The Los Angeles Times reports that an explosion at the Mojave airport killed three workers and injured three others, during a test of the propellant flow system for SpaceShipTwo.

In 2004, SpaceShipOne became the first privately funded manned spacecraft, and won the Ansari X Prize.  SpaceShipTwo has not yet been unveiled, but is being developed as a joint venture between Scaled Composites and Virgin Galactic, and is expected to be used for the first private passenger-carrying suborbital space flight.