Space

Living long-term in space presents extreme challenges that the human body. We evolved within Earth's gravity, atmosphere, and radiation protection and are not equipped the harsh space environment without technology. Current astronauts rely on artificial habitats, exercise regimens, and medical interventions for short- to medium-term stays (e.g., up to a year on the ISS). For true long-term habitation across generations without constant tech support, humans would need significant evolutionary adaptations, either through natural selection over millennia or accelerated via genetic engineering (synthetic biology).