Publications

Head Impact from Falling Payload of a Small Balloon

Hovey, Chad B.; Terpsma, Ryan J.; Reyes, Ramon R.; Bowman, Daniel B.

Despite the increasing number of small scientific balloon missions with payloads in the gram-to- kilogram mass range, little is known about the injury risk they pose to humans on the ground. We investigated the risk of head injury using the head injury criterion (HIC) from impact with a 1.54 kg (3.40 pound) payload. Study parameters were impact speeds of 670, 1341, and 2012 cm s -1 (15, 30, and 45 mph) and protective padding wall thicknesses between zero and 10 cm (3.9 inch). Padding provided meaningful reductions of injury risk outcomes at all speeds. The maximum risk of AIS 3+ injury was approximately 3.6% (HIC 249) for the 670 cm s -1 (15 mph) case with 0.5 cm (0.2 inch) of padding, 34% (HIC 801) for the 1341 cm s -1 (30 mph) case with 3.0 cm (1.2 inch) of padding, and 67% (HIC 1147) for the 2012 cm s -1 (45 mph) case with 7.0 cm (2.8 inch) of padding. Adding 1.0 cm (0.39 inch) of padding to these two latter cases reduced AIS 3+ injury risk to approximately 13% (HIC 498) and 37% (HIC 835), respectively. Public safety can be increased when balloon operators use padded payload enclosures as adjuncts to parachutes. KFY TERMS: head injury criterion (HIC), expanded polystyrene padding, injury risk, balloons ACKNOWLEDGEMENTS We gratefully acknowledge the financial support of Sandia National Laboratories, Environment Safety & Health Planning, and John E. Myers, Safety Basis Engineer. We acknowledge Douglas Dederman for his participation in the R&A process.