Exo-Muscular Systems Based On SMA For Space Suits

A flexible exo-muscular system based on Shape Memory Alloy actuators has been developed for the assistance of astronauts in microgravity. Three different SMA actuators have been developed to face several problems related to the life in space.

Two actuators are proposed for the exercising of astronauts for the mitigation of some of the problems of microgravity. These actuators are focused on reducing the effects of loss of bone density and muscular mass in the legs. Ankle Lateral Actuating System (ALAS) is suggested for exercising the muscular groups involved in the inversion and eversion of the ankle. Smart Elastic Bands System (SEBS) is proposed as exercising devices that exert resistive loads to the flexion and extension of the knees, thus training both the quadriceps and the hamstrings.

A third actuator, the Hand Exo-Muscular System (HEMS) is designed for the assistance of astronauts during Extra-Vehicular Activities (EVA). The device is intended to reduce the astronauts hand fatigue when performing manual tasks during EVA. This fatigue is produced by the opposition force exerted by the pressurized gloves of the space suit.

Description of the actuators, their different design strategies and the results of the validation test campaign will be presented in this work.