It is inevitable that medical conditions of varying complexity, severity and emergency will occur during spaceflight missions with human participants. Different levels of care are required depending on the problem, available resources and time required to return to Earth.
All medical problems have the potential to affect the mission, but significant illnesses or trauma will result in a high probability of mission failure or loss of crew. As the distance that missions travel from Earth increases, more possible medical conditions and types of trauma need to be evaluated.[by whom?] Return to Earth will be highly unlikely or very difficult depending on the distance traveled.[not verified in body] Emergency health care will, and psychological support may, have to be self-administered and could possibly be completely autonomous. The most effective way to provide adequate support is to establish a thorough pre-flight health status assessment and develop a systematic approach to autonomous health care in space.[1]
For NASA, specific provisions and requirements for medical services during space missions are outlined in NPD 8900.5B NASA Health and Medical Policy for Human Space Exploration, NPD 8900.1G Medical Operations Responsibilities in Support of Human Space Flight Programs and NASA-STD-3001 NASA Spaceflight Human Systems Standard - Volume 1, Crew Health.