Thermal Control System

Thermal Control System
System Kontroli Termicznej
Team responsible for conduction of thermal analyses in order to verify temperatures obtained on components during operation at low earth orbit. In space environment, heat transfer is very different from Earth. The main reason is marginal influence of convection which significantly complicates thermal balance at the satellite and can cause extreme temperatures. Depending on elements and orbit environment, the temperature range is estimated to be between -100°C and 100°C. Because of a much narrower temperature range at which electronic components can operate, thermal engineers are obligated to detect any incorrect configurations and to find the solution, which will allow the most important subsystems to stay within the permissible temperature levels during the whole satellite mission.

The main objective of TCS team in PW-Sat2 project is to perform thermal analyses in order to verify configuration of the satellite, proposed by mechanical team, and to find more optimal solution which will allow to obtain proper thermal balance for electronic and optical subsystems requirements. Due to harsh space environment, temperature limits and safety margins were introduced in order to survive in a hard to predict space conditions. Another objective of TCS is to design the heat management system, in a passive or active manner, which will allow to counteract extreme temperatures.

Currently, the team has conducted thermal test of the Structural Thermal Model (STM) by simulating conditions close to the orbit. To achieve it, a deep space simulator was used (by courtesy of Spacive company), which allowed to achieve -180°C environment, and Kapton heaters to imitate heat dissipation across electronic components and influence of solar flux across the structure walls.

Tests were performed at Space Research Centre Polish Academy of Sciences in a thermal vacuum chamber, where vacuum at the level of 10-8 mbar was achieved. Thanks to the tests, we have acquired a lot of important data about the temperature distribution across the prototype model which will allow to verify analyses performed so far.

The next step is to use the data from the mentioned tests and perform model correlation to obtain more precise and valuable results from the next analyses. If results will be still satisfying after correlation, the final configuration of the satellite will be accepted from thermal point of view.

Additionally, a bake-out procedure together with functional tests need to be performed for flight model in order to outgas all the surfaces and to verify the influence of higher temperature on negative performance of assembled subsystems.

Alan Budzyński

Thermal analyses of PW-Sat2 were done with the support of the ESATAN-TMS software:

Thermal tests of the satellite were supported by:


Space Research Centre of Polish Academy of Sciences