Devangshu Datta: Mines in the sky
It could cost $2.6 bn just to develop technologies for mining and transporting metals from space back to the earth
The key problem of space exploration is encapsulated in one factoid. In space, caviare is much cheaper than bread. Fish eggs have higher calorific value. Lifting 1 kg out of the earth’s gravity well to a Lagrange point (a place where the earth’s and the moon’s gravities cancel each other out) costs $100,000.
To make asteroid mining work, as Planetary Resources intends, the Seattle-based start-up will have to solve the cost-mass conundrum before it can even think to tackle other formidable challenges. Many technologies will have to be conceptualised from scratch.
The management has credibility, inasmuch as anybody does. One co-chairperson, Peter Diamandis, thought up the X-Prize, which drove private spacecraft design. The other co-chairperson, Eric Anderson, managed Nasa’s Mars mission. Investors include Larry Page, Eric Schmidt, James Cameron and Ross Perot Junior.
Planetary Resources will first chart asteroids with near-earth orbits, using its Arkyd-100 space telescopes. Then, it will use swarms of spacecraft (Arkyd 200s) for detailed mapping. The survey and mapping stages won’t cost more than $100 million or so.
After confirmed strikes, robots will be used to mine fuel and other commodities. That’s when it gets expensive. The Keck Institute of Space Studies estimates that it could cost $2.6 billion just to develop the technologies for mining and transporting metals back to the earth.
Most asteroids – rocks of various shapes and sizes – are in orbits between Mars and Jupiter. Some, like Ceres (radius of about 490 km), are large enough to be dwarf planets. Others are much smaller (1 km or less). Spectrum analysis indicates many of these rocks contain large deposits of base metals, water ice, carbon compounds and precious metals.
Over 7,000 asteroids have near-earth orbits. Some approach closer than the moon. If water-ice is mined on some of these and transported to Lagrange points, that would be a big step. Low gravity could make it much more efficient to lug ice from an asteroid than from the earth’s surface. Water is a rocket propellant, when split into its constituent hydrogen and oxygen. Gravitational cancellation at Lagrange points allows fuel depots, and facilities for constructing robots to be established at those.
Once fuel depots are set up, metals can be mined. Getting metals down to the earth will also present problems. Efficient heat-shields and good guidance mechanisms will be required to avoid dropping man-made meteors on population centres.
There are grey areas in the law. The 1967 Outer Space Treaty, which was adopted by the United Nations General Assembly, says, “Outer space, including the moon and other celestial bodies, is not subject to national appropriation.” Can individuals and private corporations appropriate and exploit such bodies? By analogy, mining occurs in international waters.
The treaty does clarify that exploration and use of outer space shall be “free of restraint and discrimination, and that there will be free access to all parts of space”. Satellite property rights and rights to orbits assigned by the International Telecommunications Unions are recognised. The $350-billion commercial satellite industry depends on this.
Planetary Resources may generate revenues from space tourism, fuel supply, satellite rentals, optical communications technology, robotics, and so on, long before it sells its first platinum. The R&D efforts will, in themselves, throw up serendipitous breakthroughs with impacts on other industries. As with the East India Company, or Columbus, the consequences could be far-reaching and totally unpredictable.
In fiction, human beings have been fascinated by asteroids ever since Professor Moriarty wrote his path-breaking On the Dynamics of an Asteroid. Science fiction writers like Antoine de St Exupery, Larry Niven, Frederik Pohl, Orson Scott Card, Norman Spinrad and Robert Heinlein have all made a living from these rocks. So have the creators of games like Halo, Eve Online and Terminus. In the next two decades, we’ll see some versions of those dreams turn to reality.