Dust Study, Transport, and Electrostatic Removal for Exploration Missions

Informations projet

DUSTER

N° de convention de subvention: 101082466

DOI

10.3030/101082466

Projet clôturé

Date de signature de la CE 7 Octobre 2022

Date de début 1 Janvier 2023

Date de fin 30 Juin 2025

Financé au titre de

• Digital, Industry and Space

Coût total

€ 1 489 701,25

Contribution de l’UE

€ 1 489 701,25

Coordonné par

INSTITUT ROYAL D'AERONOMIE SPATIALE DE BELGIQUE
Belgium

Periodic Reporting for period 1 - DUSTER (Dust Study, Transport, and Electrostatic Removal for Exploration Missions)

Période du rapport: 2023-01-01 au 2025-06-30

Résumé du contexte et des objectifs généraux du projet

International scientific and commercial interests in exploration missions to solar system bodies such as the Moon, asteroids and comets have increased significantly during the last two decades (e.g. SMART-1, SELENE, LADEE, Chang'e series, Chandrayaan’ series, and Rosetta). Several exploration missions, with and without European contributions, such as the Artemis programme (NASA), are ongoing or planned in the near future. One major environmental constraint during exploration missions is the presence of charged dust-like particles, which are present on the Moon, Mars, comets and asteroids. From an analysis of the effects of lunar dust on Extra-Vehicular Activity systems during the six Apollo missions that landed on the lunar surface, it was found that these effects can take many forms such as dust coating and contamination, thermal control problems and seal failures. One of the most serious effects is the compromising of astronaut health by irritation and inhalation of lunar dust. An example of dust contamination on astronaut’s spacesuit is shown in the attached figure.
Therefore, it is of utmost importance to characterise the properties of the dust particles present on the exploration sites and their transportation mechanisms to enable efficient mitigation techniques to be put in place.
The overall objective of the DUSTER project is to develop the instrumentation and technologies to study dust particles and electrostatic transportation for planetary and small body exploration missions. Specifically, the aim is to design, manufacture and test in a controlled environment a compact multi-sensor instrument for in situ analysis of dust particles. The goal is to propose, after the completion of the project, to include this instrument for a future lunar mission.
Since the behaviour of the dust particles is driven not only by their physical characteristics but also by the surrounding environment, the developed instrument includes sensors to monitor the lunar environment: plasma properties and local electric field. Therefore, the instrument comprises:
- A dust sensor: to attract dust particles and measure their electrical charge and velocity.
- A Langmuir probe to monitor the ambient plasma environment,
- An electric Field (E-field) probe to measure the E-field above the dust surface.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

In order to define the instrument requirements, the charging of dust particles has been studied by both simulations and experimental measurements. The simulations were in close agreement with the experimental data. It has been defined experimentally that the E-field threshold above which it is possible to mobilise charged particles is about 500 kV/m.

Then, the different sub-units that constitute the instrument were designed, built, and tested. After successful testing, the individual sub-units were integrated together to form the instrument. The different parts that were developed during the project are:
- A Data Processing Unit (DPU), to control the different parts of the instrument.
- A low voltage power supply (LVPS) to power the different sub-units.
- A High Voltage Power Supply (HVPS) to bias the dust sensor at a high potential.
- A dedicated software developed to control the different parts of the instrument.
- Three sensors: a Langmuir probe, an electric field (E-field) sensor and the DUST sensor.
- Three front-end electronics, used to read the signals from the sensors (one front-end per sensor).
- Mechanical enclosures for each part of the instrument (electromagnetic and mechanical protections).

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

The DUSTER instrument is unique in several ways:
1) It is the first instrument that uses this measurement principle applied to a lunar representative case with Vacuum Ultra Violet (VUV) and electron irradiation: attracting charged dust particles with high voltages while 1) detecting their displacement, 2) measuring their velocity and 3) retrieving their charge and mass by sensing the faint current generated by the dust particles.
In the past, other teams have already performed displacement of charged dust particles by applying high voltages, but the detections of the dust particles were done optically, with high-resolution cameras. This is a major limitation since 1) optical detection cannot provide the charge of the dust particles and 2) such cameras are bulky and have limited temperature range.
2) Thanks to the extremely high sensitivity of the front-end, the Langmuir probe is able to measure plasma parameters down to 10-4/cm3. To the best of our knowledge, there is no space Langmuir probe that can measure this low density.
3) The E-Field sensor is extremely compact: while E-Field is usually measured on spacecraft using electric sensors a few meters away (up to tens of meters for some missions), the E-Field sensor developed for DUSTER is only 10 mm high, allowing it to be placed as a standalone sensor at the lunar surface, without the need of a boom. To the best of our knowledge, there is no space E-Field sensor as compact as the one developed for DUSTER.
4) This is the first time a space instrument combines a Langmuir probe, a dedicated E-Field sensor and a dust probe. The integration of those three sub-systems allows saving mass, volume, power and simplify greatly the interface to the lander, which are strong assets when considering the participation to a lunar surface mission. With these three instruments combined together, the environment and its impact on the lunar soil is better understood.

In addition, the simulations and experiments performed in the frame of DUSTER provided new key results for the understanding of the lunar dust charging and lofting:
- The measurements in vacuum chamber provide new information on the physical parameters of interest: the charge of individual dust grains together with the charge distribution as a function of time and as a function of the applied electric field. To the best of our knowledge, no equivalent measurements have ever been performed.

Picture of the vacuum chamber where the DUST sensor was tested

Overall diagram of the DUSTER instrument

Picture of Apollo 17 astronaut, Harrison Schmitt. His spacesuit is coated with dust. (NASA)