Reflections after 50 Years of Space
A protege of Wernher von Braun, Jesco von Puttkamer has spent his long career working in human spaceflight. In this long essay, von Puttkamer gives his perspective on humanity's next steps into the universe. Here he discusses the prospects for Mars exploration.
To come back to today's frequently asked question: When will we be ready, after the current phase of research conducted with robotic probes and teleoperation, for the exploration of Mars by humans? In our current planning, in the framework of the space exploration program supported by President Barack Obama, we could launch the first expedition to Mars around the middle of the third decade, i.e., about 2035.
And will humans actually be able to live on Mars? History shows that our species has expanded mainly because it knew how to access and utilize local resources (today’s Greenland being one example). After securing their immediate survival, the first Mars pioneers will, for a long time, consider it their most important task to reduce their umbilical cord from Earth, i.e., the expensive resupply pipeline, to a minimum. Local mineral mining, resource processing, refinement, production, etc., are feasible but will require new technology developments already being considered today but not yet studied in any design detail. At least the extraction of oxygen and other essential gases will be considerably simpler on Mars than on the Moon: They can be obtained from Mars' atmosphere, water ice deposits and possibly liquid water, while on the airless Moon they would have to be extracted laboriously from mineral compounds in the lunar dirt.
However, a life "in the open" as we know it is not possible on Mars. Its atmospheric conditions require humans in the open to wear protective suits with personal life-support equipment. On the other hand, the planet has all the resources necessary for life and for establishing a new offshoot of human civilization. In that, it stands out drastically from all non-terrestrial bodies in our solar system, even from our own Moon. Unlike on the latter, on Mars the elements carbon, nitrogen, hydrogen and oxygen, as mentioned, can be directly obtained -- from the atmosphere, from the water ice of the polar caps, from the subsurface layer of tundra-ish permafrost and from liquid water if it indeed exists. The Red Planet also possesses deposits of many industrially interesting elements like copper, sulphur, phosphorus, etc., possibly concentrated in consolidated mineral pockets and veins, thus facilitating mining. The reason is that during the formation of the planet, unlike on the Moon, hydrologic and volcanic processes were involved, which would have enabled differentiation, stratification and sedimentation of the individual elements corresponding to their density and other characteristics.
Because the Martian atmosphere has no protective ozone (O3) layer, ultraviolet (UV) radiation is strong on the surface, but the atmosphere, thin as it is, is dense enough in the lowlands to shield vegetation against solar eruptions. Thus, surface crops would require only thin-walled inflatable greenhouses with protective domes of UV-resistant plastics. The interior heat generated in them by the greenhouse effect will be highly welcome on cold Mars. Smaller domes up to perhaps 50 m diameter should be lightweight enough to be imported from Earth; larger ones can be manufactured later from indigenous materials. Thus humans, after having at first been restricted to protective habitats on or below the surface, will at some future time be able to live and work in the open under huge plastic domes providing UV protection and air for breathing.
Beyond that, in the more distant future, one can also envision a radical ecosynthetic transformation of Mars' environment to approximate terrestrial conditions to some extent. Such processes, known collectively (from science fiction) as "terraforming," are already today being studied speculatively. "Planet engineering" on a global scale has in many respects already become terrestrial reality, even if unintentionally, as witness the human-caused climatic changes on Earth. On Mars the climate could be made more Earth-like by an artificially induced global warming, thereby causing "outgassing" of surface materials and partial melting of the vast polar water-ice quantities for a "wetter" atmosphere and the growth of terrestrial organisms. However, this would take a very long time, perhaps 500 to 1000 years and more. In addition, it poses the ethical problem of potentially damaging indigenous biota: Such modification of extraterrestrial environments by ecosynthesis must never be undertaken as long as it hasn't been established beyond doubt that the planet harbors no native organisms of its own, for which terraforming could amount to global genocide.
One way or another, Mars can become a real home for a branch of terrestrial civilization, not just an outpost for scientific research as the Moon. Taking as an example the history of the North-American continent, its discovery, settlement and development to today's USA and Canada and projecting from there (with considerable extrapolation) the disproportionately larger development of Mars, it would appear plausible that even with increasing reduction of the umbilical resupply pipeline from Earth, it will take many generations until the new civilization has grown large, diverse and productive enough to become reasonably independent of Earth, i.e., autonomous. This means, there would be decades, even centuries of vibrant trade relations between Mars and Earth: Mars importing specialized high-tech products, luxury goods, and materials not available locally, and exporting goods of its own, such as deuterium (heavy water, apparently five times more abundant on Mars than on Earth) as fuel for nuclear fusion power plants, or ideas, inventions, and innovations which usually sprout much fresher in pioneer societies as demonstrated by 19th Century America vis-à-vis the "Old World". With this, an unstoppable development would be set in motion which over very long time periods could lead eventually to the distant day when not just one world inhabited by humans will orbit the Sun, but two of them.
Next: Wrapping it all up.