2, November 2021

ESA Open Invitation to Tender: 1-10691
Open Date: 01/11/2021 10:27 CEST
Closing Date: 21/01/2022 13:00 CEST

The objective of this activity is to develop, manufacture and test innovative concepts of flexible solar array, including interface technologies combining the flexible photovoltaic assembly with the mechanical flexible support. Targeted Improvements:- Increase the solar array power/mass ratio by at least 25% compared to flexible solar arrays currently under development;- Enabling European flexible solar array guaranteeing European independence.Description: Currently, developments are underway in which solar panels are either semi-flexible of fully flexible. Semi-flexible panels are normally sandwiched between conventional panels during launch, in order to achieve adequate stiffness when stowed. When deployed, these same panels extend from a backbone of rigid panels, which provide the necessary stiffness. Fully flexible panels may be rolled up like a carpet during launch. In this way, they form a stiff roll, capable of surviving launch. When deployed, they are either supported by stiff deployable beams on either side, or else kept in tension by means of an extendable boom. In these ways, adequate stiffness in the deployed configuration is achieved. However, a more mass-effective solution could be, for example, based on a curved membrane, rather like that of an inflated balloon (a membrane under bi-axial tension), or else by a curved shell, rather like that of an egg, comprising interlocking thin rigid panels forming shallow shell geometries. Such solutions would open the door to mass savings and hence an improved power/mass performance. Although this potential solution is promising, the technical challenges to overcome are significant. By devising candidate concepts, the mass, stowed volume and stowed/deployed frequencies can be calculated, enabling a trade-off to be performed. The design of the selected concept can then be further detailed, making full use of existing components and subassemblies, where possible. New elements can then be identified and it is these developments that will be the main subject of this activity. Furthermore, new technologies are required to lay down the flexible photovoltaic assembly (PVA) onto the flexible lightweight panel structures. Additional elements that can support the gain in performance (i.e. weight reduction) shall be investigated, such as embedding the harness in panel structures, long size flexible PCBs and flat blocking diodes. After designing and analysing the critical building blocks, breadboards will be manufactured and tested on a breadboard demonstrator, first at panel level and later in combination with flexible PVA.

Directorate: Directorate Telecom Integrated Applica
Estabilishment: ESTEC
ECOS Required: No
Classified: No
Price Range: > 500 KEURO
Authorised Contact Person: Nathalie Dorval
Initiating Service: TIA-TT
IP Measure: N/A
Prog. Reference: E/0534-01G – CC-AT 4.0.1
Tender Type: Open Competition
Technology Keywords: 3-B-I-Photovoltaic Generator Technology
Products Keywords: 2-J-1-a-Photovoltaic Assemblies / 2-J-1.1-b-Structural/mechanical (rigid honeycomb panels, flexible blankets,…) / 2-J-1.1.1-a-Substrates, cover-glass, coatings, adhesives,…

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