Naked Science examines what interstellar travel would actually demand of the human body and of engineering. Scientists and astronomers lay out the search for Earth-like exoplanets, the propulsion systems that might realistically cover the distances involved, and the radiation exposure a crew would face outside the protection of Earth's magnetic field. The film spends real time on the physical toll of long-duration spaceflight, including bone density loss in zero gravity, and walks through proposed fixes ranging from artificial gravity and next-generation space suits to genetic engineering and suspended animation as ways of getting fragile human bodies across years of empty space. Interviews with researchers and animated diagrams break down propulsion concepts and habitat designs currently in development. Rather than promising an easy future among the stars, the episode treats interstellar travel as an engineering and biological problem still mostly unsolved, weighing which of the proposed solutions are close to feasible and which remain speculative.