A FEASIBILITY STUDY ON ALTITUDE CONTROL SYSTEM DEVELOPMENT FOR RUBBER HIGH-ALTITUDE BALLOON

Abstract

Rubber weather balloons are low-cost, commercially available, capable of stratosphere flight, and commonly used for various purposes. With an ultimate objective of using rubber balloon to develop a controlled balloon system which satisfy operation requirements, it is necessary to obtain the performance requirements of altitude control system. This paper investigates the feasibility of altitude control system development for Helium-filled, spherical weather rubber balloons to satisfy specified operation requirements. Two different altitude control methods of adjusting buoyancy and adjusting weight are considered. Both methods use the technique of compressing gas into pressurized reservoir and releasing storing gas for altitude control. Theoretical derivations are used for assessing the performance requirements of the altitude control system. Simplified analysis for quasi-steady flights under design points (operation requirements) which include altitude change, heat transfer options (i.e. convection and radiation), vertical speed, and weather tolerance was made to obtain required initial Helium mass for the launch. Finally, the performance requirements of the altitude control system are analyzed based on all design points and initial Helium mass filled in the balloon. The results show feasibility of altitude control system with a large reservoir or with relaxation of operation requirements from both methods for the selected rubber balloon.