WhiteKnightTwo, a four-engine jet-powered aircraft unveiled last year that features twin fuselages mounted on either side of a huge wing. Spaceship Two is in the middle.

Virgin Galactic’s Richard Branson unveiled his baby earlier this week; the first vehicle designed to carry commercial passengers into space. Dubbed “Spaceship Two,” the craft was designed by Burt Ruttan, winner of the $10 million X-Prize, whose Spaceship I soared 62 miles above the earth back in 2004.

Test flights will begin early next year, and if the government signs off on its safety, flights carrying paying passengers could begin as early as 2011.

Wanna take a ride? It will cost you $200,000 and you’ve got to get in line. Branson has signed up 300 passengers already.

Spaceship Two

Most of those ticket holders, along with California Gov. Arnold Schwarzenegger and New Mexico Gov. Bill Richardson, were on hand for the SpaceShipTwo unveiling Monday at Mojave airport, braving rain, high winds and frigid temperatures to witness the long-awaited rollout.

Branson told the enthusiastic crowd that safety was Virgin Galactic’s No. 1 priority and that “we will not be putting anybody into space until the test pilots have done many, many, many trips on this spaceship.”

“Only when we are absolutely certain we can safely to to space will we go into space,” he said. “I promise you, it will be well and truly tested before we go into space.”

Schwarzenegger said attending the unveiling was “one of the coolest things I’ve ever done.” Describing Branson as “an extraordinary visionary,” he called Rutan “one of the greatest space engineers of our time.”

Branson may be a great salesman but how safe is “safe?” Spaceship Two will be the first in a long line of commercial ventures that will eventually make going into space routine. Until then, I’ve got just two words for the colorful Mr. Branson:

Krista McAuliffe.

True, a suborbital flight on a well-tested aircraft will not carry the same risks taken by McAuliffe and the crew of the Challenger. But ask Ruttan what can go wrong and the list he gives will be considerably longer than that of a commercial terrestrial airliner.

Here’s how Spaceship two will operate:

SpaceShipTwo will be carried aloft by a futuristic-looking mothercraft called WhiteKnightTwo, a four-engine jet-powered aircraft unveiled last year that features twin fuselages mounted on either side of a huge wing.

For the unveiling Monday, WhiteKnightTwo, with the rocket plane attached to the center of the wing, was rolled into view amid soaring music and floodlights.

SpaceShipTwo will be released at an altitude of 50,000 feet. A hybrid rocket motor burning solid propellant with nitrous oxide then will boost SpaceShipTwo onto a steep trajectory to an altitude of more than 62 miles.

The roomy cabin of SpaceShipTwo, about the same size as a large executive jet, features multiple portholes to give its passengers a spectacular view of Earth and space.

After about five minutes of weightlessness as the spaceplane arcs through the top of its ballistic trajectory, the rocket plane will fall back into the atmosphere, pivoting its wings upward in a “feathering” technique invented by Rutan to increase drag and ease the stress or re-entry. From there, the spacecraft will glide to a normal runway landing.

Ruttan says the vehicle is being built to safety standards that exceed those in NASA operations. Of this I have little doubt; NASA operates under the assumption that the shuttle will have a serious accident about once every 48 flights (some experts are even more pessimistic). That’s about once every 9-10 years at the shuttle’s current launch rate.

Although the number of Spaceship Two flights a year will be determined later, it will be considerably more than the 5 or 6 shuttle launches a year. So while safety standards may be vastly improved, there is still going to be a significant risk due to the increased number of flights - especially the first few years of operation.

Going into outer space - for the moment - is still a very risky proposition. For all intents and purposes, and for the foreseeable future, getting there will continue to be an experimental challenge. I agree that we must begin this great leap forward with the commercial exploitation of space. My worry is that some aspects - including safety - are being oversold. I have no doubt that Branson and Ruttan will do everything in their power to make Spaceship Two as safe as it can possibly be made. But if space travel has shown us anything, it is that our best laid plans, and all of our efforts, mean little when dealing with the forces of the cosmos arrayed against us in space.

Think of the early crossing of the Atlantic in the 15th and 16th centuries. Many ships were lost. But the technology and ship building skills improved dramatically because it was commercially viable to get to the New World. Those tiny ships Columbus sailed in to cross the Atlantic were replaced in 50 years by much sturdier and more sea worthy vessels. They in turn, gave way to more improved ships until crossing the Atlantic became routine and relatively safe.

I imagine something similar will happen with commercial space travel. There will be tragic accidents, no matter how hard the companies will try to avoid them. Some businesses will not survive. Others will learn from those mistakes and press forward. And not only will space travel become safer as we go along, but the cost per pound of lifting cargo and humans into orbit will also fall dramatically. The latter benefit will lead to a true revolution as these private space-faring concerns will move beyond tourism and begin the great enterprise of serious exploitation of space-based resources. That’s where this is leading. And it is possible that in my limited lifetime, that I will see that process well underway before I depart earth for more interesting climes.

I have no idea how long it will take. My gut tells me that the less the government is involved, the faster the pace of progress, although as long as there are private citizens going up, I would hope that there is some regulation that will set standards for a minimum amount of protection for passengers. And I imagine that some new branch of OSHA will oversee any space-based workforce as well. This is inevitable, but how it shakes out will play a large part in determining the technological innovations and entrepreneurial spirit that will infuse the industry.

Congratulations to Branson and Ruttan. I wish them - and their passengers - luck and success.