DUSTER project brings us a step further in tackling the challenge of Lunar dust

The DUSTER project officially and successfully ended in June, but maybe not for long. This two-year project, led by a consortium of Belgian, French and Spanish labs and institutes managed to develop a breadboard instrument to study the behaviour and electrostatic charging of Lunar dust for future Lunar missions. The DUSTER technology can provide complementary data to other types of instruments already developed to measure different properties of moondust. This makes it a promising candidate for future missions like ESA’s AstroLEAP project. AstroLEAP will be a suite of instruments providing in-situ measurements to quantify and understand the complex interactions and dynamics of the lunar surface with e.g., solar radiation, dust, plasma, energetic particles, meteoritic flux, and exosphere.

What is the problem?

The danger of Lunar dust is threefold:

1. The particles are tiny and barely held by the Moon’s weak gravitational field
2. The dust is electrostatically charged by solar UV and X-ray, making it stick to most surfaces
3. Lunar dust is not eroded due to the lack of atmosphere and thus extremely sharp and abrasive

Put this trinity together and you get very volatile and sticky dust, penetrating into the tiniest cracks of instruments, equipment and humans, causing damage to all due to its extreme sharpness and putting both unmanned and manned missions in danger. You can read more about this issue in the article: "DUSTER: Dusting the moon to discover its secrets", or with the fun animation available below:

This is not only a problem on the Moon. Dust of this nature will be present on every solid body - in or outside the Solar System – that is exposed to significant UV flux, cosmic radiation and meteoritic impacts due to the lack of a protective atmosphere. Technology like that developed during the DUSTER project can thus help any mission meant to study an airless body. Think of asteroids, comets, most moons and even some planets.

DUSTER’s proposed solution

Due to its electrostatic charge, Lunar dust is extremely difficult to get rid of. It cannot be brushed off or vacuumed. The only possibilities are to use some type of non-stick coatings on equipment or… to use the exact opposite charge of the dust to attract it away from fragile systems. Trouble is, the electric potential needed to move a dust particle can vary greatly depending on the region, the local topology, the position of the Moon around the Earth’s orbit or the time of the Lunar day (dust particles are mostly positively charged on the day side and negatively charged on the night side).

Therefore, the different teams of the DUSTER project have worked together to design, build and test an instrument capable of measuring the range of properties necessary to understand the dust’s charging and behaviour. This is done using 3 probes:

1. A Langmuir probe, measuring several characteristics of the plasma that is present at the moon’s surface, like the temperature and density of electrons and the ion density.
2. An electric field probe to measure the DC electric field just above the lunar surface
3. A dust collector probe, which is polarised at a high-voltage (between -5000 Volts and +5000 Volts) to attract the dust and measure the current resulting from the movement of the charged dust particles in the Faraday cup.

Put together, the data from the three probes allows us to determine the electric field needed to attract/collect dust, as a function of the local environmental conditions (illumination, plasma density and temperature, etc.). With this information, future missions would be able to design electrostatic dust mitigation devices and dust sample collectors, for a wide range of environments (Moon, Mars, comet, or asteroid).

Who did what?

IASB (Belgium): design of the electronics for the three probes and the high-voltage power supply, and manufacture of two probes (Langmuir and electric field).
ONERA (France): development of the dust probe and management of tests in a vacuum chamber simulating the lunar environment.
IAA-CSIC (Spain): development of the central processing unit, low-voltage power supply, cables, and mechanical and thermal design of the electronics enclosure.

And… it works!

We are glad to report that all of the DUSTER project’s objectives were fulfilled beautifully! We have now a breadboard instrument, capable of measuring the electrical properties and behaviours of Lunar dust, and thus informs the possible methods that could be used to protect equipment and humans on future missions. The DUSTER instrument, designed to study the dust composing the lunar surface (the regolith), is complementary to other existing instruments targeting cosmic dust and already lofted dust.

And the DUSTER adventure may not end there: the instrument is now being proposed as a candidate for the European Space Agency's AstroLEAP project, a payload consisting of several instruments capable of exploring the many facets of the near-surface lunar environment.

Funded by the European Union’s HORIZON Research and Innovation programme under grant agreement No 101082466. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the granting authority. Neither the European Union nor the granting authority can be held responsible for them.