WHEN THE FIRST OCCUPANTS boarded the International Space Station on November 2, there was none of the excitement or awe that marked the heady days of Gemini or Apollo. The station is being touted as man's first step toward a continual presence in space, but who cares? Didn't the Russians already accomplish this with the Mir? And what's the point of putting more humans in earth-orbit, especially when it's accompanied by a price tag of more than sixty billion dollars?

While NASA hails the prospect of scientific breakthroughs flowing from ISS, researchers are skeptical. Few believe that the station's scientific value will ever justify its astounding cost -- much of which is due to the need to haul into orbit every gram of material used to build the station and keep it running.

The station will weigh some 900,000 pounds when it is finally completed in 2006, resulting in launch costs alone of about ten billion dollars, and that doesn't even account for astronauts, food, fuel, supplies or additional research equipment.

But suppose we didn't have to carry everything up there? What if we used the station to learn how to process resources from space itself? It may sound far-fetched, but this could be the most profound and significant payoff to result from ISS, allowing us to build future stations, research facilities, factories and living quarters at a fraction of the cost of space enterprises today.

THE IDEA OF MINING the resources of space is an old one, first dreamed up by science fiction writers in the 1960s, who envisioned vast industrial complexes arising from the desolate voids of the Moon and Mars. But what to them looked like fantasy --constructing habitats from moondust or making rocket fuel from icy asteroids -- now appears to be fact.

"To say that space exploration, by its very nature, must cost billions and billions of dollars is to ignore the growing body of research in recent years that shows that space can be economically viable," declares University of Arizona professor John S. Lewis, the godfather of research in this field. "By using space to our advantage, we can not only make future exploration affordable, we can make it profitable."

It is a bold statement, but one that is attracting an ever-increasing corps of believers. Where NASA portrays space as a harsh, barren wasteland that must be conquered with untold bravery and endless funds, Lewis and other scientists are coming more and more to recognize that space is a gold mine -- literally. The Moon, asteroids, and the outer planets offer an endless supply of materials that could be harvested to our purposes, including hydrogen and oxygen for rocket fuel; iron, zinc, and copper for construction; precious metals for fuel cells and industry; and, perhaps most significant, water to sustain life.

Without an inexpensive and abundant supply of these ingredients, space will never be more than a rich nation's lark. At current launch prices, a day's worth of water for the four-person crew costs more than 300,000 dollars. And while recycling helps to defray some of this cost, the annual ISS water supply is still estimated at tens of millions of dollars. Even if a new generation of launch vehicles eventually cuts that cost by a factor of ten, it still would not be enough to make large space enterprises -- like orbiting factories or the building of a lunar base -- cost effective.

"If we want to go to space, space has to pay," urges Lewis, adding that government-driven projects like ISS serve only to confuse the public about the potential value of space endeavors. "People look at the space station and all they see are sunk costs," he said dejectedly. "We have to get them to see the benefits, too."

When Lewis himself stares into the cosmos, he sees a path to the future, a time when Earth's energy problems disappear and the living standards of people around the world are equalized -- all because of space's infinite resources. He divides the raw materials in space into two categories: those that are rare, valuable, and being depleted on Earth, and those that are common on Earth, but too expensive to launch into orbit.

In the first category are gold and the platinum-group metals, which include platinum, palladium, iridium, osmium, rhodium, and ruthenium. These rare elements are in tremendous demand. They are essential to the miniature fuel cell technology that promises efficient, nonpolluting energy. They are also used widely in the electronics industry, for things like high-capacity disk drives and sophisticated capacitors, and as catalysts in pollution control devices.