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Featured Application: Aerospace Science and Engineering—Space Science and Engineering. This research work describes the structural optimization of the MicroMED Dust Analyzer, an Optical Particle Counter developed for the ESA ExoMars 2022 mission. Topology Optimization, a non-conventional design technique was adopted to obtain a lighter component, a valuable achievement for aerospace and space scientific instruments design. In particular, two solutions for the instrument optical bench were proposed and assessed relying on a classical finite element approach, comparing the improved performance with the current design. The optimization outcome proved the adopted design workflow robustness and provided promising results in view of a possible mechanical design enhancement of the MicroMED Dust Analyzer instrument. Indeed, a mass budget saving of about 55% of the considered design domain was achieved, and the dynamic behaviour of the optical bench was improved by up to 50% of the first natural frequency value. Finally, a mockup of the lightened optical bench was manufactured, and the redesign effectiveness was proven by comparing the numerical mechanical resonances with the ones obtained experimentally. An error smaller than 5% was found on the first natural frequency, validating the performed optimization approach. [ABSTRACT FROM AUTHOR]

Airborne dust monitoring is crucial to characterize Martian atmosphere’ thermal structure, balance and dynamics. In order to achieve this objective, the MicroMED instrument has been selected to join the Dust Suite payload within the ExoMars 2020 mission. The particle analyzer is mainly developed to characterize the dust on Mars but, the instrument is suitable to be mounted on different landers or rovers thanks to the limited mass and size. In this study, the design of the instrument has been reported as long as preliminary testing in representative environment of a mockup of the pumping system. [ABSTRACT FROM AUTHOR]

Abstract: This work describes the design and testing of a shutter mechanism for a miniaturized infrared spectrometer developed for the ESA ExoMars Pasteur mission. Unlike most usual cover mechanisms, the conceived one provides a roto-translational motion. This feature allows the sealing of the interferometer main entrance window from dust contamination, in addition to the usual function of shuttering the instrument field of view. Although this characteristic is strongly desired because it avoids dust deposition and optics contamination while the instrument is not operating, it makes the mechanism design significantly more complex. Moreover, challenging design constraints were faced: the mass budget allowed for no more than 30g allocation, the expected working thermal range extended down to −80°C and high vibration levels with an acceleration peak of 670m/s2 were predicted during Mars landing. To complete the picture, the mechanism cover was required to provide also a calibration target for the 2–25μm spectral range of the spectrometer. The resulting system is made by a calibrating/shutter cover moved by a purposely designed out of plane cams system which provides the desired motion. A mechanism mockup was assembled and successfully tested in the predicted thermal and mechanical environments. [Copyright &y& Elsevier]

MicroMED (Micro Martian Environmental Dust Systematic Analyzer (MEDUSA)) instrument was selected for the ExoMars 2020 mission to study the airborne dust on the red planet through in situ measurements of the size distribution and concentration. This characterization has never been done before and would have a strong impact on the understanding of Martian climate and Aeolian processes on Mars. The MicroMED is an optical particle counter that exploits the measured intensity of light scattered by dust particles when crossing a collimated laser beam. The measurement technique is well established for laboratory and ground applications but in order to be mounted on the Dust Suite payload within the framework of ExoMars 2020 mission, the instrument must be compatible with harsh mechanical and thermal environments and the tight mass budget of the mission payload. This work summarizes the thermo-mechanical design of the instrument, the manufacturing of the flight model and its successful qualification in expected thermal and mechanical environments. [ABSTRACT FROM AUTHOR]

MicroMED is an optical particle counter that will be part of the ExoMars 2020 mission. Its goal is to provide the first ever in situ measurements of both size distribution and concentration of airborne Martian dust. The instrument samples Martian air, and it is based on an optical system that illuminates the sucked fluid by means of a collimated laser beam and detects embedded dust particles through their scattered light. By analyzing the scattered light profile, it is possible to obtain information about the dust grain size and speed. To do that, MicroMED's fluid dynamic design should allow dust grains to cross the laser-illuminated sensing volume. The instrument's Elegant Breadboard was previously developed and tested, and Computational Fluid Dynamic (CFD) analysis enabled determining its criticalities. The present work describes how the design criticalities were solved by means of a CFD simulation campaign. At the same time, it was possible to experimentally validate the results of the analysis. The updated design was then implemented to MicroMED's Flight Model. [ABSTRACT FROM AUTHOR]

Space is one of the most avant-garde sectors for additive manufacturing as the inherent characteristics of this technology allow the creation of complex and lightweight 3D structures. Using this brand-new design tool, it was possible to design the pumping system holder of the MicroMED instrument, a particle analyser developed for ExoMars 2022 mission. The geometry of the holder was optimized using a finite element approach. The effectiveness of the proposed solution was evaluated by comparing the performance of two different designs using the AlSi9Cu3 alloy. One solution was based on micro-milling and the other on Selective Laser Melting. In order to validate the designed SLMed holder, a mockup was produced and successfully tested in the mission's mechanical environment. • Structural support based on honeycomb structure has been designed for AM and a mock-up has been realized in AlSi9Cu3. • AM designed structural support provides mass saving and improved dynamic performance compared to micro-milled design. • The breadboard has been tested in a representative mechanical environment for ExoMars 2020 mission. [ABSTRACT FROM AUTHOR]

• MicroMED is the first OPC developed to monitor airborne dust on Mars. • MicroMED is characterized by low mass, size, and power consumption. • The optical design is simplified by using an optical fibre coupled to a laser source. • The optical system is designed to detect dust particles with diameters ≥ 0.4 µm. Airborne dust monitoring is crucial to characterize the thermal structure and evolution of the Martian atmosphere and climate. For this purpose, the MicroMED instrument has been selected within the ExoMars program to be deployed on Mars. It is an optical particle counter that measures the dust amount and size distribution of airborne dust close to the Martian surface. MicroMED is characterized by low mass, size and power consumption and is suitable to be accommodated on both rovers and landers. In this paper, the MicroMED optical design is described along with the analysis performed to prove compliance with all requirements needed for its nominal performance. [ABSTRACT FROM AUTHOR]

• Developed of an optical particle counter able to work in atmospheric Martian condition. • Developed a particular solutions in order to verify the properties of aspiration flow. • Measurement of the maximum displacement of flow outgoing from inlet as function of aspired particles. • Verify of the fluid dynamic properties after to change external Inlet of sensor. Suspended dust has a prominent role in Martian climatology. Several significant dust related phenomena can be observed at various scales, starting from global dust storms to local dust devils, which have important effects such as the increase of troposphere temperature, the modification of the wind regime and the localized motion of sand at the surface. These phenomena depend on dust grain characteristics such as the size distribution or the chemical and bulk composition. Currently, we do not have direct measurement of the dust properties; the only available information in this regard are derived from spectrometric measurements, optical depth, and albedo coming from instruments aboard satellites and in-situ. Herein, we describe the tests performed on the optical particle counter named MicroMED, designed and built to perform the first ever direct in-situ measurement of suspended dust grains in the Martian atmosphere close to the surface. MicroMED is a dust particle size analyzer which was selected to join the Dust Complex payload aboard the ESA/Roscosmos ExoMars 2022 mission. It has the capability to suck in dust that is suspended in atmosphere and to measure the sizes of single grain. The sensor sucks in the dust grains using a sampling system, guides the grains through ducts and concentrates them in an area illuminated by laser. Detecting the intensity of the light scattered by the grains during the crossing through the illuminated area, it is possible to determinate the size of grain. Here we present the innovative techniques in order to verify the performances in terms of dust suction efficiency of the MicroMED Flight Model, using a prototype called MM1. [ABSTRACT FROM AUTHOR]

• The instrument is able to detect particles with high efficiency for most cases. • Effect of environmental parameters on MicroMED's efficiency were analyzed. • The optimum operating conditions of the pump were found. • CFD analysis showed criticalities in MicroMED's Breadboard allowing a design update. Characterization of dust is a key aspect in recent space missions to Mars. Dust has a huge influence on the planet's global climate and it is always present in its atmosphere. MicroMED is an optical particle counter that will be part of the "Dust Complex" suite led by IKI in the ExoMars 2020 mission and it will determine size distribution and concentration of mineral grains suspended in martian atmosphere. A Computational Fluid Dynamic (CFD) analysis was performed aimed at the optimization of the instrument's sampling efficiency in the 0.4–20 µm diameter range of the dust particles. The analysis allowed to understand which conditions are optimum for operations on Mars and to consequently optimize the instrument's fluid dynamic design. [ABSTRACT FROM AUTHOR]