apparently they had never tested this rocket before using this type of fuel. they haven't been flying as of late because they were switching from a rubber-based fuel to a plastic-based fuel.
this flight was the test flight.
http://www.popularmechanics.com/science ... ck=pm_news
the pilot died from branson's hubris. test shit before you put humans on it you f**k
http://www.popularmechanics.com/science ... ck=pm_news