E2C3-026 – CHARACTERISATION OF POWER AND THERMAL FUNCTIONAL COATINGS AND SURFACES EXPOSED TO LUNAR DUST FOR EL3 – EXPRO+
21, June 2022

ESA Open Invitation to Tender: 1-11372
Open Date: 08/06/2022 10:07 CEST
Closing Date: 03/08/2022 13:00 CEST

The lunar surface imposes a challenging environment to space hardware. Especially the presence of the lunar dust impacts the performance of functional surfaces and coatings. The lunar surface material (a.k.a. regolith dust) is composed of small sharp-edged particles. These particles adhere to surfaces through adhesion or electrostatic forces. This leads to significant change in the thermo-optical properties. Power hardware and thermal control hardware are amongst the hardware most exposed and directly impacted by the presence of lunar dust. It has been shown in the past that the gradual accumulation and associated degradation of power and thermal functional surfaces reduces their performance. Yet, only very limited information is available about the actual degradation factors which would have to be used in the design. Simulation models are being developed that can predict the rate of dust coverage over time, and limited data from the previous lunar landings and testing is available, but little is known or publicly available about the change in performance (e.g. thermo-optical properties for thermal hardware or visible-wavelength transmissivity of solar cell cover glass) after gradual coverage with lunar dust.This activity aims at performing a set of characterisation tests with the purpose of linking the amount of dust coverage over time to degradation in performance. The following tasks are foreseen:- Identify and select the appropriate technical substrates and lunar regolith simulants. The selection of the simulants will be coordinated with the ESA’s Sample Analogue Curation Facility (SACF) and will need to take into account the anticipated degradation mechanisms for the materials (e.g. abrasion, obscuration, sticking factors)- Identify and implement a non-intrusive test method to quantify the coverage with lunar dust simulant. (NB: given the limited budget an existing test facility will need to be identified, but some setup upgrades may be required).- Perform an extensive test campaign measuring thermo-optical properties (alpha epsilon parameters for radiators, and transmissivity in relevant wavelengths for cover glass), for multiple regolith simulants and dust coverage exposed to a relevant environment in terms of quantities/thicknesses.- Develop a metric to link the dust coverage level (as a function of time or caused by specific events e.g. landing or lunar terminator crossing) to dust degradation factors for radiators and solar cells cover glass.

Estabilishment: ESTEC
ECOS Required: No
Classified: No
Price Range: 200-500 KEURO
Authorised Contact Person: Annika Tenho
Initiating Service: HRE-E
IP Measure: N/A
Prog. Reference: E/0187-02L – EL3 E3P Per. 2
Tender Type: Open Competition
Open To Tenderers From: AT+BE+CA+CH+CZ+DE+DK+GR+ES+FR+GB+HU+IE+IT+LU+LV+NL+NO+PL+PT+RO+SE+SI
Technology Keywords: 21-D-I-Coatings and Insulation
Products Keywords: 2-O-all.1.1-a-Coatings (black paints, sulphuric oxidation, aluminium, gold,…)

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