Piezoelectric actuators are known as a compact and dynamic solution for space laser pointing applications. Yet, to avoid the use of an HDRM (Hold Down Release Mechanism), the usual maximum load force needs to be increased, which impacts directly on the stroke performances of the actuator. Additionally, the cryogenic environment has a significant impact on the piezoelectric components, mechanical part and integrated sensor performance, especially on strain gauges that present an advantage in compacity and precision but that cannot operate under low temperatures.
The ESA funded the De-SPIN Project to address those challenges by designing and testing an actuator based on Amplified Piezoelectric Actuator (APA®) technologies that integrate new features to ensure the cryogenic compatibility, low magnetism and vibration resistance once integrated in a complete Fast Steering Mirror. This actuator can reach a 105μm stroke at -150°C with redundancy and can withstand an 18.04 g-RMS random vibration launch with a 0.125kg payload.