Characteristics of Spaceborne Cooler Vibration Isolator using a Pseudoelastic Shape Memory Alloy

Spaceborne cooler generates undesirable micro-vibration disturbances during its on-orbit operation and this may seriously affect the image quality of high resolution observation satellites. For the aim of assuring the high quality images of the observation satellite, most of studies have dealt with on-orbit micro-vibration isolation system with a low stiffness, but have not taken launch vibration environments into account. Hence, holding-and-release mechanisms should be considered for guaranteeing the structural safety of the cooler supported by a low stiffness isolator and isolator itself during harsh launch loads. However, this approach has increased the system complexity and lowered its reliability, in addition to increasing the total mass of the system. To overcome this drawback, in this study, a blade type passive vibration isolator employing the characteristics of a pseudoelastic shape memory alloy (SMA) was proposed. This isolator can guarantee structural safety of the cooler and the isolator itself under harsh launch vibration loads without requiring holding-and-release mechanism, while effectively isolating the cooler-induced micro-vibration in on-orbit conditions. The basic characteristics of the isolator were evaluated through a dynamic loading tests in accordance with temperature variations. Based on the measured characteristics, the effectiveness of the isolator design under launch and on-orbit environments was investigated.