Compact and Cost-Effective Solar Array Drive Mechanisms to Enable High-Performance Small Satellites

To enhance spacecraft power generation, deployable solar arrays are often used to increase the surface area available for solar cells. To maximize their effectiveness, a solar array drive mechanism (SADM) can be implemented, allowing independent array rotation from the spacecraft body. This capability is particularly valuable for Earth observation and target-tracking missions, where it enables continuous power generation despite spacecraft orientation limitations. This paper presents the design, analysis, and qualification testing of two low-cost SADMs: the SolarDrive-μ for microsatellites and the SolarDrive-S for small satellites. Each SADM consists of two primary elements—the drivetrain and the twist capsule—both designed with commercial off-the-shelf components to minimize costs. A solar array power generation analysis for each class of spacecraft determined the required number of power feedthroughs for each SADM, while a drivetrain performance analysis confirmed positive torque margins using the selected motors and gearing. Thermal analysis demonstrated that all electrical components, including the flexible printed circuits, remain within their operational temperature limits. To qualify these SADMs for future Space Flight Laboratory missions, a comprehensive testing campaign—including vibration, thermal vacuum, radiation, and lifetime testing—has been designed to qualify these mechanisms to Technology Readiness Level 6.