Asteroid Mining–Problems and Opportunities
Asteroid mining refers to exploiting raw materials from asteroids and other minor planets such as Near-Earth objects (NEO). The raw material such as Iron, Nickle etc. can be possibility used in space construction and Hydrogen and Oxygen can be possibly used to sustain lives of prospective astronauts on site. This has been called in-situ resource mobilization. As of now, it remains theortical and fictional only. The Near-Earth asteroids are considered likely candidates for early mining activity. In recent months, a plan has been announced by billionaire entrepreneurs to mine asteroids for their resources. The company is called Planetary Resources and its founders include film director and explorer James Cameron as well as Google's chief executive Larry Page and its executive chairman Eric Schmidt.
As per the plan, the company plans to create a fuel depot in space by 2020 by using water from asteroids, which could be broken down in space to liquid oxygen and liquid hydrogen for rocket fuel. From there, it could be shipped to Earth orbit for refuelling commercial satellites or spacecraft. However, as of now the plan has been looked with skeptism as it is not cost effective.
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.
1. The foremost problem of space mining is cost. For example, 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. So, the scientists will have to first solve the cost-mass conundrum before it can even think to tackle other formidable challenges. Many technologies will have to be conceptualised from scratch.
2. The second problem is appropriation of such resources if they come within reach of the Human beings. There is a 1967 Outer Space Treaty, which was adopted by the United Nations General Assembly. It says “Outer space, including the moon and other celestial bodies, is not subject to national appropriation.” So, the question is whether the individuals and private corporations appropriate and exploit such bodies? 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”.
3. 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. (ET)
1. 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.
2. 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.
3. 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.