Commercial space travel is close - really close. Or, at least, that's how it felt for onlookers who watched another successful test flight by Virgin Galactic's SpaceShipTwo rocket plane on Friday.

After more than three years of testing, the spaceship succesfully demonstrated its "Cold-Flow" procedure in which oxidizer flowed through the propulsion system and out through the nozzle at the rear of the vehicle, according to a press release.

Not only did the display affirm to those present of the nearness of their goal of commercial space flight, but it offered a view as well of what SpaceShipTwo will look like once in flight, according to Virgin Galactic's CEO and President George Whitesides.

Virgin Group's founder Richard Branson wrote on his blog that the flight "is a key milestone in our progress towards commercial space flight."

Once complete, SpaceShipTwo will be powered by a unique hybrid rocket motor with a twin fuselage and central payload area configuration to allow it easy access to its launch platform WhiteKnightTwo as well as room for both passengers and crew. Furthermore, it uses the same feather configuration that so easily allowed SpaceShipOne to re-enter the atmosphere.

Since it's launch in 2005, Virgin Galactic has received over 500 bookings, which can either be done through a $20,000 deposit or a $200,000 upfront payment, the latter of which is almost sold out, according to the site. Those looking for a more private experience can also purchase a private flight for six for $1 million.

Benefits besides traveling through space include invitations to events held at Branson's private island in the Carribean and game reserve in South Africa, chalet in the Swiss Alps and estate in the Atlas Mountains in Morrocco. Training on the company's centrifuge in Philadelphia and on zero gravity parabolic flights throughout the United States is also available. 

Tickets can be booked either directly through the site or through Accredited Space Agents, available here.