Shape memory alloy wires modulate the end-effector contact load for sample capture applications.

Sample acquisition from small bodies is a key capability needed for proposed comet and asteroid sample return missions. This investigation determines how to utilize shape memory materials (SMMs) in sampling booms that result in improved sampling capability. By training an SMM wire to remember a given straight or curved shape when heated or cooled down to a given temperature, a long wire with low inherent bending stiffness may be ejected or unreeled from a spacecraft and then transformed into a long thin beam via a controlled material phase transition. Once the phase transition has been induced, the wire exhibits a bending stiffness that did not exist before, and the deployed appendage operates now as a stiff robotic arm.