European Space Agency

Enhanced Dual FSA Assembly


The main objective of the program is design, manufacturing and testing an Enhanced Dual FSA (EDF) assembly competitive in performances but also in cost and planning, destined to telecommunication commercial purposes.
The concept of the new structure should accommodate heavier feed chain assemblies up to 30 Kg and a wide range of sub reflectors in position and aperture diameter without modifications of the structure (same manufacturing documentation).
The standardization, industrialization and capability to accommodate heavier feeder and larger sub-reflectors  should be reached at the same time as others important technical objectives:
  • Low mass at relatively high frequency: Mass ≤16 kg ;Freq. ³ 60 Hz
  • To improve the thermo-elastic and stability behaviour of the subs
  • To simplify the assembly process of the  Feed Chain Assembly
  • New interfaces with the satellite and qualified up to -180ºC.
  • New subs materials qualified in the temperature range [-180ºC, +180ºC]
  • To make strong the joints of the FSA upper part between the ribs and the from panel
  • To make strong the joints of the FSA the bottom parts joint between the rear and the front bracket.


This development program has some interesting and challenging aspects:
  • Very innovative shaped rear panel formed by planar and curve parts
  • Interface brackets qualified up to -180ºC
  • Isostatic devices and bracket manufactured by RTM
  • Titanium bracket obtained by ALM process
  • Standard FSA for a wide range the feeders and subs
  • Feed chain assemblies mounted at nominal position
  • Subs supported by isostatic


The most remarkable benefits of the current design are highlighted below:
  • Standard FSA including manufacturing documentation
  • FSA able to support feed chain assemblies up to 30 Kg.
  • Very good thermoelastic behaviour and stability.
  • ITAR free design.
  • Easy assembly process with the corresponding cost and time savings.
  • Good mechanical performances with low mass.
  • Very strong design


The EDF provides a common support for a wide number of subs-reflectors and feeders. The main supporting structure is made by the following sub-assemblies:
  • Rear shaped panel: elements with new design
  • Front panel
  • Internal shear panel
  • Four ribs
  • Two tip ribs: new elements in the design
  • Top and bottom panels: new elements in the design
  • Isostatic devices: new elements in the design
  • Interface brackets: elements with new design


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This design is an important step forward for having a product commercially competitive and with high performances from mechanical and thermo-elastic point of view.


The full development was split in two phases:
  • Phase I: Dedicated to fix the requirement and to obtain a preliminary analysis and design. The phase I activities were developed in the frame of the ARTES 5.2 programme.
  • Phase II: Dedicated to drive the preliminary design to a detailed design and to manufacture and qualify a QM. This phase was developed in the in the frame of ARTES 3.4 programme.

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Current status

The two phases of this development have been finished. The QM was submitted successfully to a complete qualification test campaign.

The new design is being applied to a commercial program and will be the FSA standard product of Airbus Defence and Space (CASA) 

Status date

Monday, August 25, 2014 - 14:10