Periodic Reporting for period 1 - MiLi (Miniaturized LIDAR for MARS Atmospheric Research)
Reporting period: 2022-12-01 to 2023-10-31
Studying the climate on Mars has been a topic for scientific interest since long time already. The composition of the Martian atmosphere and its dust content is a key factor for understanding the climate, which is of vital importance to enable future human exploration of the red planet. The use of Atmospheric LIDARs to characterize densities and sizes of aerosol with a height profile, is commonly used on Earth. However, Earth LiDARs are heavy and with high power consumptions, which make them not easily on-boardable for planetary exploration.
MiLi proposes to increase the Technology Readiness Level (TRL) of the building blocks that will enable the construction of a light and low-power miniaturized LIDAR for Mars atmospheric research, aimed at providing the most precise characterization of the suspended dust and clouds of the atmosphere of Mars to-date. The target mass and power in this miniaturization effort should be around 6 kg and 15 Watt respectively. The critical technologies should demonstrate to be capable of operating at atmospheric temperatures below -40 ⁰C, to minimize the requirements for its accommodation in any lander/rover.
Therefore, the objectives of this project are two-fold:
1. To increase the TRL of different technologies that will allow to build smaller and lighter atmospheric LIDAR instruments, while maintaining the requirements needed for studying the height profile of the Martian atmosphere.
2. To build an Earth model of an atmospheric LIDAR, to validate the use and combination of those technologies on a representative instrument, as a prototype, of future Martian LIDARS.
MiLi proposes to increase the Technology Readiness Level (TRL) of the building blocks that will enable the construction of a light and low-power miniaturized LIDAR for Mars atmospheric research, aimed at providing the most precise characterization of the suspended dust and clouds of the atmosphere of Mars to-date. The target mass and power in this miniaturization effort should be around 6 kg and 15 Watt respectively. The critical technologies should demonstrate to be capable of operating at atmospheric temperatures below -40 ⁰C, to minimize the requirements for its accommodation in any lander/rover.
Therefore, the objectives of this project are two-fold:
1. To increase the TRL of different technologies that will allow to build smaller and lighter atmospheric LIDAR instruments, while maintaining the requirements needed for studying the height profile of the Martian atmosphere.
2. To build an Earth model of an atmospheric LIDAR, to validate the use and combination of those technologies on a representative instrument, as a prototype, of future Martian LIDARS.
MiLi project has successfully completed the Requirement Definition Phase, which was led by the scientific requirements study. During the production of this study, a complete research on the possible scientific returns of the use of a LiDAR in Mars were conducted. More precisely, the following topics were addressed:
a) determination of the aerosol optical (extinction and backscatter coefficients, depolarization ratio) and macro-physical (altitude range, geometrical layer thickness) properties, by using generalized lidar-based methods.
b) estimation of the aerosol micro-physical (effective radius, mass loads) properties by applying advanced inversion methods and models.
c) study of the interactions between dust and clouds (e.g. nucleation, dust scavenging) and the seasonal and year-to-year variability.
The scientific requirement document was then used as the main input to specify the MiLi LiDAR technical requirement document, which has setup a solid base for the ongoing Design Definition Phase.
The design phase started with a concurrent engineering study, carried out by the whole team with the knowledgeable support of the DLR (German Aerospace Center) engineers, at the Institute of Space Systems in Bremen. This study, allowed the consortium to achieve, with a multi-disciplinary approach, the following objectives in a very short period of time:
a) Agreement on requirements and identification of potential non-compliances.
b) Down-selection of identified LiDAR system options into an instrument preliminary design.
c) Define and analyse the initial system budgets (e.g. power, thermal and mass).
d) Identify the required technology test to be carried out, as well the validation and prototyping planning.
In parallel with the definition and design of the LiDAR instrument, the consortium has made strong progress on the maturing of the basic technologies, that will be used as building blocks in the final instrument assembly.
• One of the challenges targeted by MiLi is to fabricate lightweight athermal opto-mechanical components based on novel ceramic nanocomposites that can withstand the severe working conditions under which MiLi’s LiDAR must work. During this period the CINN (Spanish Research Centre of Nanomaterial and Nanotechnology) has worked on the conditioning of innovative ceramic powders (aluminosilicates and metallic carbides) selected for ensuring the thermal stability of the LiDAR telescope. The efforts carried out have allowed to define the best conditions for preparing stable suspensions from the raw materials, and evolved the techniques for sintering by Spark Plasma technique. Both innovations will be used to obtain materials with zero CTE (Coefficient of Thermal Expansion), as well as ready-to-press granules.
• Another innovation of the MiLi project, is the use of new evolving optoelectronics technologies for this kind of instrument, that has never been used before. This is the case of the SiPM (Silicon PhotoMultiplier) sensors, that require less conditioning that typica APD (Avalanche Photodetector) and have a wider dynamic range. During this period INTA (Spanish National Institute of Aerospace Technique) has been characterizing the most advanced sensors of this kind and testing them to assure their suitability for LiDAR instruments.
a) determination of the aerosol optical (extinction and backscatter coefficients, depolarization ratio) and macro-physical (altitude range, geometrical layer thickness) properties, by using generalized lidar-based methods.
b) estimation of the aerosol micro-physical (effective radius, mass loads) properties by applying advanced inversion methods and models.
c) study of the interactions between dust and clouds (e.g. nucleation, dust scavenging) and the seasonal and year-to-year variability.
The scientific requirement document was then used as the main input to specify the MiLi LiDAR technical requirement document, which has setup a solid base for the ongoing Design Definition Phase.
The design phase started with a concurrent engineering study, carried out by the whole team with the knowledgeable support of the DLR (German Aerospace Center) engineers, at the Institute of Space Systems in Bremen. This study, allowed the consortium to achieve, with a multi-disciplinary approach, the following objectives in a very short period of time:
a) Agreement on requirements and identification of potential non-compliances.
b) Down-selection of identified LiDAR system options into an instrument preliminary design.
c) Define and analyse the initial system budgets (e.g. power, thermal and mass).
d) Identify the required technology test to be carried out, as well the validation and prototyping planning.
In parallel with the definition and design of the LiDAR instrument, the consortium has made strong progress on the maturing of the basic technologies, that will be used as building blocks in the final instrument assembly.
• One of the challenges targeted by MiLi is to fabricate lightweight athermal opto-mechanical components based on novel ceramic nanocomposites that can withstand the severe working conditions under which MiLi’s LiDAR must work. During this period the CINN (Spanish Research Centre of Nanomaterial and Nanotechnology) has worked on the conditioning of innovative ceramic powders (aluminosilicates and metallic carbides) selected for ensuring the thermal stability of the LiDAR telescope. The efforts carried out have allowed to define the best conditions for preparing stable suspensions from the raw materials, and evolved the techniques for sintering by Spark Plasma technique. Both innovations will be used to obtain materials with zero CTE (Coefficient of Thermal Expansion), as well as ready-to-press granules.
• Another innovation of the MiLi project, is the use of new evolving optoelectronics technologies for this kind of instrument, that has never been used before. This is the case of the SiPM (Silicon PhotoMultiplier) sensors, that require less conditioning that typica APD (Avalanche Photodetector) and have a wider dynamic range. During this period INTA (Spanish National Institute of Aerospace Technique) has been characterizing the most advanced sensors of this kind and testing them to assure their suitability for LiDAR instruments.
The work carried out has allowed to fix and upscale the synthesis and conditioning of two ceramic compositions featuring ultra-low thermal expansion coefficient. The successful sintering by SPS (Spark Plasma Sintering) of large blanks made with MiLi’s selected compositions has been proven. Furthermore, it has been demonstrated that the ceramic blanks made with one of the compositions can be additionally machined by EDM (Electrical Discharge Machining), what will open the door to cost-effective fabrication of complex shaped components.