Thermo-vacuum test chamber development for heat switch testing in simulated Martian conditions

Abstract

In the fall of 2014 the Institute of Aerospace Engineering had been awarded by contract to perform Miniaturized Heat Switch testing. The Miniaturized Heat Switch was the unique technology developed by Italian company Aero Sekur for European Space Agency's missions to Mars. The aim of the project was to develop an innovative but simple experimental thermo-vacuum test chamber to simulate Martian atmospheric conditions. Conditions such as vacuum of 50 Pa absolute, temperatures in the range from -125 degrees C to + 60 C and pure CO2 environment of 1000 Pa absolute. The vacuum tightness of the chamber, deep cooling of the specimen under vacuum environment, thermal insulations or heat transfer paths had to be precisely considered. Important decision was to use the liquid nitrogen as the most appropriate cooling medium and copper rods for heat transfer outside the chamber. Later, elementary calibration vacuum-tightness test of the facility showed that the pressure increased from initial value of 220 Pa absolute to 450 Pa absolute within 16.5 hours and thus proved excellent chamber design. Therefore in the future, the test chamber modular design can be easily modified to allow testing of other space equipment in different simulated conditions.In the fall of 2014 the Institute of Aerospace Engineering had been awarded by contract to perform Miniaturized Heat Switch testing. The Miniaturized Heat Switch was the unique technology developed by Italian company Aero Sekur for European Space Agency's missions to Mars. The aim of the project was to develop an innovative but simple experimental thermo-vacuum test chamber to simulate Martian atmospheric conditions. Conditions such as vacuum of 50 Pa absolute, temperatures in the range from -125 degrees C to + 60 C and pure CO2 environment of 1000 Pa absolute. The vacuum tightness of the chamber, deep cooling of the specimen under vacuum environment, thermal insulations or heat transfer paths had to be precisely considered. Important decision was to use the liquid nitrogen as the most appropriate cooling medium and copper rods for heat transfer outside the chamber. Later, elementary calibration vacuum-tightness test of the facility showed that the pressure increased from initial value of 220 Pa absolute to 450 Pa absolute within 16.5 hours and thus proved excellent chamber design. Therefore in the future, the test chamber modular design can be easily modified to allow testing of other space equipment in different simulated conditions.