Space travel is one of humanity's most fantastic aspirations. However, space is the most dangerous environment due to extreme conditions. Reduced-gravity generates disuse muscle atrophy and impaired blood circulation in lower limbs. Therefore, this paper proposes a new biomedical soft robotic system to improve muscle development and promote blood circulation by applying energetically efficient mechanical stimulation to the soft tissues of the astronaut's lower limb and, additionally, to monitor their performance by cotton-based carbon nanotubes biosensors. The computational mechanical simulations performed show a maximum increase in energy optimisation of 89% and a maximum safety factor of 2.75. These preliminary results suggest an increase in the efficiency and safety of the soft robotic device.