THERMAL PROBLEMS ASSOCIATED TO THE ASCENT PHASE OF STRATOSPHERIC BALLOON PAYLOADS. THE SUNRISE MISSION

SUNRISE is a solar telescope flown with a NASA LDB (Long Duration Balloon) stratospheric balloon. Its aim is to observe structures on the Sun with a resolution never previously achieved. The design of the thermal control of SUNRISE has been critical, for being the opto-mechanical devices as well as the electronics very sensitive to temperature. This work is focused on the thermal study of a generic payload carried by a long duration balloon during the ascent phase. A model taking into account convective and radiative thermal interactions has been set up. The payload’s temperature has been obtained as a function of the altitude from ground to floating conditions. The results have been correlated with measurements taken during SUNRISE test flight.