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Point Ahead Mechanism for Deep Space Optical Communication Development of a New Piezo-Based Fine Steering Mirror
19 June 2023
The purpose of this paper is to present the development of a novel tip-tilt mechanism, with integrated optics, designed for the JPL Deep Space Optical Communication (DSOC) module of the upcoming Psyche mission (2022 launch). This paper presents the design, assembly and tests of the produced models. Regarding the design phase, an emphasis was put on the mirror calculations to ensure that the required flatness would be maintained after integration, and that the part would withstand the thermal/mechanical environment. The actual optical measurements performed after assembly are also presented. The qualification results for a new alpha-case removal process for titanium parts are presented. Tests results are especially interesting
regarding the temperature behavior of the mechanism, impact on the stroke, and strain gage sensor feedback.
ATLID Beam Steering Mechanism and derived new piezoelectric based devices for optical applications
19 June 2023
In Space & Defence (as well as in many others fields), there is a trend for miniaturisation in active optics requiring new actuators. Applications also often require the ability to withstand high vibrations and shocks levels, as well as vacuum
compatibility for space applications. A new generation of small and smart actuators such as piezoelectric (piezo) actuators, are resolving this trend, thanks to their capacity to offer high energy density and to support both extreme and various requirements. This paper first presents the BSM mechanism and its requirements, the technologies involved in
the design and the validation campaign results. Secondly, a derived XY piezoelectric positioning stage based on the same APA® and associated Strain Gage sensing technology is presented with its associated performances. Finally, a new piezoelectric motor based on the APA® technology, which allows the combination of long stroke while maintaining high
resolution positioning of optical elements, is presented with experimental performances.
ATLID BSA Beam steering assembly piezo tip tilt
19 June 2023
ATLID (ATmospheric LIDar) is one of the four instruments of EarthCARE satellite, it shall determine vertical profiles of cloud and aerosol physical parameters such as altitude, optical depth, backscatter ratio and depolarisation ratio. The BSA (Beam Steering Assembly), included in emission path, aims at deviating a pulsed high energy UV laser beam to compensate the pointing misalignment between the emission and reception paths of ATLID [1]. It requires a very high stability and high resolution.
Beam steering mirrors: from space applications to optronic applications
19 June 2023
Fast growing Laser and new optic applications drive more and more needs for beam steering mirrors (BSM) and Fast Steering Mirror (FSM). For space optic instruments, CEDRAT TECHNOLOGIES has developed for 20 years several piezoelectric tip-tilt mechanisms. Presented recent examples include the ATLID BSA small tit tilt for quasi static nano pointing and MEFISTO, a large tit tilt for fast micro positioning. These space mechanisms perform high precision functions while being compact, lightweight and resistant to external vibrations and shocks. As shown in the paper, these advantages allow these technologies addressing several needs for other optronic applications than space, such as active stabilisation, micro scanning, disturbance compensation in IR imagers or telescopes.
Large Stroke Fast Steering Mirror for Space Free-Space Optical communication
2 March 2020
Free-Space Optics and Deep Space Optical Communication request new compact low-power high-stroke high-bandwidth Fast Steering Mirrors. To address this need, CEDRAT TECHNOLOGIES has developed a Magnetically-actuated Fast Steering Mirror called M-FSM, taking heritage of its MICA™ technology. This mechanism offers Rx Ry strokes larger than +/-2° with a 250Hz bandwidth when tilting a 10mm-diameter mirror. Closed loop control is achieved using integrated eddy current sensors. Requested power is reduced leading to low heating and allowing high duty cycle. Vibration tests allow to define first limits and conditions for the M-FSM to bear external vibrations.
Contactless Position sensors for space mechanisms based on eddy current sensing
19 June 2023
For more than 20 years, CTEC has been involved in various space missions, delivering products designed for severe environment conditions (vibrations, shocks, vacuum, humidity, wide thermal range including cryogenic). Eddy current sensor (ECS) technology, using printed circuit board (PCB) for printed coils, provides both a good resolution/accuracy and a good robustness against temperature variations.These sensors are available commercially off the shelf (COTS).