Integrated cryogenic helium system for extended duration balloon flights

Abstract

An integrated cryogenic helium system (ICHS) has been designed and constructed. The system is capable of providing helium replenishment for diffusion/leakage losses, trajectory control, and scientific instrument cooling. ICHS is also capable of providing temperature control for itself. The onboard control system permits typical flight control from pre-programmed modules and still allows manual override and emergency control to be sent via telemetry. Operational and control state data is transmitted to ground based monitoring and flight control systems. The ICHS system has application to both long duration balloon flight as well as shorter flights requiring trajectory control through float altitude manipulation. The initial system was produced in a 500 l liquid capacity, however it is easily scalable. A 500 l system represents about 65,000 m 3 of helium gas at 500 Pa pressure altitude, equivalent to about 370 kg of lift. Considering the total system weight, this provides greater than 1.9 to 1 advantage over conventional ballast. Allowing for dewar jettison the advantage improves to greater than 2.8 to 1.