Originally , the HEAT - 1X rocket was to be fuelled by paraffin wax .
A ground test 28 February 2010 revealed that some of the paraffin wax had only partially melted , instead of evaporating .
Originally , the HEAT - 1X rocket was to be fuelled by paraffin wax , but a ground test 28 February 2010 revealed that some of the paraffin wax had only partially melted , instead of evaporating .