Micro-Ares, An electric field sensor for ExoMars 2016

International audienceFor the past few years, LATMOS has been involved in the development of Micro-ARES, an electric field sensor part of the science payload (DREAMS) of the ExoMars 2016 Schiaparelli entry, descent and landing demonstrator module (EDM). It is dedicated to the very first measurement and characterization of the Martian atmospheric electricity

Micro-ARES, an electric-field sensor for ExoMars 2016: Electric fields modelling, sensitivity evaluations and end-to-end tests.

International audienceFor the past few years, LATMOS has been involved in the development of micro-ARES, an electric field sensor part of the science payload (DREAMS) of the ExoMars 2016 Schiaparelli entry, descent and landing demonstrator. It is dedicated to the very first measurement and characterization of the Martian atmospheric electricity which is suspected to be at the very basis of various phenomenon such as dust lifting, formation of oxidizing agents or Schumann resonances. Although the data collection will be restricted to a few days of operations, these first results will be of importance to understand the Martian dust cycle, the electrical environment and possibly relevant to atmospheric chemistry. The instrument, a compact version of the ARES instrument for the ExoMars Humboldt payload, is composed of an electronic board, with an amplification line and a real-time data processing DSP, which handles the electric signal measured between the spherical electrode (located at the top of a 27-cm high antenna) that adjusts itself to the local atmospheric potential, and the lander chassis, connected to the mechanical ground. Since the electric fields on Mars have never been measured before, we can rely on two sources in order to know their expected order of magnitude. The first one is the measurement of the atmospheric electric fields on Earth, at the surface (in dust storms or the so-called dust-devils) or in the high atmosphere (closer to the Martian temperature and pressure conditions). The second one is the computer simulation of the phenomenon, that we obtained by combining two models. On the one hand, the mesoscale PRAMS model, developed at SwRI, which has the ability to simulate the dust transportation, and on the other hand the implementation made at LATMOS of Farell's 2005 dust-triboelectricity equations. Those models allowed us to simulate electric fields up to tens or even hundreds of kilo-volts per meter inside dust devils, which corresponds to the observations made on Earth and transposed to the Martian atmospheric parameters. Knowing the expected electric fields and simulating them, the next step in order to evaluate the performance of the instrument is to determine its sensitivity by modelling the response of the instrument. The last step is to confront the model of the instrument, and the expected results for a given signal with the effective outputs of the electric board with the same signal as an input. To achieve this end-to-end test, we use a signal generator followed by an electrical circuit reproducing the electrode behaviour in the Martian environment, in order to inject a realistic electric signal in the processing board and finally compare the produced formatted data with the expected ones

The DREAMS experiment on the ExoMars 2016 mission for the study of Martian environment during the dust storm season

International audienceThe ExoMars programme, which is carried out by European Space Agency (ESA) in cooperation with the Russian federal Space Agency (Roscosmos), foresees a two-steps mission to Mars. The first mission consists of an orbiter and an Entry Descent and Landing Demonstrator Module (EDM) to be launched in January 2016 and is scheduled to land on the planet during the statistical dust storm season; the second mission includes a descent module, a surface platform and a rover and will be launched in 2018. The DREAMS (Dust characterization, Risk assessment and Environment Analyser on the Martian Surface) experiment for ExoMars 2016 is an autonomous meteorological station designed to study the effect of dust on Martian environment which will operate for two Martian days (sols) relying on its own power supply after landing. DREAMS includes a suite of sensors able to analyse temperature, pressure, humidity, wind speed and direction and solar irradiance as well as an electric field probe which will perform the first electrical characterization of Mars surface atmosphere

Pre-flight Calibration and Near-Earth Commissioning Results of the Mercury Plasma Particle Experiment (MPPE) Onboard MMO (Mio)

BepiColombo Mio (previously called MMO: Mercury Magnetospheric Orbiter) was successfully launched by Ariane 5 from Kourou, French Guiana on October 20, 2018. The Mercury Plasma/Particle Experiment (MPPE) is a comprehensive instrument package onboard Mio spacecraft used for plasma, high-energy particle and energetic neutral atom measurements. It consists of seven sensors including two Mercury Electron Analyzers (MEA1 and MEA2), Mercury Ion Analyzer (MIA), Mass Spectrum Analyzer (MSA), High Energy Particle instrument for electron (HEP-ele), High Energy Particle instrument for ion (HEP-ion), and Energetic Neutrals Analyzer (ENA). Significant efforts were made pre-flight to calibrate all of the MPPE sensors at the appropriate facilities on the ground. High voltage commissioning of MPPE analyzers was successfully performed between June and August 2019 and in February 2020 following the completion of the low voltage commissioning in November 2018. Although all of the MPPE analyzers are now ready to begin observation, the full service performance has been delayed until Mio’s arrival at Mercury. Most of the fields of view (FOVs) of the MPPE analyzers are blocked by the thermal shield surrounding the Mio spacecraft during the cruising phase. Together with other instruments on Mio including Magnetic Field Investigation (MGF) and Plasma Wave Investigation (PWI) that measure plasma field parameters, MPPE will contribute to the comprehensive understanding of the plasma environment around Mercury when BepiColombo/Mio begins observation after arriving at the planet Mercury in December 2025