27, August 2021

ESA Open Invitation to Tender: 1-10539
Open Date: 27/08/2021 12:02 CEST
Closing Date: 22/10/2021 13:00 CEST

In many science missions, there are sensitive instruments doing precise and crucial measurement onboard. They are susceptible to emission from transmitter and disturbance from other units. Most spacecraft flown today are covered with MLI (Multilayer Insulation) blanket, which is one of the key items used for the spacecraft thermal insulation. One of its additive functions is EM shielding, due to its conductive layers, which is very helpful to protect sensitive units from EM (Electro-Magnetic) disturbance. The EM shielding effectiveness of the MLI was found in the range of 20-40 dB.Recently, some modern MLIs was tested, and the shielding effectiveness was found to be 8 dB lower than its predecessor, which add stress to maintain sufficient margin to ensure EMC.Modern MLI focusses increasingly on thermal properties, while shielding effectiveness degrades. With multi-domain (thermal and electrical) optimization, MLIs could target thermal performance and EM shielding effectiveness in parallel.This study fits very well with the technology strategy of improving the cost efficiency. MLI were originally used only for limiting the heat flow to and from a spacecraft. Today they may also be used to protect against micrometeoroids, atomic oxygen, electron charge accumulation, and rocket plume impingement. However, the inherent functionality of EM shielding is overlooked or neglected, which will be enhanced in this study. With the optimized design, without increasing the amount of component, sufficient EMC margin can be achieved.The study will include the following activities:- identify the design parameters (number, material and thickness of interior layers, thickness of vapour deposited aluminium VDA coating, perforation density, hole size, hole alignment, embossed configuration, spacer material and thickness, outer and inner cover material and thickness, etc.) of MLI which are relevant to shielding effectiveness. The number of MLI types (mainly in terms of materials selected) to be studied will be determined during SoW.- develop a model to predict the shielding effectiveness and thermal performance of MLI based on the identified relevant design parameters. A 2D model (i.e. flat MLI) or a 3D model (e.g. MLI cube) will be specified during SoW.- validate the model by experiment. In case a 3D model is considered necessary, or both a 2D and 3Dmodel will be specified during SoW.- develop a software with user-friendly interface which helps the user to evaluate the shielding effectiveness and thermal performance based on the developed model.- design a MLI with multi-domain (thermal and electrical) optimization, targeting similar thermal performance, with minimised mass impact and improved EM shielding effectiveness (> 20 dB@2GHz)-disseminate the result, include shielding effectiveness test in the product qualification and include shielding effectiveness in product specification.

Directorate: Directorate of Tech, Eng. Quality
Estabilishment: ESTEC
ECOS Required: No
Classified: No
Price Range: 200-500 KEURO
Authorised Contact Person: Maxime Nicolas Gislain Guy
Initiating Service: TEC-EPE
IP Measure: N/A
Prog. Reference: E/0901-01 – Technology Developme
Tender Type: Open Competition
Technology Keywords: 7-C-II-EMC Test Techniques
Products Keywords: 2-O-2-d-Other

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