The Martian Moons eXploration (MMX) mission led by JAXA will conduct remote sensing of both Martian moons Phobos and Deimos and in-situ observations and return samples from Phobos. A small rover will be operating on Phobos’ surface and perform scientific measurements, in particular with its Raman Spectrometer for MMX (RAX). The instrument is jointly developed by DLR with partners from Spain (INTA, University of Valladolid) and Japan (JAXA, University of Tokyo). With its more than 20 optical elements (e.g. laser, lenses, mirrors, grating, dichroic beam-splitters, spectral filters), the optical alignment and integration of this very compact Raman spectrometer was one of the biggest challenges of the instrument development at DLR. This article will cover the different steps of alignment with 1) the integration of the lenses in each individual lens group, 2) the alignment and integration of each lens group to build the spectrometer, and 3) the global alignment verification of the end-to-end instrument. The main goal was to integrate the optical elements in RAX’s mechanical housing providing maximized scientific performance. This meant for example that the detector’s sensitive surface had to be precisely placed at the focal plane surface of the imaging objective to optimize the spectral resolution, but also that the confocality of the laser output (and image on Phobos’ surface) with the spectrometer slit had to be very accurately adjusted to optimize the Signal to Noise Ratio of the Raman features. Aligning and integrating a state-of-the art Raman spectrometer in a very compact volume of less than 10x10x10 cm³ and a mass lower than 1.5 kg was challenging but successful. The different tests performed on the instrument presented here also showed the robustness of the design and demonstrated that RAX can perform excellent scientific measurements on Phobos.
Raman Laser Spectrometer (RLS) is one of the Pasteur Payload instrument of the ExoMars 2020 mission, within the ESA’s Aurora Exploration Program. RLS is mainly composed by SPU (Spectrometer Unit), iOH (Internal Optical Head), and ICEU (Instrument Control and Excitation Unit), and will analyse Mars surface and sub-surface crushed samples by Raman spectroscopy. For the RLS Flight Model (FM) verification campaign, an end-to-end quick functional test was developed to evaluate the instrument performances stability. This test consists on a comparison of the centre pixel and the FWHM (Full Width at Half Maximum) of a set of Ne calibration lamp peaks, and was decided to be done before and after ever risky activity (transport, thermal tests, etc.) In the course of the end-to-end functional test carried out on RLS FM as part of the pre-delivery checks, an increment on the FWHM calibration lamp peaks was observed. Such performance variation was also noted to be dependent on the way the SPU thermal strap was assembled and the environmental conditions (P and T) in which the spectra were acquired. For that reason, a new SPU thermal strap assembly procedure was decided to be designed in order to ensure no extra negativeeffect was going to appear during the RLS FM installation on the ALD (Analytical Laboratory Drawer) and the instrument flight operation. In this paper, a deep exploration of the conditions in which such “de-focus” (probably due to an excessive thermal gradient between SPU structure and CCD) appears is carried out, demonstrating that the new thermal strap assembly procedure minimizes an incidental extra de-focus appearance during RLS installation on the ALD.
The Raman Laser Spectrometer (RLS) is one of the Pasteur Payload instruments within the ESA’s ExoMars mission. The RLS instrument scientific goal consists of perform in-situ Raman spectroscopy over different organic and mineral powder samples of the Mars subsoil. It consists of three main units: SPU (Spectrometer Unit), iOH (Internal Optical Head), ICEU (Instrument Control and Excitation Unit) which are interconnected by an optical and electrical harnesses (OH and EH).
The SPU is one of the most critical units of the RLS instrument. The Engineering Qualification Model (EQM) unit has been already delivered after a proper qualified campaign in a very demanding environment with very restrictive design constraints, including Planetary Protection requirements. Also, a complete set of functional tests had been carried out under representative environment, simulating not only Mars rover´s laboratory conditions (thermal range and pressure), but also the cruise phase. Previously, an exhaustive qualification campaign was developed with two different purposes: to mitigate the risks associated to new optical elements included in the design and without space heritage; and to obtain a detailed comprehension of their behaviour under Mars conditions for facing the Flight Model (FM) optical design with guarantee of success.
EQM results were successful in terms of Engineering, and a SWaP-optimized system had been reached. The acquired knowledge of that model has been used to implement little improvements into SPU FM for acceptance. For operations, a big amelioration has been the reduction of the image ROI on the Charge-Coupled Device (CCD) after the improving of the alignment of the inclination degree of the image plane on CCD under the tightly integration constrains, letting to download the minimum necessary data bytes. These improvements achieved by a proper analysis of the image on the SPU CCD will allow to evaluate far better the Raman spectrum effects.
SPU FM Mechanical, Thermal-Vacuum campaign has been already finished in order to accept for flight the current unit which will be already completed and “flight qualified” at RLS system level before the congress. If everything continues on this way, the desired Technology Readiness level, TRL 8 maturity level, will be reported during the following text.
In the framework of the ESA’s Aurora Exploration Programme and, in particular, of the ExoMars mission, the Raman Laser Spectrometer (RLS) will be in charge of performing out planetary Raman spectroscopy for the first time. The instrument is located inside the Rover at the Analytical Drawer (ALD) and will analyze powdered samples obtained from the Martian subsurface in order to determine the geochemistry content and elemental composition of the minerals under study. After the RLS instrument successful qualification, the Flight Model (FM) development and the acceptance verification activities started. Among the different units RLS is composed on, i.e. its three main units that are interconnected by optical fibers and electrical harness, iOH (Internal Optical Head), SPU (Spectrometer Unit) and ICEU (Instrument control and Excitation Unit) which also contains the Raman excitation laser diode, iOH FM information can be found in this paper. RLS iOH unit is in charge of focusing the Raman excitation signal onto the sample, receiving the Raman signal emitted by the sample and focusing this signal in the output optical fiber that is directly connected to SPU unit. As for the rest of RLS instrument FM subunits, and before their final assembly and system level tests, RLS iOH FM exhaustive and complete characterization process was carried out, not only at room conditions but also at relevant environmental conditions: vacuum condition along the operational temperature range with acceptance margins (from -50 to 8ºC). In this paper, and after to carry out the RLS iOH FM proper integration and alignment process, the activities accomplished during the performance verification and the obtained results are reported on
Raman Laser Spectrometer (RLS) is the Pasteur Payload instrument of the ExoMars mission, within the ESA’s Aurora Exploration Programme, that will perform for the first time in an out planetary mission Raman spectroscopy. RLS is composed by SPU (Spectrometer Unit), iOH (Internal Optical Head), and ICEU (Instrument Control and Excitation Unit). iOH focuses the excitation laser on the samples (excitation path), and collects the Raman emission from the sample (collection path, composed on collimation system and filtering system). Its original design presented a high laser trace reaching to the detector, and although a certain level of laser trace was required for calibration purposes, the high level degrades the Signal to Noise Ratio confounding some Raman peaks. So, after the bread board campaign, some light design modifications were implemented in order to fix the desired amount of laser trace, and after the fabrication and the commitment of the commercial elements, the assembly and integration verification process was carried out. A brief description of the iOH design update for the engineering and qualification model (iOH EQM) as well as the assembly process are briefly described in this papers. In addition, the integration verification and the first functional tests, carried out with the RLS calibration target (CT), results are reported on.
A miniaturized diode-pumped solid-state laser (DPSSL) designed as part of the Raman laser spectrometer (RLS) instrument for the European Space Agency (ESA) Exomars mission 2020 is assembled and tested for the mission purpose and requirements. Two different processes were tried for the laser assembling: one based on adhesives, following traditional laser manufacturing processes; another based on a low-stress and organic-free soldering technique called solderjet bumping technology. The manufactured devices were tested for the processes validation by passing mechanical, thermal cycles, radiation, and optical functional tests. The comparison analysis showed a device improvement in terms of reliability of the optical performances from the soldered to the assembled by adhesive-based means.
F. Rull, A. Sansano, E. Díaz, C. P. Canora, A. Moral, C. Tato, M. Colombo, T. Belenguer, M. Fernández, J. A. R. Manfredi, R. Canchal, B. Dávila, A. Jiménez, P. Gallego, S. Ibarmia, J. A. Prieto, A. Santiago, J. Pla, G. Ramos, C. Díaz, C. González
The Raman Laser Spectrometer (RLS) is one of the Pasteur Payload instruments, within the ESA's Aurora Exploration
Programme, ExoMars mission.
ExoMars 2018 main Scientific objective is "Searching for evidence of past and present life on Mars".
Raman Spectroscopy is used to analyze the vibrational modes of a substance either in the solid, liquid or gas state. It
relies on the inelastic scattering (Raman Scattering) of monochromatic light produced by atoms and molecules. The
radiation-matter interaction results in the energy of the exciting photons to be shifted up or down. The shift in energy
appears as a spectral distribution and therefore provides an unique fingerprint by which the substances can be identified
and structurally analyzed.
The RLS is being developed by an European Consortium composed by Spanish, French, German and UK partners. It will
perform Raman spectroscopy on crushed powdered samples inside the Rover's Analytical Laboratory Drawer.
Instrument performances are being evaluated by means of simulation tools and development of an instrument prototype.
F. Rull, A. Sansano, E. Díaz, M. Colombo, T. Belenguer, M. Fernández, V. Guembe, R. Canchal, B. Dávila, A. Sánchez, H. Laguna, G. Ramos, C. González, D. Fraga, P. Gallego, I. Hutchinson, R. Ingley, J. Sánchez, C. Canora, A. Moral, S. Ibarmia, J. A. Prieto, J. A. R. Manfredi, P. Cabo, C. Díaz, A. Jiménez, J. Pla, R. Margoillés
The Raman Laser Spectrometer instrument is included in ExoMars program Pasteur payload and it is focused on the
Mars samples analytical analysis of the geochemistry content and elemental composition of the observed crushed
samples obtained by the Rover.
One of the most critical Units of the RLS is the Spectrometer unit (SPU) that performs Raman spectroscopy technique
and operates in a very demanding environment (operative temperature: from -40 ºC to 6 ºC) with very restrictive design
constraints. It is a very small optical instrument capable to cope with 0.09 nm/pixel of resolution. The selected solution is
based on a single transmisive holographic grating.
At this stage of the project SPU Team is preparing the Conceptual Design Review that will take place at the end of
October 2011.
E. Díaz, A. Moral, C. Canora, G. Ramos, O. Barcos, J. A. Prieto, I. B. Hutchinson, R. Ingley, M. Colombo, R. Canchal, B. Dávila, J. A. R. Manfredi, A. Jiménez, P. Gallego, J. Pla, R. Margoillés, F. Rull, A. Sansano, G. López, A. Catalá, C. Tato
The Raman Laser Spectrometer (RLS) is one of the Pasteur Payload instruments, within the ESA's Aurora Exploration
Programme, ExoMars mission.
The RLS Instrument will perform Raman spectroscopy on crushed powdered samples deposited on a small container
after crushing the cores obtained by the Rover's drill system.
In response to ESA requirements for delta-PDR to be held in mid 2012, an instrument BB programme has been
developed, by RLS Assembly Integration and Verification (AIV) Team to achieve the Technology Readiness level 5
(TRL5), during last 2010 and whole 2011. Currently RLS instrument is being developed pending its CoDR (Conceptual
Design Revision) with ESA, in October 2011.
It is planned to have a fully operative breadboard, conformed from different unit and sub-units breadboards that would
demonstrate the end-to-end performance of the flight representative units by 2011 Q4.
The Raman Laser Spectrometer is scheduled for launch on board the ESA ExoMars mission in 2018. Its purpose is to
perform analysis of the Raman signal scattered from crushed core samples retrieved from up to 2m below the Martian
surface. In support of this activity an RLS breadboard instrument has been assembled whose focal plane incorporates an
inverted mode CCD cooled to between -10°C and -40°C. The thermal, mechanical and detector design of this elegant
breadboard instrument focal plane is described, and the system performance is evaluated in terms of the noise
characteristics and dynamic range.
F. Rull, A. Sansano, E. Díaz, C. Canora, A. Moral, C. Tato, M. Colombo, T. Belenguer, M. Fernández, J. A. Manfredi, R. Canchal, B. Dávila, A. Jiménez, P. Gallego, S. Ibarmia, J. A. Prieto, A. Santiago, J. Pla, G. Ramos, C. González
The Raman Laser Spectrometer (RLS) is one of the Pasteur Payload instruments, within the ESA's Aurora Exploration
Programme, ExoMars mission.
The RLS Instrument will perform Raman spectroscopy on crushed powered samples deposited on a small container after
crushing the cores obtained by the Rover's drill system. This is the first time that a Raman spectrometer will be launched
in an out planetary mission.
The Instrument will be accommodated and operate inside the Rover's ALD (Analytical Laboratory Drawer), complying
with COSPAR (Committee on Space Research) Planetary Protection requirements.
The RLS Instrument is composed by the following units: SPU (Spectrometer Unit); iOH: (Internal Optical Head); ICEU (Instrument Control and Excitation Unit).
Other instrument units are EH (Electrical Harness), OH (Optical Harness) and RLS SW On-Board.
The CTU (Cryogenics Translation Unit) is a low range (±1 mm) high resolution (<50 nm) translation unit to be used at
cryogenic temperature (20K). The unit is a multipurpose device capable of fine closed loop positioning. This device can
be used as active element in IR Instrumentation for compensating thermo-elastic deformation moving optical elements
or sensors.
CTU motion system is based in thin flexures deformation to assure repeatability and moves in closed loop mode by
means of a fine linear actuator and a calibrated non contact capacitive sensor.
This paper describes main design features, how cryogenic testing of main requirements was carried out (including
methodologies used for calibration and submicron verification), tested performances, and main lesson learned during the
development.
The MTS Folding Mirror Subsystem is part of the MIRI Telescope Simulator, which is an Optical Ground Support
Equipment for ESA MIRI (Medium Infrared Instrument) Qualification, in the frame of the James Webb Space
Telescope Program. The program prime contractor is INTA (Spanish National Aerospace Centre).
The Subsystem consists of four different mirrors assemblies to adapt the optical path to the available envelope; the
mirrors are placed between exit pupil and image plane with suitable orientation to reproduce specific chief ray deviation.
Remote adjustment for image compensation at cryogenic conditions is available for two mirror assemblies, by means of
two independent rotation mechanisms. A manual tip-tilt system is also provided for system adjusting at ambient
conditions in all four mirror assemblies.
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