Prolonged stays in space for astronauts Sunita Williams and Butch Wilmore have raised health concerns including increased red blood cell destruction, cardiovascular issues, and DNA damage from space radiation. Studies indicate higher mitochondrial DNA levels in their blood upon return. Due to workspace delays, their retrieval might face further postponements as NASA assesses their situation. Prolonged stays in space for astronauts Sunita Williams and Butch Wilmore have raised health concerns including increased red blood cell destruction, cardiovascular issues, and DNA damage from space radiation. Studies indicate higher mitochondrial DNA levels in their blood upon return. Due to workspace delays, their retrieval might face further postponements as NASA assesses their situation. Health and Fitness, Health Tips, Exercises & Workout Tips, Diet & Wellness | Times of India Lifestyle