Solar Array Deployment Mechanism for OneWeb Satellites

The AOS Airbus OneWeb Satellites mega constellation for global broadband internet consists of 900 small satellites. AOS selected SpaceTech to develop and deliver 1800 deployment mechanisms – two on every satellite.

SpaceTech AOS Airbus OneWeb satelliteAirbus OneWeb satellite

Delivering key parts to make this project a success, SpaceTech proves its suitability for the New Space Market as a flexible and cost-efficient SME. SpaceTech was able to provide AOS with a QM development of only three months and delivered the SADM flight hardware for 12 pilot satellites that are already built at Airbus in France.

Key features and deployment process for OneWeb

SpaceTech’s AOS SADMs consist of a CRFP booms and SAP launch support parts.
The booms are equipped with two tape spring hinges and the harness for the solar array and the seasonal drive. The challenging requirement of available space between spacecraft body and solar panel was achieved by squeezing the CFRP boom. The CFRP boom with integrated high strength alloy tape springs is manufactured by Carbospacetech (owned by SpaceTech to 66 %) and provides a high stiffness in deployed configuration. The power harness is directly attached to the boom and provides high performance due to its low resistance.
Safe launch suspension is achieved by one release mechanism that pretensions the solar array panel and the boom. The deployment process can be divided into three steps:
1.    Release of the HDRM. The solar panel is still caught by
the hook-roller–combination.
2.    Driving the seasonal drive, that results in a partly latching of the boom hinges.
3.    Further driving the seasonal drive, which releases from the hook and fully deploys the solar array panel.

Testing of complete deployment sequence for OneWeb

Extensive testing of the complete deployment sequence on a STI developed Zero-G robotic arm in combination with in-orbit analysis showed the robustness and reliability of the SADM. The guided deployment and the robust design ensures a safe deployment without any risk of overswinging, spring delatching.
The use of the seasonal drive of the panel for the deployment process, allows for a highly cost efficient and robust deployment mechanism, essential to meet the challenging AOS cost targets.

To ensure a fast, efficient and cost attractive development process, the verification of the dynamic deployment was performed by a combination of an in-house-developed fixed-body simulation tool and a robotic gravity compensation that ensures highly realistic zero-g situation even during dynamic deployment. This combination and good correlation between test and analysis convinced the customer of the delivered system.
Following figure gives an impression of the simulation visualization and the QM test setup.

SpaceTech AOS satellite deployment mechanism QM test setupSimulation of the release in comparison to QM test setup

OneWeb launch

The launch of six pilot satellites took place February 27th, 2019 and the solar arrays deployed successfully. The mega constellation launch of 900 Airbus OneWeb satellites is planned to be started beginning of 2020.