MAJIS Shutter QM and FM Thermo-vacuum Test Report

Abstract

This test report provides a summary of the Thermo-Vacuum Test results on the QM and FM shutter units, a mechanical part of the spectrometer MAJIS (Moon And Jupiter Imaging Spectrometer), a payload instrument on board of the JUCE (JUpiter ICy moons Explorer) mission. The shutter actuator is composed by an electromagnetic brushless actuator mounted with an aluminium blade. The aims of the actuator are to maintain the blade in two stable positions (open and closed), to rotate the blade from one position to other in a time less than 300ms and a low power consumption. These tests have been conducted to demonstrate the capability of the shutter to operate according to requirements in vacuum at predefined temperature conditions. The target temperatures for the QM model are Top-Min = 100K and Top-Max = 165K and pressures less than 1 mbar. A total number of thermo-vacuum cycles of 42 are requested, including an extra hot point at 337K but only for the first cycle at the beginning. A slope of 2.7K/min has been agreed and planned for all the cycles. For the life test, performed only on the QM1, selected as reference, a total number of 1500 cycles at the same conditions of T and P are requested. For what concerns the test performed on the FM model, the target temperature is Top-Min = 105K and Top-Max = 160K. A total number of thermo-vacuum cycles of 4 are requested, including an extra hot point at 337K but only for the first cycle at the beginning. A slope of 2.7K/min has been agreed and planned for all the cycles.