The settlement of Mars is a long-term goal of many space advocates, but is it something that should be a near-term goal of agencies and companies? (credit: Mars One) Mars is awful

As rumor would have it, the incoming Trump Administration signals the imminent demise of NASA’s “Journey to Mars.” If there’s truth to that, it’s a circumstance the space community should welcome. Sending humans to Mars is not the right way to allocate resources at this time, and maybe not at any time, for reasons I’ll elaborate shortly. While Mars as a destination deserves criticism, the very idea of sending humans to space at all will require vigorous defense in the coming period of uncertainty. It really doesn’t matter that Mars is (by some measures) the most Earth-like planet in the solar system. It’s not Earth-like in any way that makes it meaningfully easier to survive. A question was recently posed to me: Why should we colonize Mars when we aren’t even trying to live on Antarctica or the bottom of the ocean? I’m a firm believer that we shouldn’t keep all our eggs in one basket, but this simple question undeniably reveals that certain wild-eyed plans about Mars are half-baked. Of the many plausible doomsday scenarios that could befall the Earth, how likely is it to leave nowhere left that’s at least as habitable as the Antarctic? Not very. So why is it that every futurist seems to have Mars at the tip of their tongue, and not Antarctica? One big reason is that a cornerstone of reducing existential risk is closed-system life support of the kind that’s used in space. The ISS represents the most progress made on this front to date, but there’s more to be done. A fully self-sufficient habitat would be essential to surviving many types of Earth-bound disaster, just as much as it would be essential to have a closed habitat for any solar system destination you might choose. You just shouldn’t choose Mars. Mars is awful. It really doesn’t matter that Mars is (by some measures) the most Earth-like planet in the solar system. It’s not Earth-like in any way that makes it meaningfully easier to survive. There’s no partial credit on this. Beyond simply lacking in oxygen, Mars’ atmosphere is swirling with dust that bears actively poisonous perchlorates. One rationale for Mars is In-situ Resource Utilization (ISRU). The particular opportunity for utilization that’s most commonly cited is to collect carbon dioxide from the Martian atmosphere. Carbon dioxide can be split to obtain breathable oxygen, though it’s not the most limiting consumable. The element that atmosphere processors on the ISS most routinely need to have replenished from an outside source is hydrogen. In combination with hydrogen, carbon dioxide can also be made into methane rocket fuel. It might be said that the best use for Mars is making fuel to leave Mars. That, in and of itself, is not a compelling reason at all to start a colony. It becomes even worse when recognizing that there are far better places from which to obtain methane. The most common type of asteroid in the solar system is the carbonaceous chondrite, so named because it’s full of carbon. Significant amounts of carbon dioxide and methane can be present on these bodies, along with other useful volatiles like water and ammonia. While it’s technically feasible to export methane from Mars, it would be like exporting water from the desert. Focus on growing the economy, and that will enable the rest in due time. Think of the Moon and near-Earth asteroids as a proving ground not for Mars but for other moons and more distant asteroids. Another major factor working against Mars is gravity. It’s one of the hardest places in the solar system to land safely. Although its surface gravity is less than Earth’s, Mars is unique in the solar system for being as massive as it is without having enough of an atmosphere for useful aerodynamics. The Curiosity rover was near the upper bound for the ratio of vehicle mass to the heat shield’s aerodynamic drag. There’s a reason NASA called the landing process the “Seven Minutes of Terror.” Larger vehicles, including any crewed lander or bulk supplies, would need rocket thrust to shed orbital momentum throughout the descent. It can be done, but at a considerable risk compared to a more practical habitat in orbit. Gravity is also a problem when getting back off of Mars. Successful habitation in space can only happen in the long term with the help of a space economy, which isn’t grown by passively receiving care packages from Earth. The goal is to displace things that have to be launched with alternatives that are already in space. On small bodies in the solar system, one could move material to orbit in bulk using a relatively tiny rocket, or even no rocket at all. Methods like space elevators, skyhooks, or railguns would drastically reduce the need for propellant. Reaching orbit in these ways from Earth strains the limits of engineering and sanity, but they would be feasible around asteroids. Any resources acquired from Mars would be at a cost disadvantage compared to asteroids. Of course, some people will still strongly believe in the value of Mars for scientific curiosity and national prestige. Hopefully they can recognize that the mission will have much better prospects for success if backed by the technology and resources of an asteroid economy. Terraforming, if it’s not a complete fantasy, would require that infrastructure to exist and be devoted to the terraforming project for centuries before seeing results. It’s premature at this point for terraforming to guide our thinking at all. Focus on growing the economy, and that will enable the rest in due time. Think of the Moon and near-Earth asteroids as a proving ground not for Mars but for other moons and more distant asteroids. Those who advocate for these alternative space efforts must still make the case to those who wonder why to bother at all. The first reason that should interest these skeptics is that the technologies developed for human survival in space can improve lives on Earth. The space program to date has built an impressive portfolio of spinoff technologies, and there’s every reason to believe that process would continue in the course of addressing the health effects of long-term space habitation. Research on microgravity-induced bone demineralization lends insights into osteoporosis. Radiation is a much more pressing health hazard in deep space than on Earth, but strategies for mitigating its effects can be relevant on the ground. Methods of growing food in space would need to be more compact, reliable, and resource efficient than we’re used to. Relevant advances in hydroponics, aquaculture, and bioreactors would be immediately useful in Earth’s less hospitable regions. One might ask why these should be spinoffs, rather than research programs on their own, but an economy in space should also be of great interest to the Earthbound. The most valuable import from space is likely to be beamed microwave power. It would be a source of carbon-free electricity more abundant and reliable than any terrestrial renewables. We’re not just talking about a lower power bill, rather a major shift of humanity’s position on the Kardashev scale of civilization development. I don’t think we can predict where that will lead any more than people two decades ago could have predicted the potential of smartphones. To deploy that kind of space-based power at scale will require enough of an industrial base to manufacture solar panels in space. That’s the goal to bear in mind. On the way to achieving that capability, there will be mining and services aimed at refueling and maintaining satellites. United Launch Alliance’s Cislunar 1000 concept, referring to a projected 1,000 people working in space in 30 years, is an example of how that might work. It would extend the useful lifetimes of satellites that have all sorts of Earth-oriented applications. The critical steps are not in getting to Mars but simply living isolated from Earth. It’s clear that investing in space technology can benefit life as we know it in myriad ways, but the most important consideration still remains the possible end of life as we know it. Although truly existential threats are outliers even among black swan events, the risk is not zero. We can’t act as if we have hundreds of years to spare. At the point we know the exact nature of a threat, it may be too late to prepare a response from scratch. ULA estimates 30 years to implement its Cislunar 1000 plan, and that’s just a prelude to the kinds of infrastructure we’ll need to avert or weather the worst disasters. There’s a chicken-and-egg problem to the space economy, in that its rate of growth depends on how much business is already in space. Just like ISS resupply stimulated a new generation of rockets to meet the demand, future deep-space endeavors by NASA and others will accelerate the next steps towards privately-funded Earth independence. Those seeds must be sown now in order to ensure they sprout in the future. The critical steps, though, are not in getting to Mars but simply living isolated from Earth. Home









