Objectives

Define the requirements and interfaces for the instrument to be developed. First, the physical quantities that will
be measured by the instrument will be estimated by analytical models and/or simulation software. Using this
theoretical data set and the experimental data from Task 4.2 (experimental validation of the parameters), the
technical requirements and interfaces for the instrument will be defined.
Specific goals are:
- Theoretical determination of 1) the E-field that is needed to move the charged grains horizontally and
vertically 2) the current resulting from the impact of the charged grains onto the dust electrodes, 3) the
charging parameters (electron density and temperature, VUV flux) and 4) the electric field at the surface of the
dust layer.
- Definition of the technical requirements for the instrument.
- Definition of the internal interfaces and EMC constraints of the instrument.
- Definition of the algorithms that will be implemented in the SW.

Lead / Participants

BIRA-IASB, ONERA, CSIC, TASE

Description

Task 1.1 Theoretical estimation of physical quantity ranges (lead: ONERA)

ONERA: Using analytical models and/or simulation software for dust grains of different materials and with different dimensions, for different charging conditions (e.g. lunar day and night) and for different local surface gravity (e.g. the Moon, asteroids, comets, Mars etc.), estimate 1) the E-field that is needed to move the charged grains horizontally and vertically, 2) the current resulting from the impact of the charged grains onto the HV electrodes, 3) the charging parameters (electron density and temperature, VUV flux) and 4) the electric field at the surface of the dust layer.
For airless bodies, a three stage procedure will be applied: at first a simulation of the plasma environment near the body surface will be performed with SPIS to determine the macroscopic surface conditions (potential, electric field, charged particle fluxes, …). Then a simulation of the individual dust charging in the soil regolith will be performed in order to evaluate the charge and force applied to grains at microscopic scale. From these results, we will finally simulate the dust emission and collection by the instrument at a mesoscopic scale using inputs from both macroscopic and microscopic simulations. For Mars, only the two latest stages will be performed.

Task 1.2 Definition of instrument requirements (lead: BIRA-IASB, participants: CSIC)

BIRA-IASB: Based on the existing literature, models and the output from Tasks 1.1 and 4.2, define the requirements for the instrument to be developed: preliminary functionalities (HW, FW and SW), sensitivity of the front-end electronics (dust electrodes, Langmuir probes and E-field probes), HV level and modulation, budget of the instrument (mass, volume and power), and EGSE commands. Consolidated requirements will be established after Task 4.2.
CSIC: participation in the SW, HW (for DPU) and FW requirement definition, as well as the requirements for the EGSE and analysis of budgets

Task 1.3 Definition of interfaces and EMC constraints (lead: TASE, participants: CSIC,BIRA-IASB)

TASE: Definition of electrical interfaces between the DPU and the analogue front end, the HVPS, the LVPS and the S/C bus.
CSIC: Preliminary definition of SW and FW interfaces and tasks.
BIRA-IASB: Definition of EMC constraints.

Task 1.4 Definition of the algorithms to process the raw data (lead: BIRA-IASB, participant: ONERA, CSIC)

BIRA-IASB: Definition of the algorithms that will be implemented in the SW during task 4.2. The algorithms will be developed to retrieve the required parameters from the instrument’s raw data.
ONERA: Support in the definition of the algorithms, regarding scientific aspects.
CSIC: Support in the definition of the algorithms, regarding future SW implementation aspects.