Extra-terrestrial resource use is key to human expansion through the cosmos

Human space exploration is projected to expand to long-term or permanent habitation of the Moon, Mars, and beyond. If the goal of human planetary exploration is always to return to Earth (like NASA's Apollo missions to the Moon) then limited exploration to use local planetary resources, such as asteroids for rocket propellant manufacture, may aid a future Apollo-style program. Presently, such a constrained engineering effort, capped by an end date, seems to miss some aspects of the human spirit.

However, if our goal is to build a permanent, expanding, and self-sustaining extra-terrestrial civilization, then a myriad of clever uses must be made of planetary resources. A new solar-system economy must be based on resource occurrence and accessibility, where options for ore extraction, transport, and manufacturing are favorable and economically beneficial.^1–6 The industrial base of a civilization on the Moon or Mars would rely on raw materials from rocks (see Figure 1), ice, and the air.⁶ Space-based solar power could supply Earth with energy derived from structures manufactured partially from asteroids.⁵ Additionally, asteroids and the Moon could supply rocket fuel for the new solar-system economy.¹

The first step in this approach is the identification of resources on Mars, asteroids, and the Moon with coordinated robotic orbital reconnaissance, surface forays, and subsurface assays. Local and remote robotic analysis of areas with colonizing potential must incorporate advanced onboard data processing, positive feature detection, the quantification of material properties, intelligent autonomous decision making, a flexible capacity to reorder exploration priorities, and effective human-robot interaction.⁷ A scheme based on fuzzy autonomous cognition and decision making has been proposed for astrobiological exploration,⁸ and it is also required for resource exploration.

Planetary resource exploration will place more emphasis than ever on intelligent robot systems. As resource exploration moves to exploitation, robotic sensors working in tandem with robust physical manipulation will place increased emphasis on automation in effective quarrying, tunneling, boring and ore extraction. Similar robotic approaches are being developed for the mining of undersea resources on Earth.

A new interplanetary global economy will have to assess the benefits of resource identification and utilization against a comprehensive cost-benefit analysis for human health and safety, considering environmental impacts, future habitability and sustainability, and other human priorities in the development and growth of civilization.

Figure 1. NASA's Opportunity rover explored potential Mars resources. Left: Light-toned mud-cracked rock (∼ 0.6m or 2 feet across) is composed of magnesium-calcium-iron-sodium-potassium-rich sulfates and minor chlorides and silica-rich material. Middle: color enhancement shows compositional details. Right: Color-enhanced panorama shows a thin layer of hematite granules (potential iron ore) overlying salt-rich rocks.

A coordinated and comprehensive program of resource exploration of the inner solar system can be assisted by astronauts, but a cost-effective approach necessitates automated, intelligent robots. National space agencies should coordinate plans, share technologies for automation, and agree to release and share analysis of planetary data on a timely basis.

The control of our ability to remake or destroy worlds must become a topic of international discussion and agreement. Considering the likely increase in international competition for access to space resources coupled with a lack of any regulatory order, the runaway use of intelligent robotic systems and their short-sighted implementation, even with technical success, may permanently devastate our planet and others. It makes no sense to rove from one planet to another in a wave of resource use and depletion like interplanetary locusts.

Hence, with robotic systems, concepts of sustainability are vital. The ultimate intelligence test for humans may be in the capacity to “just say no” at the appropriate time and in the right circumstances. If we do not tackle the sustainability issue for planet Earth⁹ there is little hope that we will do so for other planets, and little hope that civilization can maintain the necessary economic capacity to sustain for the long reach to the stars.

Enthusiasm for planetary exploration and technology development must be balanced to benefit society equally on Earth. Our expansion to the Moon, Mars, and beyond the inner solar system should be rooted in sustainability, and incorporate from the start a strategy to move beyond the exponential curves of population growth, increasing per capita consumption, and global resource depletion. More complete use must be made of nonrenewable resources on Earth now, and when we move outward from Earth. This will require the thorough mapping and assay of potential primary and secondary minerals and the byproducts of their ores on Earth, the Moon, Mars, and asteroids.