Precision actuation of mechanical structures on small spacecraft is challenging. Current solutions include single-use actuators, which rely on pyrotechnics and springs, and multiple-use actuators, which typically consume more size, weight, and power than available on CubeSats. The Folded Lightweight Actuated Positioning System (FLAPS) demonstrates the use of a simple rotary shape memory alloy (SMA) actuator in a bending architecture, along with a feedback control loop for repeatable and precise deployment. The FLAPS mechanism consists of a pair of SMA strips mounted to a hinge assembly, with one side attached to the CubeSat bus and the other to the deployable element. A custom actuator shape was manufactured using oven annealing. SMA actuation is achieved using joule heating. Feedback control is provided by a closed-loop PID control scheme, feedback sensor, and controller board. The FLAPS actuator is currently being developed for CubeSat solar panel positioning and drag control. Other potential FLAPS applications include aperture repositioning, deployable radiators, and steerable antennas. The FLAPS team will validate the actuator system in a microgravity environment on a parabolic fight in late 2019
