OPTICAL DESIGN AND BREADBOARD OF THE RAMAN SPECTROMETER FOR MMX

This paper reports the laboratory confirmation of an optical design for a 0.2 numerical aperture confocal miniaturized, ruggedized Raman visible light spectroscope (RAX) to be borne by an autonomous rover landed on the martian moon, Phobos

Laser-based soldering technique for hermetical sealing of the calibration target for the exomars' Raman instrument

We propose the laser-based Solderjet Bumping as a full inorganic joining technique for the hermetical sealing of a possible calibration target container for the ExoMars Raman Laser Spectrometer. This technique allows the adhesive free bonding in a flux free and localized soldering process. We show a finite elements analysis based optimization of a soldering adapted design for the calibration target container. Current experimental results document hermetical sealing of a stainless steel tube with BK7 and D263 windows with a helium leakage rate down to 5·10-6 mbar·l·s-1

RAX: The Raman Spectrometer for the MMX Phobos Rover

We present the Raman Spectrometer onboard JAXA’s Martian Moons Exploration (MMX) mission. As part of the MMX Rover, the RAX instrument is built to measure and identify the surface mineralogy of Phobos. This is realized by acquiring Raman spectra in-situ, surveying the geology beneath the Rover body. The RAX data supports the MMX top-level science by providing ground truth information of Phobos, complementary to the samples returned to Earth by the MMX spacecraft. RAX is a very lightweight and highly compact Raman spectrometer with a mass of 1.5 kg and a volume of only approximately 1 dm³. The spectrometer is equipped with a miniaturized and highly sensitive optical assembly, that allows for measuring rather weak Raman signals and enables the identification of water-bearing minerals. The Raman excitation (λ = 532 nm) is realized via a separate laser module based on the Raman Laser Spectrometer (RLS) laser developed for the ExoMars2022 mission. In order to focus the laser onto the Phobos ground below the Rover, the spectrometer includes an autofocus mechanism. The RAX instrument covers a spectral range of 535 to 680 nm, corresponding to a Raman shift of approximately 90 to 4000 cm−1. The spectral resolution over the whole spectral range is about 10 cm−1. This paper presents the design and development of the RAX instrument. The optical performance of the spectrometer is demonstrated using Raman spectra recorded on the physical hardware models. The RAX flight model has been delivered to the MMX Phobos Rover in August 2022. The MMX mission is to be launched in 2024. First RAX data obtained from Phobos are expected in 2027. The RAX instrument is a joint contribution by the German Aerospace Center (DLR), Instituto Nacional de Técnica Aerospacial (INTA) and JAXA

Towards Martian Moons Exploration: micro-Raman and VIS-MIR reflection spectroscopy of the Phobos surface simulants

The Japan Aerospace Exploration Agency (JAXA)’ Martian Moons eXploration (MMX) remote sensing, robotic and sample return mission, scheduled to be launched in 2024 and to return in 2029, will have a strong focus on studying Phobos, including close-up surface analysis and collecting samples for Earth return. A rover, provided by CNES and DLR, will be deployed to Phobos. Its payload includes the Raman spectrometer (RAX) for in-situ characterization of the surface composition. Characterization of payload instrumentation by measurements of planetary simulants is a crucial test for performance and prediction of scientific yield. Controversial conclusions on similarity of infrared reflection and imaging of Phobos to those of low-albedo asteroids imply that combined optical spectroscopy studies will prepare a set of possible clues shortly before the MMX mission. Different Phobos simulants were selected and have been used for Raman and broad range (visible-to-mid-infrared) reflection spectroscopy in order to provide critical parameters on detectivity of mineral phases in the sample matrix as well as to compare the close-up spectroscopy with the known remote sensing of Phobos surface by previous Earth-based observatories and planetary missions

The Raman Spectrometer for Mmx Mission (rax) to Study PHOBOS

Phobos and Deimos are the targets of the coming Martian Moons eXploration mission (MMX) led by JAXA, which will fly to the Martian system and return samples from Phobos with the main goal of determining the origin and evolution of these objects [1, 2]. The characterization of the mineral composition of Phobos' surface is a crucial measurement to achieve the mission goal [3]. The RAman spectrometer for MMX, RAX, on-board the mission rover will provide in situ measurements to characterize igneous phases, secondary minerals, volatiles, and organic species of the surface material at grain scale. RAX was developed together by DLR, INTA/UVA, and JAXA/UTo [4]. RAX was already delivered to CNES and integrated in the MMX rover. MMX rover will be delivered to JAXA this summer. The scientific results of instrument may also be used to support the landing site characterization, and sample return selection