The Scaled Composites/Virgin Galactic test program at Mojave is accelerating.
April 12 there was a 10.8-minute cold flow test in which the hybrid rocket motor was tested after SS2 was released from its mother ship, the WhiteKnightTwo.
Since March 11 there have been five WK2 test flights, which include two SS2 releases. Dec. 19 there was a 13.4-minute release-glide flight to test SS2 performance after several changes which included installing the rocket motor systems and nozzle; a new shortened aft skirt; and wing and strake thermal protection.
The hybrid rocket motor is a scaled up version of the one used to take SS1 to the edge of space, and win the Ansari $10 million X Prize with two such flights within a two week period, Oct. 4, 2004. The SS2 motor is rated at three times higher thrust than the original version. The liquid nitrous oxide oxidizer is sent through the hydroxyl terminated polybutadiene fuel. This configuration was selected for SS1 as safer than other candidate rocket motors. It is also being used for the Sierra Nevada Dream Chaser.
The cold flow test was the first time in the air that oxidizer was flowed through the propulsion system and out through the nozzle at the rear of the vehicle. As well as providing further qualifying evidence that the rocket system is flight ready, the test also provided a stunning spectacle due to the oxidizer contrail and for the first time gave a taste of what SpaceShipTwo will look like as it powers to space.
The upcoming first powered flight of SpaceShipTwo is in many ways the most significant milestone to date, being the first time that the spaceship has flown with all systems installed and fully operational. The speculation at Mojave Air & Space Port is that the first powered flight may take place within a few weeks.