What’s Load Got to Do with It?

Space exploration represents one of humanity’s most ambitious endeavors, pushing the boundaries of technology, science, and human endurance. Among the many physiological challenges posed by space travel, its effects on skeletal muscle are among the most significant. The microgravity environment alters normal forces acting on muscles, leading to adaptations with profound consequences for astronauts' health and performance and similar issues for space tourists. What follows is meant to capture the breadth of topics associated with the physiological effects of space travel on skeletal muscle and the underlying mechanisms, distinctions in the profile of professional and casual space travelers, and preparations needed for short- and long-term human space exploration.