By Irene Mona Klotz
at Cape Canaveral, Florida
Sir Richard Branson's Virgin Galactic has collected $10m in deposits from people wanting a quick ride beyond Earth's atmosphere.
Virgin Galactic is offering the prospect of private space travel
Another 34,000 would-be astronauts have registered for rides aboard a commercial version of the experimental Ansari X Prize winner SpaceShipOne.
The cost to experience four to five minutes of weightlessness is about $200,000 (£113,242).
The project was threatened earlier this year by US export control regulations.
Last year, SpaceShipOne completed two sub-orbital spaceflights in a week to claim the $10m Ansari X-Prize.
Virgin Galactic is paying SpaceShipOne designer Burt Rutan's firm to build a fleet of five vessels for suborbital spaceflights. Test flights are on schedule to begin in 2007, with commercial operations to begin a year later.
"At the moment, we don't see any hurdles," said Virgin Galactic president Will Whitehorn.
Ship size expands
Since the project's announcement just before SpaceShipOne's prize-winning flight from Mojave, California, Sir Richard and Mr Rutan decided to expand the size of the follow-on commercial version of the vehicle, informally known as SpaceShipTwo.
A final design is scheduled to be announced before the end of the year. But the plan now is for each ship to be capable of carrying six or seven passengers and two pilots, said Mr Whitehorn, who was in Washington, DC this week for a series of meetings and speaking engagements.
"We're very happy with it," Mr Whitehorn said.
The spaceships will be about the size of a Gulfstream Five business jet and like SpaceShipOne, will piggyback a ride atop a larger airplane before its rocket engines ignite to travel beyond the atmosphere.
SpaceShipOne made three trips to suborbital space - defined as 100km (328,000 feet) - including a record-breaking lunge to 367,442 feet (112km) or 69.6 miles above the planet's surface.
Mr Rutan's firm plans to build two mother ships, each about the size of a 737, to carry SpaceShipTwo vehicles into the sky.
To give passengers a bit more thrill for their pricey rides, SpaceShipTwo may be carted a couple of hundred miles away from the take-off sites before being released for launch. That would enable riders to take in a more diverse view of Earth-in-the-round.
Most important, however, is to maximize the time during which passengers experience microgravity.
"When we asked people about what they wanted in a suborbital spaceflight the top three things were weightlessness, weightlessness and weightlessness," Mr Whitehorn said.
The seating compartments on SpaceShipTwo are being designed so that passengers can float around a bit while tethered to their seats.
Initially, Virgin Galactic plans for all flights to take off and land in the United States, Mr Whitehorn said. In addition to flying from the Mojave Airport, where Mr Rutan's firm is based, the company is looking at sites in New Mexico and Florida.
The project was threatened earlier this year by US export control regulations, which prohibited British participants from even looking at designs produced by Mr Rutan's firm, Scaled Composites.
Virgin Galactic however finally received a licence and that not only cleared the way for full participation in the project, but also enabled the firm to become a part-owner of a new venture, called The SpaceShip Company.
This firm plans to market and license SpaceShipTwo technology to other companies that want to buy the vehicles.
"We see this is a good precursor for the future as we expand into orbital flight," Mr Whitehorn said.