Virgin Galactic said last month that it hoped to begin suborbital space tourism operations in the second half of this year, depending on the progress the company makes on test flights and on the FAA's licensing process.
While awaiting an FAA commercial operator's license, the company has to move the operation and vehicles from Mojave, Calif., to New Mexico, where it will prepare to fly a few preservice flights to test customer experience.
Virgin Galactic, which has been taking reservations for the flights for the past eight years, said it has signed up about 680 customers — or "future astronauts," as the company describes them.
At present, a ticket for a flight aboard SpaceShipTwo costs $250,000, but Virgin Galactic said it hoped to be able to reduce the price to $100,000 in the next decade.
"Ultimately, the more customers we fly, the more affordable the pricing will become," said a Virgin Galactic spokesman.
Virgin Galactic and its Spaceship Co. subsidiary have 370 employees. The companies have ramped up manufacturing spacecraft in anticipation of the start of passenger operations.
The company said it is at an advanced stage in its flight-test program and it hopes to do full spaceflight tests this spring.
During its most recent powered flight, SpaceShipTwo reached a planned altitude of 70,000 feet, a little over 13 miles.
Ultimately, it will soar to an altitude of 68 miles in its commercial flights.
SpaceShipTwo hitches a ride on WhiteKnightTwo, a mother ship that carries it to an altitude of 46,000 to 47,000 feet, then releases the spaceship portion and returns to the space port.
SpaceShipTwo employs a hybrid rocket engine that launches it from the WhiteKnightTwo vertically at supersonic speed, hitting a maximum velocity of Mach 3.5. (For comparison, the supersonic Concorde hit speeds of Mach 2.04 or 1,354 mph).
The SpaceShipTwo rocket burns for 55 seconds, after which the spaceship's six passengers experience several minutes of weightlessness, floating freely in the cabin.
SpaceShipTwo has been designed to coast upward to a maximum altitude of 68 miles.
During ascent, passengers will experience gravitational forces of up to 3.5 Gs (3.5 times the gravitational pull on a body at the surface of the Earth).
When SpaceShipTwo prepares to return to Earth, its two pilots will maneuver the spaceship to give passengers the best possible view of the planet.
For re-entry, passengers will be seated in a reclined position for gravitational forces that will reach about 6 Gs.
At about 70,000 feet, SpaceShipTwo will slow to subsonic velocity and begin gliding to its landing 25 to 40 minutes later.
The FAA has stipulated that Virgin Galactic passengers must be at least 18.
The company will provide first-time customers with training on a centrifuge that simulates the accelerations and G forces they will experience during flight.
NASA astronauts have to be at their peak levels of mental and physical fitness, but that is less due to the rigors of spaceflight than to the need to operated complex equipment.
SpaceShipTwo "will be much friendlier to the average potential astronaut," the Virgin Galactic spokesman said.
Virgin Galactic is owned by Richard Branson's Virgin Group and Abu Dhabi-based Aabar Investments.
The first space module and mother ship were built by Scaled Composites. In the future, both SpaceShipTwo and WhiteKnightTwo will be built by Virgin Galactic's Space Co. subsidiary.
The luxury travel consortium Virtuoso has an exclusive relationship in the Americas with Virgin Galactic.
Virtuoso's Accredited Space Agents have sold more than $10 million worth of seats on Virgin Galactic, which claims to be holding more than $80 million in deposits for its passenger space flights.
The suborbital trips will launch from Spaceport America, in Las Cruces, N.M., a new facility funded by the New Mexico Spaceport Authority with money raised for the purpose through a voter-approved sales tax.
Branson said that he has been interested in space flight since the 1969 moon landing but that the idea for Virgin Galactic took more solid shape in the late 1990s, in part as a result of conversations he had with Buzz Aldrin, the second person to walk on the moon.
Follow Kate Rice on Twitter @krtravelweekly.