Space entrepreneurs laid out a lot of the details for their billionaire-backed plan to extract resources from near-Earth asteroids today, but other details — such as how much they've received in investments, or exactly how they'll get their hands on precious water and precious metals — are still being held close to the vest.

If Planetary Resources is as successful as its founders hope, it could be bringing a fortune in platinum and gold back to Earth within the next decade or two, and supplying outer-space filling stations with water, fuel and air for interplanetary travelers. The company could tap into trillions of dollars' worth of space resources. But the venture could also go bust, just as some of the first European trading companies did when they came to the Americas centuries ago.

"There's a significant probability that we may fail," company co-chairman Eric Anderson acknowledged during today's big reveal at Seattle's Museum of Flight.

At least two things are certain: Planetary Resources is already bringing in income, and it's intending to launch real hardware within two years. "This company is not about paper studies. .... We're not just talking about it. We've done enough of that," Anderson said.

The company was founded in 2009 by Anderson and Peter Diamandis, but flew under the radar until last week. Both men have had long experience with space and technology ventures: Anderson heads Space Adventures, the company that has brokered eight private-passenger trips to the International Space Station. He also serves as president of Intentional Software, the company founded by billionaire space traveler Charles Simonyi. Diamandis is co-founder of the X Prize Foundation (which awarded a $10 million spaceflight prize in 2004), Zero G Corp. (which puts passengers on zero-gravity airplane flights) and the Rocket Racing League (which is currently in neutral).

Stephen Brashear / Getty Images

Planetary Resources' president and chief engineer, Chris Lewicki, shows off a full-scale mockup of the Arkyd Series 100 space telescope during a news conference at Seattle's Museum of Flight. "Good morning, everyone. I'm Chris Lewicki, and I'm an asteroid miner," he told the crowd.

This latest venture has the backing of Simonyi as well as other billionaires, ranging from Google's Larry Page and Eric Schmidt to Silicon Valley's Ram Shriram and Texas' Ross Perot Jr. (son of the former third-party presidential candidate). The company's advisers include filmmaker/adventurer James Cameron and astronaut/scientist Tom Jones.

Planetary Resources

An informational graphic explains Planetary Resources' perspective on a future "gold rush." Click on the image for a larger version.

Planetary Resources' executives declined to say how much the backers were putting into the business, but Diamandis touted them as "risk-tolerant investors" who were prepared to support the venture for decades. He also said "the company is cash-flow positive at this point," with about 20 engineers working at the company's headquarters in Bellevue, Wash. And there are still more openings to fill, which is a big reason why the company's executives decided to go public now.

Former Mars mission manager Chris Lewicki, who serves as the company's president and chief engineer, said the company had a contract with NASA to share data about the development a laser-equipped spacecraft system that combined imaging, optical communications and navigation. He hinted that there were other contracts as well, but wouldn't provide details.

Step 1: Launch space telescopes
The system will be used on Planetary Resources' first-generation spacecraft, the Arkyd Series 100 space telescope, also known as Leo. As Lewicki told me in a previous interview, the Arkyd Series 100 will serve as the company's Earth-orbiting survey telescope for identifying asteroids. It will also be sold to other parties for use as a "personal space telescope" or Earth-imaging satellite. He said the price tag for the telescope would be on the order of tens of millions of dollars, and eventually mere millions of dollars.

The Leo telescope would be built to have "multi-tool or Swiss Army knife capability," Lewicki said. Its imager would be capable of doing spectral analysis of near-Earth asteroids, to determine their chemical composition. There'd also be a camera mounted on a boom so it could take pictures of itself. The Museum of Flight's president, Doug King, said he and his institutional colleagues might someday consider becoming customers.

With a mass of 66 to 110 pounds (30 to 50 kilograms), the spacecraft would be small enough to launch as a secondary "rideshare" payload on any of a variety of launch vehicles, including the SpaceX Falcon, the Russian Dnepr or the European Ariane. The first launch is expected within two years, Anderson said.

Planetary Resources' prime targets would be among the estimated 1,500 asteroids that are energetically easier to get to than the moon. The team would be looking for water-rich or metal-rich asteroids that come close enough to Earth for a more detailed survey to be made. 

Step 2: Go beyond Earth orbit
The asteroid survey effort would continue with the Arkyd Series 200 "Interceptor," which would be equipped with a propulsion system and scientific instruments as well as an imager. Such craft could be placed into geosynchronous Earth orbit as a secondary payload — then identify, track and fly past asteroids that happen to come between Earth and the moon. Lewicki told me that the interceptor craft could get "up-close and personal" with a near-Earth asteroid within five years.

Planetary Resources

An artist's conception shows the Arkyd Series 200 spacecraft tracking an asteroid.

Planetary Resources

A swarm of Arkyd Series 300 spacecraft conducts reconnaissance on an asteroid.

Step 3: Swarm around an asteroid
The Arkyd Series 300 "Rendezvous Prospector" spacecraft would incorporate the laser-based communication system, enabling a swarm of probes to surround a distant asteroid for coordinated reconnaissance. "Within a decade, we hope to have identified our first target that we'll start extracting resources from," Diamandis told me. The Series 300 would demonstrate technologies that could be used for interplanetary missions by NASA or other entities.

Lewicki said the mission plan called for sending multiple low-cost spacecraft so that the failure of one probe wouldn't doom the mission. "When failure is not an option, success gets really expensive," he quipped.

Step 4: Get the goods
Later generations of spacecraft would have the capability to extract water from carbonaceous asteroids. If there's power available for a space processing system, the water could be broken down into hydrogen for rocket fuel and oxygen for breathable air. Such materials could be stockpiled in orbital or deep-space fuel depots, to be fed to spacecraft in need of a fill-up. Diamandis said a 165-foot-wide (50-meter-wide) asteroid with 20 percent water ice content could provide enough hydrogen and oxygen to power every space shuttle that ever blasted off.

The first goal for resource extraction would probably be a water-bearing asteroid, Diamandis told me, but eventually techniques would be developed for extracting gold and platinum-group metals from promising asteroids and returning the shipments to Earth. Platinum-group metals are particularly valued because they're used in a wide variety of high-tech devices, ranging from consumer electronics to fuel cells for electric vehicles. Platinum currently goes for more than $1,500 an ounce, which makes it almost as costly as gold.

If those valuable metals could be brought back from space at an affordable price, that could create a multitrillion-dollar shift in high-tech markets.

Hurdles to overcome
That's a big "if." In order for Step 4 to succeed, there'd have to be sufficient demand for deep-space refueling. Right now, there's zero demand, but that could change if NASA actually goes through with its current plan to send astronauts to a near-Earth asteroid by the mid-2020s and to Mars and its moons by the mid-2030s.

Planetary Resources' long-term business plan assumes that in the next few decades, there'll be enough spaceship traffic to recover its investment in asteroid-mining infrastructure. The precise shape of that infrastructure is yet to be determined: One illustration provided by Planetary Resources shows swarms of spacecraft doing strip mining, while another shows a water-bearing asteroid being enveloped by a huge inflatable shell.

One option might be to capture a small asteroid and bring it closer to Earth for processing. This month, a study prepared for the Keck Institute for Space Studies at Caltech determined it would be feasible to capture a 500-ton, 23-foot-wide (7-meter-wide) asteroid and transport it to a lunar-scale orbit. Mission cost was estimated at $2.6 billion, which is about the same cost as NASA's Mars Science Laboratory mission. The members of the study group included Lewicki and Jones as well as John Lewis, who has been studying the prospects for asteroid mining for decades and is serving as an adviser to Planetary Resources.

Mining a 23-foot-wide asteroid won't produce as much of a payoff as the 165-foot-wide asteroid that Diamandis had in mind, but the bigger the asteroid, the more difficult it would be to bring it closer to Earth. There might also be risks associated with moving space rocks or even platinum shipments around our planet's celestial neighborhood.

"The energy equivalent of a medium-sized 'ore wagon' in space, if it fell to Earth, would be on the order of a hydrogen bomb," NBC space analyst James Oberg said in an email. (That might be an exaggeration. The fireball that blazed over California and Nevada early Sunday is thought to have been caused by a meteor about the size of a minivan, with the energy equivalent of 3.8 kilotons of TNT. That's roughly a quarter of the explosive power of the Hiroshima atom bomb.)

"Carl Sagan long ago warned that building asteroid-deflecting technologies had a dark side — the same technology could be used to steer asteroids directly at Earth for military threats," Oberg wrote. "Fortunately, Sagan's fears were science-based and not spaceflight operationally based. It turns out to take far too long — years in flight — to actually drop a space rock on Earth. And the ability to deflect space objects safely away from Earth, or into commercial mining zones, is nowhere near accurate enough to do the opposite — aim for Earth itself.

"But the issue is a perfect rallying cry for environmental activists who can be counted on to rally against this looting of heaven's virginal treasures."

If Planetary Resources' long-term plan is successful, that could force nations to face the long-dormant issue of property rights in outer space. Oberg said widescale commercial exploitation of space resources could spark a diplomatic outcry, "at least until the United Nations gets some acknowledged 'tax' on any space-based profits." That issue is at least a decade away, however.

Even if Planetary Resources doesn't hit its long-term goal, the earlier phases of its business plan — the data deals and the spacecraft sales — would still give the billionaires an opportunity to recoup their investment. And it's virtually certain that other companies will eventually join the fray. For example, a venture called Moon Express is chasing after a share of the $30 million Google Lunar X Prize and making plans for mining operations on the moon. Just today, Moon Express announced the expansion of its scientific advisory board.

"We don't believe you have to wait around for a date with a near-Earth object," Bob Richards, the venture's co-founder and CEO, told me in an email. "If you want to mine asteroids, go to the moon  —  they have been bombarding the moon for billions of years."

How would you rate the chances for Planetary Resources, Moon Express and other would-be extraterrestrial miners? Feel free to cast your vote and/or leave a comment.

More about space resources:

• Asteroid mining venture starts with space telescopes
• Google billionaires back space resource venture
• Could legal loophole lead to extraterrestrial land claims?
• Private property in outer space? It's debatable
• To infinity and beyond: Investing in space travel
• How to make the moon pay

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.