Very high altitude tethered balloon parametric sensitivity study

Abstract

This paper describes a parametric study of a concept very high altitude (65 kft) tethered balloon system design. Critical design parameters are examined, and the sensitivity of balloon volume to these parameters is used to evaluate their impact on the overall design. The parameters examined are drag coefficient, downwind displacement, tether length, ground tether angle, free lift, payload, envelope and tether weight, and several environmental parameters. The study shows that all of the selected parameters have a significant impact on the balloon volume, but the operational wind profile is, by far, the most significant design driver. Another interesting finding is that reasonable changes in payload weight have only a small effect on balloon volume. Based on the results of the study, it is concluded that a practical very high altitude tethered balloon system is feasible with existing analytical and manufacturing technologies, but it will require design optimization and selection of mission parameters. (Author)