DETERMINATION OF A GENERIC BASELINE FOR CABLE BENDING RADII LIMITS – EXPRO PLUS
15, February 2022

ESA Open Invitation to Tender: 1-11072
Open Date: 11/02/2022 14:52 CEST
Closing Date: 25/03/2022 13:00 CEST

Robustness of the harness design is required to ensure its function and longevity. Most harnesses in space systems are used in static applications. Nevertheless, the increasing interest in rovers and robotic systems will lead to more dynamic applications, with overall higher constraints on cable bending. In addition, the need for complex and highly integrated systems demands very efficient use of available volumes. To face these challenges and comply with the increasing constraints on harness routing and accommodation, harness bending radii need to minimised to achieve a compact, space-saving routing without compromising the integrity of the harness material. Over-bending of a harness can lead to plastic deformation and cracks in the insulation or even breaking shield or conductor strands.The specifications of the ESCC (European Space Components Coordination) 3901 cable family, used in almost all applications, do not provide bending radius limits. In addition, no ECSS (European Cooperation for Space Standardization) standard currently provides a set of generic rules for cable bending radii limits, which can be used as a guideline for harness designers.As a result, different other standards (e.g. by NASA, CNES, IPC) are applied and often conservative approaches are taken to ensure harness integrity. These standards in parts differ heavily, not taking into account the peculiarities of the different cable insulations used in ESCC3901, knowing that the insulation material greatly affects flexibility and robustness of a wire/cable and hence limits its minimum bending radius.The goal and benefit of this activity would be to clarify the discrepancies in existing standards by extensive testing and pushing the limits for (minimum) bending radii of harnesses. This activity encompasses the following tasks:- Establish a technical rationale and lay down success criteria accordingly- Procure cables according to ESCC 3901 as well as comparable commercial cables covering all applications- Test cables and bundles thermally, mechanically and electrically- Establish a robust and reliable set of bending radius limitsProcurement Policy: C(1) = Activity restricted to non-prime contractors (incl. SMEs). For additional information please go to this link.

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: C1
Prog. Reference: E/0901-01 – Technology Developme
Tender Type: Open Competition
Open To Tenderers From: AT+BE+CH+CZ+DE+DK+EE+EL+ES+FI+FR+GB+HU+IE+IT+LU+NL+NO+PL+PT+RO+SE
Technology Keywords: 23-B-I-Passive Components
Products Keywords: 1-C-1-o-Wires and cables / 2-B-1-o-Wires and cables

If you wish to access the documents related to the Invitation to Tender, you have to log in to the ESA Portal.