economy can pay for all its imports through the tourism industry, intellectual property exports, science, entertainment, space skills, low-g skills and labor saving technology.

There could be a huge wave of private investment that is coincident with government colonization efforts. That could result in a co-development of many industries such as terrestrial point-to-point rocket service, orbital tourism, teleoperation, and robotics.

Economic opportunities of a more long shot nature are also worth adding to the calculus. Turning the Moon into a TV (see “Buy the light of the Moon”, The Space Review, August 30, 2004) is exciting. A testbed for space elevator deployment would be nice, too.


The Moon may become a very exciting destination with a substantial GDP. Being there first means that the high ground is already occupied for any future militarization of the Moon.

It’s possible that colonizing the Moon will help muster the political will to colonize Mars. Earthers will be able to see the colony directly with their own eyes. A convincing existence proof will be there for everyone to see that colonization is feasible and profitable.

A lunar colony is a politically feasible off-Earth gene bank increasing the chances that the species will be immortal. The act of leaving the cradle may be the other addition to our chances for immortality.

It will be harder to monopolize communication between the Earth and Moon than Earth and Mars. This will create a free flow of ideas that will benefit both societies. There will be a greater spirit of freedom sooner with lunar colonization due to speedier development, and the faster mixing of ideas.

Colonizing the Moon will also be a faster spur to legal development. The development of space law, especially property rights, mineral rights, and to a lesser extent labor law and human rights will create additional liquidity for other space colonization activities.

The Moon may make a Mars colony feasible or desirable, thus enabling three branches of humanity.

Having independent space nations will enrich the solar system polity and make the solar system and the species more secure from natural disaster. We can speed interstellar exploration and colonization. Ultimately we may create two new worlds that are every bit as rich, varied and interesting as our own.


The Moon is a very interesting destination in its own right. Being closer to the Earth creates engineering, economic, and political opportunities. The Moon may make a Mars colony feasible or desirable, thus enabling three branches of humanity. A lunar colony can use much more mass imported from Earth and more flexible and capable engineering. Tourism may independently justify lunar colonization, but science, technology, skills and entertainment make the case stronger. Having a new place to live with new laws, customs, and ideas may ultimately be the most valuable contribution of all.