Watch this space: bringing medicine beyond Earth’s boundaries

Since the first manned flight by Yuri Gagarin in 1961, the human race has strived to push the boundaries of manned space travel. Originally driven by curiosity, in more recent years the new goal is to extend the range of human habitat beyond Earth’s limits. This will require extended duration space flights. However, humans evolved in the presence of gravity and Earth’s particular atmosphere. Leaving this protective environment poses a myriad of challenges to the human body, including microgravity, solar proton radiation, prolonged confinement and isolation, absence of natural light and circadian rhythm changes. Key effects identified include loss of bone density and muscle strength, adverse psychological changes and increased cancer risk. Future missions will routinely demand complex and physically demanding tasks, and astronauts will be unable to receive additional resources or communications from Earth in a timely manner. It is essential that effective countermeasures be developed to maintain or enhance human performance in microgravity. Increasing private sector investment in commercial space travel also means that future passengers will be a more diverse population that may be less tolerant to space travel than current astronauts. This increases the likelihood of life-threatening in-flight surgical or psychological emergencies. With current flights including only one crew member with limited medical training, changes will need to be made to medical protocols to ensure mission success, such as prophylactic appendectomies and the inclusion of emergency physicians in future crews.