The idea of mining asteroids is definitely in vogue. In the past few years commercial space advocates have been pursuing new private-sector space business activities. Profiting from orbital operations is not a new idea. Commercial space activities started in the early 1960s, with the launch of the first geosynchronous communications satellites.

Many thought these early commercial space ventures were just the beginning of a vast array of other commercially viable space applications. Literally hundreds, if not thousands, of potentially profitable concepts have been tested in the financial markets, but few have gotten beyond the drawing board.

Today, some 50 years after the first commercial space success, we can point to only a few sustained and successful private sector space operations. Surprisingly, geostationary communications satellite services remain as the largest commercial benefactor of the natural space environment.

Today, we appear to be on the threshold of a new generation of space adventurers. Virgin Galactic and other entrepreneurs may soon regularly fly tourists on suborbital flights to the vacuum of space for the several-minute-thrill of being in "zero-G" free-fall. Others aspire to send vacationers into low-earth-orbit. Still others hope to soon send humans on a "free-return" trip to Mars.

As recently as last Friday, the Wall Street Journal published an opinion piece on, "Mining Asteroids and Exploiting the New Space Economy" in which Dean Larson, of the Planetary Society, argues for the passage of the American Space Technology for Exploring Resource Opportunities In Deep Space (Asteroids) Act. This bill, introduced in the House last month by Bill Posey and Derek Kilmer, applies only to asteroids and assigns the ownership of mined resources to "the entity that obtained such resources."

The Asteroids Act also protects the exploiting company's operations from "harmful interference." From a legal point of view, ownership and protection from interference are essential in order to realistically pursue mining anywhere, including outer space.

As it turns out, there already is a legal foundation for how we use outer space. Article I of the 1967 Outer Space Treaty says, "The exploration and use of outer space, including the moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development, and shall be the province of all mankind."

It further addresses the freedom of exploration and use of space, "Outer space, including the moon and other celestial bodies, shall be free for exploration and use by all States without discrimination of any kind, on a basis of equality and in accordance with international law, and there shall be free access to all areas of celestial bodies."

Article VI addresses government oversight: "The activities of non-governmental entities in outer space, including the Moon and other celestial bodies, shall require authorization and continuing supervision by the appropriate State Party to the Treaty." One might conclude that the Asteroids Act represents the fulfillment of the 1967 treaty obligation to supervise asteroid entrepreneurs.

All this is well and good. Discussions regarding the legal aspects of asteroid mining are obviously necessary in order to clear the way for commercial mining activities. Most will agree that asteroids have some value, they are plentiful, and they are free of any financial encumbrances.

For the sake of argument, let's assume the legal obstacles are non-existent and all potential asteroid mining organizations have a clear and free license to proceed.

Once mined, there would be a supply of basic minerals and other compounds made available for in-space development of infrastructure for extra-terrestrial exploration, exploitation and colonization. One might ask, "How do I convert basic materials into infrastructure?"

On Earth, we can make the conversion through the use of factories and equipment that are already available. In space, no such facilities now exist. So, the obvious question is, "Does it make more sense to mine asteroids and build factories in space than to continue the present system of using terrestrial resources and factories for the exploitation of the solar system?"

On a cost comparison basis, there is one element that is common to both options: The high cost of space access. As long as launching things remains expensive, further commercial exploitation of space will face large financial hurdles. When space access becomes affordable to all, there will be a variety of exploitation options, including both terrestrial and extra-terrestrial mining approaches.