Long duration space missions: Challenges and prospects in sustaining humans in space

The space environment presents extreme conditions for the human body. Exposure to such challenging conditions may lead to both short- and long-term health problems. Microgravity and ionizing radiation levels are two major stressors influencing humans in space. Non-terrestrial gravity imposes deleterious effects on human physiology, thereby creating obstacles for long-term space missions. This review explores how microgravity and space radiation influence the physiological well-being of space travelers. Molecular and systemic effects of these stressors on gastrointestinal, cardiovascular, neuro-ocular, and musculoskeletal systems have been discussed. Moreover, the countermeasures in vogue such as exercise, nutrition, and pharmacological interventions, which are critical for maintaining astronaut health have been documented. Additionally, this review highlights the role of cutting-edge health technologies in space sciences research, offering a visionary approach for monitoring, prevention, and treatment of spaceflight-induced disorders. Finally, the review presents a vision, emphasizing the relevance of the current state-of-art from a futuristic perspective, where extreme conditions necessitate enhanced physiological resilience and human performance optimization. Tapping such strategies can help in improving the health, adaptability, and endurance of humans during long-term space missions.