Speakers
Description
The increasing reliability demands of New Space missions require rigorous environmental qualification of satellite subsystems. In this context, UMBRAGROUP S.p.A., in collaboration with SERMS Test Center (Terni, Italy), performed a complete environmental and structural test campaign on the Joint Brake mechanism of an IOS (In Orbit Servicing) platform. The qualification activities addressed three critical areas—thermal vacuum, vibration, and pyroshock—using ECSS compliant high performance facilities. This work presents the tailored test setups, mission driven qualification levels, and high fidelity monitoring combined with systematic post test functional assessment.
Thermal vacuum testing was performed in the SERMS TVAC chamber (pressure <10⁻⁴ Pa) across −60℃ to +100℃. The key challenge was the tribological behavior of the friction material in vacuum, where outgassing, adhesion changes, and modified wear mechanisms can affect torque stability.
Vibration qualification reached 35 Grms using electrodynamic shakers and dedicated fixtures, with focus on structural stiffness and modal stability above the required 200 Hz resonance threshold. Pyroshock testing achieved 2000 g, verifying mechanical robustness along all axes.
Particular attention is given to the challenges associated with testing actuated mechanical subassemblies: to meet the stringent time and cost constraints of the New Space Economy, the brake was actuated directly inside the thermal vacuum chamber using a characterized rotary feedthrough. This approach eliminated the need for a large chamber—reducing energy consumption—and allowed the performance test bench to remain outside the vacuum environment. As a result, the bench did not
require vacuum compatible components (e.g., motors, lubrication systems, dedicated cabling), enabling significant savings in both complexity and cost.
This contribution illustrates a robust, ECSS compliant approach to qualifying mechanical subsystems for New Space missions through the combined use of UMBRAGROUP’s test benches and SERMS’s environmental facilities. The lessons learned contribute to the broader SmallSat community through practical insights on subsystem qualification, support ongoing optimization of test tailoring for low mass actuated components and highlight the joint capabilities as strategic assets for Small-Sats.