The National Scientific Balloon Facility (NSBF) conducts scientific balloon flights. Scientific payloads ranging from a few hundred up to several thousand pounds suspended weight are flown over the southern United States. People living in these areas are subject to risk from these operations. A model has been developed to predict the risk associated with the ascent phase of a balloon operation. This model includes all of the significant factors that affect ascent phase risk. The model is automated in a computer program whose input contains all of the parameters and factors for a particular mission. The results of this model can be used to advise management personnel of the risk level for a particular balloon mission. This model can be used as a long range planning tool or on the day of launch to determine whether the mission risk level is acceptable. / Master of Science