European Space Agency

GaAs Evo1 Solar Arrays Product Family for Spacebus™ 4000C


The development is a renewal of the Spacebus solar array family with a huge redesign to cost and standardisation approach for Telecom Spacebus 4000C overall range.


The key issues during this full renewal of the family has been the huge need of justification file “update” and “cleaning” till the lowest level of component in order to get a full CDR package “reset” and self-content.


Benefits of this development are double: recurring cost and recurring schedule reductions. Those benefits come both from standardization effort at each level and mainly at panel substrate and photo-voltaic network assembly levels. 


Standardized Solar Array Family of 3, 4 and 5 panels family has been built from single substrate design and with two panels PVA layout variants (one full panel and one descoped variant with 4 sections i/o 5)

The descoping panel by panel trick has allowed getting with limited parts references a set of 15 wings ranging till 17KW EOL.

The standardization and design robustness to any configuration allow the recurring cycles reductions (panels anticipation) and the use of 30% BOL large cells allows drastic cost reductions.


Project plan has mainly consisted in the standard PVA conception, analysis and then detailed design with standardized levels to fit all the panels location in any wing.

The mechanical architecture has supported this evolution of network design, providing a new 5 panels wing with 3 transfer panels and reuse of 3 and 4 panels wing architectures.

All the supporting components have been developed in parallel to get this solar array, including mainly secured connections, reinforced panels and high tension hold down points.

Current status

Completion of CDR in December 2013 has shown a ready to use solar array design file and justification file with easily scalable power output. The first application program offers the opportunity to qualify the Solar Array wing through a PFM approach. The PFM wing is of W41S4 type: 4 panels in a row, more than 14 kW Solar Array power (EOL). This wing is installed on a SPACEBUS™4000C4 to be flown in 2017.

Status date

Friday, May 14, 2021 - 14:30