credit: Virgin Galactic / caption:
Go here to find the test logs for Rocket Motor Two develoment, the hybrid solid rocket motor that will send SpaceShip Two above 100km (62miles)
No information on the fuel or oxidiser type is given although there is an indication that the fuel was changed after hot fire one. The test logs are fairly bland although some introductory text at the top of the webpage gives some interesting background
Many subscale hot-firings were performed at Scaled Composites between Jun 05 and April 09 to evaluate several different fuels, igniters, injectors, insulators and nozzle configurations, as well as other components and parameters. Based on the results of those subscale firings, the Scaled/SNC team chose a full-scale rocket motor system design and began testing in April, 2009.