ESA GNC Conference Papers Repository

The SmallGEO product line is OHB?s geostationary orbit telecommunication platform for the telecom satellite market. After the successful launch and delivery of the first two SmallGEO satellites, Hispasat?s H36W-1 and EDRS-C (respectively in 2017 and 2019), OHB is developing two more missions based on the same platform: Electra and Heinrich Hertz (also known as H2Sat). For the first two missions the advantages and use cases for a representative satellite engineering model (known internally as FlatSat) became evident during the verification phase of the AOCS design. A representative FlatSat in terms of hardware, software and ground support equipment allows for early testing and verification of functional chains, something that would otherwise be possible only on the flight hardware. This paper, divided in two main parts, presents the FlatSat?s architecture for the SmallGEO product line and its role in the verification of the AOCS design. Starting from an overview of the AOCS development and test activities, the first part makes a strong case for a representative FlatSat, with a focus on the lessons learnt in the first two SmallGEO missions. The second part details the FlatSat?s architecture for Electra and Heinrich Hertz, and the tailoring to the different needs of the missions.