A U.S. company's plan to mine asteroids in space could open the door to a modern-day cosmic gold rush, as well as deep-space exploration and cosmic construction.

Deep Space Industries announced this week its intention to launch tiny spacecraft on prospecting missions to nearby asteroids by 2015. The laptop-sized FireFly spacecraft would search for raw materials such as precious metals, and even trapped gases that could be turned into rocket fuel.

Those exploratory missions would then pave the way for larger DragonFly ships in 2016 which would collect materials from asteroids before returning to Earth to analyze the samples.

Finally, under the third phase of the company's plan, a Harvester spacecraft would blast off with the ability to collect hundreds of tonnes of materials from asteroids.

Randy Attwood, senior editor of SpaceRef.ca, said entrepreneurs are eager to capitalize on what could represent a modern-day cosmic Klondike – the region of Canada’s Yukon that attracted tens of thousands of amateur gold-seekers in the late 1800s after large amounts of gold were discovered in Bonanza Creek.

"The asteroid belt is the 21st century, 22nd century gold rush. These are raw materials in space that could be potentially mined," he told CTV's Canada AM.

In addition to precious metals such as gold and platinum, it's possible that asteroids contain semi-precious metals such as nickel, which the entrepreneurs believe could be used to build future structures in space to house human colonies, communication satellites or solar electrical generating plants.

"If you're going to build in space in future, you want to tap into the natural resources that are already there, not bring the material up from Earth because it's too expensive," Attwood said.

Deep Space Industries is the second company in the past year to unveil plans for a space-mining venture. Planetary Resources, a company founded by aerospace entrepreneurs and backed by filmmaker James Cameron and Google executive chairman Eric Schmidt, announced intentions last spring for a similar venture.

In addition to mining asteroids for resources, Planetary Resources hopes to establish a cosmic fuel station by 2020 which could create rocket fuel from liquid hydrogen and liquid oxygen trapped in asteroids. The thought is that such a station could then refill spaceships on their way to Mars or other far-flung destinations.

According to Atwood, the first company that can establish a mobile filling station to refuel satellites -- which tend to only break down when they run out of fuel -- stands to make billions.

"I think these are space entrepreneurs, people who have some money, who have these ideas and are tired of waiting for the government agencies to do this because NASA's not going to do this, none of the agencies have the money, so they're going to do it themselves."

Attwood said the companies' plans are within the realm of possibility. So-called near-Earth asteroids could be reached within weeks or months, and most of the technology needed to carry out the proposed missions already exists.

The question, he said, is whether the entrepreneurs can secure the deep-pocketed investors needed to fund their cosmic dreams -- especially when the potential payoff is so far down the road.

"It's a great investment for you, but maybe your children or grandchildren will see a profit," Attwood said.