Challenges in the thermal analyses of the ascent and float phases of SUNRISE III

Date

2020-07-31

Journal Title

Journal ISSN

Volume Title

Publisher

2020 International Conference on Environmental Systems

Abstract

SUNRISE III consists on a Solar telescope which is going to be flown with a Long Duration Balloon. Being in the stratosphere, the thermal environment is very similar to that in space, and the heat transfer is mainly driven by radiation. However, some particularities such as the residence time, the geographical and seasonal variations, as well as the Solar Zenith Angle should be taken into account when defining the thermal environment based on real observation data. Typically, the analysis of the operational phase has been carried out through the analysis of two Steady-State cases based on the worst environmental conditions (hot and cold) to be found during the mission. In order to obtain these extreme cases, parametric analyses have been performed in order to consider not only the environment itself but also the influence of the thermo-optical properties and the orientation of the system. On the other hand, the ascent phase should be analysed separately due to the harsh environment to be found when passing through the cold layers of the atmosphere. In this case, the heat transfer is driven by convection and radiation and, depending on the conditions, the cold case of the mission could occur during the ascent. For the study here presented, the environmental parameters have been particularized to the launch site ESRANGE, in Sweden, and have been parametrized in order to quantify the influence of the launch time. To do so, the ascent phase analysis has been implemented in ESATAN-TMS, as is done for the float phase, in contrast to the traditional analytical studies. Challenges found when defining the environment and performing the analyses are presented together with the description of the SUNRISE III thermal model.

Description

David González-Bárcena, Universidad Politécnica de Madrid, ES
Isabel Pérez-Grande, Universidad Politécnica de Madrid, ES
Ángel Sanz-Andrés, Universidad Politécnica de Madrid, ES
Javier Piqueras-Carreño, Universidad Politécnica de Madrid, ES
Ignacio Torralbo, Universidad Politécnica de Madrid, ES
ICES109: Thermal Control of High Altitude Balloon Systems
The proceedings for the 2020 International Conference on Environmental Systems were published from July 31, 2020. The technical papers were not presented in person due to the inability to hold the event as scheduled in Lisbon, Portugal because of the COVID-19 global pandemic.

Keywords

ascent, thermal environment, Long Duration Balloon, float, ESATAN

Citation