"Significant adverse effects of long-term weightlessness include muscle atrophy and deterioration of the skeleton (spaceflight osteopenia)."
An examination of the effects of spaceflight on human physiology and psychology, including changes to bone density, muscle mass, cardiovascular health, and mental health.
Microgravity: The absence of gravity in space and its effects on the human body, including muscle atrophy, bone density loss, and fluid shift.
Radiation exposure: The exposure of astronauts to high levels of radiation during spaceflight and the risks associated with it, including cancer, genetic mutations, and compromised immune systems.
Psychological and social factors: The psychological challenges of long-duration spaceflight, including isolation, confinement, and the psychological impact of space travel.
Nutrition and exercise: The importance of maintaining a healthy diet and regular exercise to counteract the negative effects of space travel on the human body.
Medical emergencies: The challenges of providing medical care to astronauts in space and the role of telemedicine in treating medical emergencies in space.
Human factors and engineering: The design of spacecraft and space habitats to accommodate human needs and the challenges of living and working in space for extended periods.
International collaboration: The importance of international collaboration in space exploration and the sharing of data and research findings related to the impact of spaceflight on human health.
Environmental monitoring: The need for continuous monitoring of the space environment for potential hazards to human health, including radiation, micrometeoroids, and space debris.
Astronaut selection and training: The selection criteria and training requirements for astronauts to prepare them for the physical and mental challenges of spaceflight.
Future considerations: The future of human space exploration and the potential impact on human health of long-duration missions to the moon, Mars, and beyond.
Bone Loss: Extended exposure to microgravity can lead to the loss of bone density and mass, which can result in an increased risk of fractures and other skeletal diseases.
Muscle Loss: Similar to bone loss, microgravity can cause muscle atrophy or muscle degeneration in astronauts, particularly in the critical postural muscles.
Cardiovascular Changes: Astronauts returning from space have shown a decrease in overall heart strength, as well as an increase in blood volume, which can lead to orthostatic hypotension upon returning to Earth.
Vision Impairment: A significant number of astronauts have experienced visual changes during and after spaceflight, including swelling of the optic discs, elongation of the eyeball, and changes in the shape of the cornea.
Radiation Exposure: Astronauts are exposed to higher levels of radiation than those on Earth, which can negatively impact the immune system, increase the risk of cancer and damage to the central nervous system.
Neurological Changes: Changes in brain structure and connectivity have been observed in astronauts after prolonged exposure to microgravity, which can have implications for motor skills, cognition, and behavior.
Immune System Suppression: Spaceflight can alter the functioning of the immune system, making astronauts more susceptible to infections and illnesses.
Fluid Shifts: Changes in fluid distribution and regulation can occur in the gravity-free environment of space.
Mental and Behavioral Health: Isolation, confinement, and separation from loved ones can be a significant source of stress for astronauts, leading to mental and behavioral health issues such as anxiety, depression, and sleep disturbances.
Metabolic Changes: Astronauts often experience metabolic changes due to the unique environmental stressors of spaceflight, including weight loss, changes in nutrient absorption, and hormonal imbalances.
"A slowing of cardiovascular system functions."
"Decreased production of red blood cells (space anemia)."
"Balance disorders."
"Eyesight disorders."
"Changes in the immune system."
"Fluid redistribution (causing the 'moon-face' appearance typical in pictures of astronauts experiencing weightlessness), loss of body mass, nasal congestion, sleep disturbance, and excess flatulence."
"NASA refers to the various deleterious effects of spaceflight on the human body by the acronym RIDGE (i.e., 'space radiation, isolation and confinement, distance from Earth, gravity fields, and hostile and closed environments')."
"The engineering problems associated with leaving Earth and developing space propulsion systems have been examined for over a century."
"This question requires input from the physical and biological sciences and has now become the greatest challenge (other than funding) facing human space exploration."
"A fundamental step in overcoming this challenge is trying to understand the effects and impact of long-term space travel on the human body."
"In October 2015, the NASA Office of Inspector General issued a health hazards report related to space exploration, including a human mission to Mars."
"On 12 April 2019, NASA reported medical results, from the Astronaut Twin Study, where one astronaut twin spent a year in space on the International Space Station, while the other twin spent the year on Earth, which demonstrated several long-lasting changes, including those related to alterations in DNA and cognition, when one twin was compared with the other."
"In November 2019, researchers reported that astronauts experienced serious blood flow and clot problems while on board the International Space Station, based on a six-month study of 11 healthy astronauts."
"The results may influence long-term spaceflight, including a mission to the planet Mars, according to the researchers."