The Federal Aviation Administration's Associate Administrator for Commercial Space Transportation (FAA/AST) has given license approval to Scaled Composites of Mojave, California, permitting the firm to expand flight testing of SpaceShipOne  -- a privately-financed rocket plane to carry passengers to suborbital altitude.

Rutan and his team of Scaled Composites engineers are vying for the $10 million X Prize purse. The competition is geared to advance routine suborbital passenger flight, as well as hasten the day of regular and, hopefully, low-cost orbital voyages of private citizens in the future.

SpaceShipOne's first powered flight, making use of a hybrid rocket motor, took place on Dec. 17, 2003. The piloted rocket plane broke through the sound barrier on the 100th anniversary of the Wright Brothers historic flight over Kitty Hawk, North Carolina.

The hybrid motor roared to life for 15 seconds, with longer burn times required to shoot to the X Prize prescribed suborbital altitude.

The craft has also undergone extensive glide flights, with several pilots at the controls. A last glide flight of the craft -- carried out on March 11 -- also featured a thermal protection system, suggesting that new powered flights are in the offing.

All test flights of SpaceShipOne have taken place over Mojave, California desert.

Last December it was formally announced that multi-billionaire Paul Allen -- the co-founder of Microsoft -- is footing the bill on the SpaceShipOne project.

Charles Kline, Jr., Special Assistant for FAA/AST External Affairs confirmed to SPACE.com that a launch license had been issued April 1: "We have issued a launch license ... to Burt Rutan and Scaled Composites."

AST's commercial space transportation licensing program is designed to ensure public health and safety through the licensing of commercial space launches and reentries, and the operation of launch sites.

Protection of public health and safety and the safety of property is the objective of AST's licensing and compliance monitoring/safety inspection processes.

The FAA/AST issues a license when it determines that an applicant's launch or reentry proposal or proposal to operate a launch site will not jeopardize public health and safety, safety of property, U.S. national security or foreign policy interests, or international obligations of the United States. FAA/AST does not license launches performed by and for U.S. government agencies.

Teams from around the world are vying for the X Prize. It will be awarded to the first team that privately finances, builds and launches a spaceship able to carry three people to 62.5 miles (100 kilometers) altitude, return safely to Earth, and then repeat the feat within two weeks.

The X Prize Foundation of St. Louis, Missouri, currently has funding to award a prize if a successful flight occurs by the end of 2004.

Work is also progressing on other X Prize contenders, such as Canada's da Vinci Project.

"We will be launching a manned flight sometime this summer. An announcement is coming up in the near future on the launch date," said Brian Feeney, team leader of the da Vinci Space Project, based in Scarborough (Toronto), Ontario. "Sorry, but can't be more specific at the moment," he told SPACE.com .