Fifty thousand feet over the California desert, the world is a vast expanse of blue with a drab carpet of khaki far, far below. Pilot Peter Siebold sets the craft's trim to 18 degrees, pushes the stick forward, and counts down: "Three. Two. One. Release."

The mother ship rises above us as we drift downward for a few seconds. Siebold pulls the yoke back and flips a toggle on the center console. Then: Bang! The hybrid rocket motor ignites and we're a missile shooting toward the stars at more than three times the speed of sound. The sky becomes black. Then it gets weirder: Siebold flicks the yoke and the vehicle whips around 180 degrees. We're still heading straight up, but the ship is flying backward. It's like looking out the windshield of a car that's floored in reverse, except my view is 1,500 miles in each direction, from the Sea of Cortez to San Francisco Bay.

My attention wanders for a split second and the verisimilitude evaporates — seeing walls and ceiling and my blue jeans jerks me back to reality. I'm not in the sky but in a hangar at the headquarters of Scaled Composites in Mojave, California, sitting in a flight simulator for the firm's latest spacecraft, SpaceShipTwo. If all goes well, SpaceShipTwo will be the commercial version of the radical rocket that won the $10 million X Prize in 2004 after it made two flights to the edge of space in a 14-day period. Richard Branson licensed the technology for Virgin Galactic, his space tourism gambit, which aims to start regular visits to the thermosphere by 2012.

After all of the prize money and media coverage, routine space tourism — this grand flight of human fancy — seems about to happen. SpaceShipTwo will be carried aloft by a mother ship, WhiteKnightTwo, which has been flying for nearly a year. The first SS2 is under construction and slated to begin flight tests in early 2010. Virgin has already sold $60 million in tickets to its first 300 passengers. And a taxpayer-funded spaceport is under construction near Las Cruces, New Mexico.

In a year, maybe two — barring any test-flight glitches — people who have the right financial stuff will be rocketing daily into space for a few minutes of sensory overload and ego gratification. It may not be the colonization of Mars, but as Siebold says, "did the Wright brothers have Boeing 747s in their consciousness when they flew at Kitty Hawk? No, but it just grows from here; what they achieved made that possible." If Virgin and Scaled Composites succeed in making this huge technical leap, a trip to suborbital space will have been reduced to nothing more than a pricey Tilt-A-Whirl for grown-ups.

If you spend enough time around the Scaled Composites hangars, it all begins to sound routine, almost banal — just another project for a company that churns out innovative aircraft the way Dyson turns out innovative vacuum cleaners. Ask the team about the technical challenges it has faced assembling these ships and the answer surprises you. "Um, really," Scaled Composites president Doug Shane says, "it's not much of a technical job at all." It's a statement that Virgin's would-be competitors, all years away from putting a commercial system in place, wish they could agree with. And it downplays the biggest challenge of all: How do you take a dangerous and radical one-off prototype and turn it into an everyday vehicle?

In 1994, Microsoft cofounder Paul Allen asked Scaled Composites founder Burt Rutan a question: Would it be possible to beam down broadband Internet signals from high above Los Angeles using a plane that the legendary aeronautical engineer was designing? Back then, broadband was basically nonexistent, and Allen was looking to fill the gap. The plane, called Proteus, is a bizarre-looking aircraft capable of loitering at 60,000 feet for up to 14 hours, and it's been used for high-altitude research by everyone from NASA to universities.

While he was working on Proteus, Rutan remembers wondering, "What else could you use it for?" He has been captivated by space ever since he saw Wernher von Braun on Walt Disney's TV show in the 1950s. It occurred to Rutan that Proteus might be able to carry a smaller craft under its fuselage and "do a little point-and-shoot" toward the stars. That would eliminate one of the trickiest parts of rocket launching: the massive engines and fuel needed to lift a spacecraft through the lowest, thickest part of the atmosphere and onward into space. By the time Scaled Composites first flew Proteus in 1998, Rutan knew he could design and produce a mother ship capable of launching a 7,000-pound payload at 50,000 feet.

Over the next few years, Rutan used that knowledge to chase the $10 million X Prize, which had been announced in 1996. As he designed the aircraft, Rutan made a series of decisions that proved nothing short of genius and on which Virgin's plans ride today.

For one, he made the systems, components, and cockpits of the mother ship and spaceship identical, save for the rocket engine controls on the space ship. For example, SpaceShipOne's feathering actuator — the device that moves the wings into an upright position — was also used to operate the mother ship's landing gear; every test of the mother ship would test parts of the spaceship as well. As pilots learned to glide the mother ship to a landing from high altitude, they would be learning to land the spaceship, too, racking up copious flight hours long before they ever flew the spaceship for real.

SpaceShipTwo under construction in Mojave, California.

Photo: Adrian Gaut

Rutan's solution for the single most dangerous and technically challenging part of any spaceflight — reentry into the atmosphere — was equally creative. His so-called shuttlecock design pivots the wings of the spacecraft up for reentry. "The key is a low ballistic coefficient," Rutan says, referring to the ratio between weight and drag. "Think of the difference between a bullet and a feather." A streamlined bullet screams heavy and fast through the atmosphere — it has so little drag that it generates huge amounts of heat. A feather, on the other hand, has a lot of surface area, and it's so light that it floats slowly, lazily through the air. By building the wings of the lightweight carbon-fiber capsule so that they pivot into a 65-degree angle of attack, Rutan has a very light craft with a lot of drag and low aerodynamic loads — just like a feather. His spaceship can reenter the atmosphere safely, routinely, without the pilot ever having to touch the stick. Once the ship gets closer to the ground, the wings flatten out again for a gentle glide to the runway.

Although there were a couple of dozen competitors for the X Prize, in reality it was no contest — Rutan was solar systems ahead of everyone else. And though he made it look easy, even his own designers doubted that a small private company could blast a manned rocket to suborbital space. "I didn't think we'd see it through," Shane says. "It was just so far out of the realm of what any of us had done. It was radical."

When you see WhiteKnightTwo next to WhiteKnightOne, you realize what a leap Scaled Composites has made: It's like seeing a dragonfly next to a housefly. The new mother ship's wingspan is 140 feet, and it weighs 60,000 pounds. WhiteKnightOne weighs just 18,000. Bob Morgan, the plane's designer, takes me for a tour. In his blue jeans and polo shirt, Morgan comes across as an everyday guy — just another sharp mind turned loose by Rutan's dictate to think big and creatively, without fear.

We crawl around inside one of the twin fuselages of the mother ship and its spacious cockpit. It's the largest aircraft ever built completely from composite materials, all the way down to the carbon-fiber flight control cables that don't expand or contract in the extreme temperature changes of flight. With four turbine engines, it's light and powerful, able to operate almost 20,000 feet higher than commercial jetliners.

In 2004, the same year as the winning X Prize flights, Virgin licensed Rutan's technology and hired him to design the next generation of vehicles. To accommodate the sort of middle-aged rich people who can afford $200,000 for a flight (Brads and Angelinas, as Scaled Composites' engineers refer to them), the ships had to be bigger, safer, more stable, more robust. SpaceShipOne was a challenge to fly, with a tendency toward extreme rolling. In fact, pilot Mike Melvill could barely control it on his record-breaking flight. That wouldn't do for commercial space travel.

To reduce roll, the wings of SpaceShipTwo have been moved below the rocket motor. This enables pilots who aren't veteran test jockeys like Melvill to handle the craft. The systems are now more redundant, and the pilot is backed up by a copilot. "We're not really stretching the technology," Shane says, "so much as trying to make it safe and routine to fly day in and day out. That's not as sexy, but every bit as daunting."

Photo: Adrian Gaut

Virgin is also reimagining the aesthetics of a spacecraft. There's no cramped, utilitarian cockpit lined with hundreds of toggles and gauges. The fuselage of SpaceShipTwo is spacious — 7.5 feet in diameter — so there will be room for its six passengers to take off their seat belts and float around in zero g. There will likely be no barrier between pilots and passengers, and big round windows dot the ceiling and sides — more windows, it's fair to say, than have ever been on any spacecraft. The whole thing feels light and airy in a way that small aircraft never do — a considerable achievement that has not come cheap. "Winning the X Prize cost about $30 million," says Will Whitehorn, president of Virgin Galactic. "We're going to be spending about $400 million."

The tech is impressive, but the experience? As a proud cynic who has raised three kids in a house that didn't cost much more than a single Virgin Galactic flight, it'd be easy for me to be snarky about the whole thing. You can even imagine a passenger standing on the tarmac after the event, scratching his head with a bit of flier's remorse: "Did I just spend the annual salary of four teachers on that?" These days, you can buy weightlessness in 30-second bursts on zero-g parabolic flights at one-fortieth the cost.

But 300 people have already plunked down the full $200,000 price for their tickets. Several hundred more are "in the pipeline," a Virgin spokesperson says, and 82,000 have registered on the company's Web site. Space may be cold and empty, but the idea of blasting into it strapped into a rocket clearly gets people's blood pumping. Maybe it's the allure of new worlds, new experiences, the pull of the glittering stars in the night sky, the fascination with a journey to the final frontier fraught with danger and promise.

To create SpaceShipTwo, Burt Rutan translated the technical advances of SpaceShipOne into a craft designed for passenger comfort and everyday reliability.

Illustration: Dan Marsiglio

With typical Branson gusto for raw physical experience, Virgin is playing off those longings to sell a whole mini astronaut experience. Here's what the company wants you to imagine: The sun is high, the sky clear as only desert sky can be, the sleek and curving bubble of Spaceport America rising from the scrub, 45 miles from Las Cruces. On the flight line perches a crazy-looking twin-fuselaged aircraft cradling a spaceship — the three sharp noses call to mind its nickname: Triceratops. You're going to space, and you know it. You'll get a full mission profile briefing, a medical check, and a session in the simulator. Then you'll be strapped into a seat at the end of a long arm and spun in a centrifuge, subject to the three g's you'll experience sitting upright for takeoff and six g's you'll feel while lying down for reentry. You'll climb into the WhiteKnightTwo mother ship and fly to nearly 50,000 feet, learn to unbuckle and refasten your seat belts, and even make a few zero-g parabolic flights, all with your designated SpaceShipTwo pilots (who will suss out their passengers' physical and mental capacity to handle the experience).

Finally, the day of your flight arrives. Earth's curvature will just begin to be visible after a long, spiral climb attached to WhiteKnightTwo; above will be a crown of blackness. When the pilot releases the spacecraft, the mother ship will appear to rise above as you drop away. Six seconds after the rocket motor ignites, you'll be traveling at three times the speed of sound, perched on a high-energy Roman candle, hurtling into space, up there in the black void, subject to forces few humans have ever experienced.

As you approach the apogee of the flight, and for a few minutes after, you will simply be freed from gravity, falling through space. A touch of the thrusters orients the ship in whatever direction the pilot chooses — you'll be flying backward or sideways. You might notice the intense silence, since there's no noise in space and the craft won't be running any whirring, clanking mechanical parts. On reentry, you'll be able to hear the distinct pings of single molecules of helium and hydrogen hitting the carbon-fiber vessel as it begins to encounter the atmosphere.

Virgin is also pitching the idea that one day it will have spaceports spread around the globe, and that once you've seen Southern California you'll want to see the Arctic ice cap and the Arabian peninsula and smoky, chaotic Africa from 68 miles up. "Think of the aurora borealis!" crows Whitehorn. Don't underestimate how much people love to be tumbled around and made dizzy and scared out of their wits. Just ask Lauren McCollum, a 43-year-old real estate developer from Santa Monica, California, who signed on in 2005 and forked over her 200 grand on the spot. Along with 100 other early Virgin guinea pigs, she's already been through centrifuge training. "Six g's lying down wasn't bad," she says. "But the three g's through my head, well, I started to gray out a little! It was wonderful!"

Or B. J. Bjorklund. "I always wanted to be an astronaut!" says Bjorklund, a former Air Force pilot, who in 2005 saw Branson touting his newest scheme at the Experimental Aircraft Association AirVenture in Oshkosh, Wisconsin, introduced himself, and immediately pledged to take a flight. "I've been to all 50 states and 60 countries. I have that exploring gene in my body, and space is just on my bucket list!"

That Scaled Composites will soon have a passenger-carrying spaceship in the air seems pretty certain. And it's also clear that there are a lot of deep pockets itching for a ride. But that still leaves a lot of questions to be answered: Will there be enough demand to keep the five planned Virgin spaceships flying up to twice a day at maximum capacity for years to come? Virgin says yes, absolutely. Can the hybrid rocket motor fire routinely without issues? After all, no one has ever built a rocket that's been robust and simple enough to function daily. (The X-15 made 199 flights in the '50s and '60s, but the program cost $1.8 billion in 2009 dollars and killed one pilot.) Again, Virgin insists the answer is yes.

And even if it all works, will flying a bunch of tourists to the thermosphere 12 times a week make access to space cheaper and simpler for more serious pursuits? Will a carny ride get us to the moon? To Mars? To a new New World? Will it revolutionize transportation or science or satellite launches?

Virgin is betting that it will. In July, the company signed a $280 million deal with Abu Dhabi's Aabar Investments for a 32 percent stake in Virgin Galactic. The company is going to spend that money to find a way to use WhiteKnightTwo — or perhaps an even bigger successor — to launch rockets carrying small satellites in the 100- to 440-pound range into orbit. "We think there is a market for 100 launches a year, worth $300 million annually," says Virgin's Whitehorn. But this fleet of space-tourist-carrying rockets will serve another purpose: It will provide experience in how to operate a rocket routinely and safely. Virgin likes to use the analogy of commercial airplane flight after Charles Lindbergh crossed the Atlantic: A risky and exotic accomplishment suddenly expanded the horizon of what was possible, generating investment and rapid technological innovation.

Old-time rocketeers couldn't disagree more. The essential physics of Lindbergh's flight and a Pan Am Clipper a few years later are the same. But, they point out, the difference between sending SpaceShipTwo to an altitude of 68 miles and sending a satellite to low Earth orbit at 200 miles is staggering.

What Virgin is doing is significant, says John Logsdon, former director of the Space Policy Institute at George Washington University, "but it doesn't solve the technical problems that no one's been able to solve for 50 years — of low-cost, reliable, and reusable transport to orbit." And he has his doubts that Virgin will be able to attract many customers in the small satellite market. "It's an act of faith," he says, "like build it and they'll come." If anything, Logsdon points out, the gap between lifting tourists into suborbital space and launching meaningful payloads into orbit might stimulate the industry simply by showing how hard it still is to get satellites up there.

In the meantime, back at Scaled Composites, pilot Peter Siebold has been doing a lot of flying. "Look," he says, resetting the simulator for another go, "this is a hop before the leap. It's not that technically significant — going to the moon was — but we're putting all of this together into a package that allows the average person to experience spaceflight. This is where it starts!

Contributing editor Carl Hoffman (carl@carlhoffman.com) wrote about the Icon light sport airplane in issue 17.01.