X52: Prolonged stay in weightless environment

Prolonged stay in a weightless environment refers to a group of medical conditions that occur due to extended exposure to zero or microgravity environments, such as those experienced during space travel. The human body, which has evolved under Earth's gravity, undergoes various physiological changes in response to weightlessness. Some of these changes include muscle atrophy, demineralization of bones leading to osteoporosis-like conditions, fluid redistribution with facial swelling and leg thinning, and cardiovascular deconditioning due to the lessened work of the heart. Additionally, individuals might face challenges with coordination and balance, and altered circadian rhythms leading to sleep disturbances. Some astronauts have also reported vision changes, potentially due to increased intracranial pressure. Most of these conditions are reversible upon return to Earth, however, the complete long-term effects remain a subject of ongoing research.