Status of the NASA continuing investigation of catastrophic balloon failures

Since the beginning of the 1980's, the USA National Aeronautics and Space Administration (NASA) Balloon Program has been besieged with a continuing problem of catastrophic balloon failures. In 1983 NASA conducted an investigation to identify possible causes for the failures and to determine the necessary corrective action(s) to prevent further occurrence of the problem. The investigation indicated the most probable cause of the failures was the balloon material. Subsequent corrective action(s) were taken to eliminate the problem by establishing a material acceptance criteria for balloon film. Although improvements have been noted in certain classes of balloons, the problem of catastrophic balloon failures continues. Efforts continue, to determine the cause(s) of the diminished performance of current balloons, including investigation of the microstructure of present and past balloon film, stress effects and simplified stress modeling including shape studies, and the equipment and procedures used in the manufacture of balloons. Most recently, a special team of experts has been assembled to aid in the investigation of the failure problems and the methods needed for a solution. The findings and status of the continuing investigation along with the future plans for the NASA program are presented.