Is there a doctor in the house? The Role of a Flight Surgeon

What is a Flight Surgeon?

Canadian Space Agency (CSA) flight surgeon, Dr. Jean-Marc Comtois, provided medical support to CSA astronaut Marc Garneau during extravehicular activity (EVA) training at the National Aeronautics and Space Administration (NASA) Neutral Buoyancy Laboratory in Houston, Texas in preparation for mission STS-97.

A flight surgeon is not actually a surgeon, but rather a doctor with training and experience in aviation and space medicine. Flight surgeons provide medical support for astronauts during training exercises and space missions. Their main role is to make sure that astronauts are physically and mentally fit to participate in these activities. It is also their responsibility to advocate a safe environment for the astronauts on earth or in space. When a medical problem does occur the flight surgeon provides medical care to the astronaut. In the words of Canadian astronaut Chris Hadfield, "the flight surgeon's job is to keep you healthy enough to stay flying."

Astronaut Health

One of the most effective ways to decrease the chance of a medical problem in space is to select and retain healthy astronauts. Flight surgeons play a major role in the selection of new astronauts and in deciding which astronauts should fly on each mission. They set the medical standards that people must meet to become an astronaut. These standards are based on the current understanding of the risks of space travel, the effect of micro-gravity on the body, the countermeasures that are available to decrease these effects and the limited medical care that is available in space if a problem should occur. Flight surgeons then use these standards to screen applicants during astronaut selection.

Once new astronauts are selected, flight surgeons conduct physical examinations every year to ensure that the astronauts are medically fit for spaceflight. If astronauts do not pass the annual physical examination, the flight surgeons would work with them to resolve the medical problem and return them to flight status.

When an astronaut is recommended for a space mission, the flight surgeons will ensure that the astronaut is fit for the specific activities on the mission and that the mission will not have negative long-term effects on the astronaut's health.

In the remote circumstance that an assigned astronaut develops a medical problem before the mission, the flight surgeon would only suggest the astronaut be removed from the mission if the problem could worsen during spaceflight, affect the health and safety of the crew or have a negative impact on the mission.

Flight surgeons also sit on medical boards and panels that develop the procedures to keep astronauts healthy and safe in space, and to review these procedures regularly to ensure they include the most recent research findings.

Medical Support for Spaceflight

Since flight surgeons are ultimately responsible for the health and safety of the crew, they need to know the risks associated with a mission and the medical history of each astronaut in order to anticipate possible hazards, minimize danger to the crew, and maximize mission success. Flight surgeons not only rely on their own knowledge, but also on the expertise of the medical support team. This team is made up of biomedical engineers and medical specialists such as psychologists, psychiatrists, exercise physiologists, nutritionists, and radiation health officers. The flight surgeons are the focal point for all medical activities and manage the information they receive from the medical support team to determine how to best respond to each medical situation.


The flight surgeon's main goal before the flight is to ensure that the crew remains healthy and free from injury. Flight surgeons supervise mission planning from a medical perspective, deal with medical problems that affect the crew's ability to train or remain qualified, and familiarize themselves with the mission activities. For example, flight surgeons monitor and may even participate in training to use equipment and perform EVA. This helps to better understand the astronauts' work as well as the physical and psychological stress they may face in space. Since flight surgeons do not fly in space, they train one astronaut as the Crew Medical Officer (CMO) for the mission. The CMO serves as the eyes and ears of the flight surgeons during the mission. If one of the astronauts in the crew was a medical doctor, he or she would normally be designated the CMO. If not, one of the crewmembers would undergo training to perform basic medical procedures.

The flight surgeons ensure that all medical supplies are in place for the flight and that the crew is trained to use countermeasures to decrease the negative effects of spaceflight on their health. The flight surgeons conduct the pre-launch medical tests and support the crew at the launch facility.


The flight surgeon's top priority during spaceflight is to maintain the health of the astronauts. A team of flight surgeons provides 24-hour medical support to the astronauts from the ground at the Mission Control Center. During shuttle flights, flight surgeons hold daily private medical conferences with the crew and the CMO. On longer space station missions, flight surgeons hold weekly private medical conferences with each crewmember, and the CMO performs periodic in-flight medical evaluation for the flight surgeons. On the Space Shuttle, the Soyuz and the International Space Station (ISS), minor injuries and ailments can be treated but there are limited medical capabilities for treating more severe injuries and illnesses. If the flight surgeons believe that a medical condition cannot be treated properly in-orbit, or has a harmful effect on crew health, safety, or performance, they can recommend that the crew return to Earth.


Flight surgeons perform a brief medical examination on the astronauts at the landing site. During the first few weeks following the landing, flight surgeons continue to perform a number of medical assessments to monitor the health of each astronaut. They also oversee the crew's rehabilitation to allow the astronauts to return safely to Earth-based activities and flight status as soon as possible.

Medical Support during Astronaut Training

In addition to providing medical support during missions, flight surgeons provide medical support for astronauts during basic and advanced training. By being involved in training, the flight surgeons also get to know the astronauts and gain a better understanding of the potential medical problems they could face in space. For example, CSA flight surgeons have provided medical support in extreme environments during non-mission training like NASA Extreme Environment Mission Operations (NEEMO).

Career Opportunities

CSA flight surgeon, Dr. Jean-Marc Comtois, checks up on the crew of NEEMO 7, an underwater simulated space mission.

Since aerospace medicine is a small field, there are a limited number of flight surgeon positions in Canada, especially in the space program. Other than at the CSA, government agencies such as the Department of National Defence or Transport Canada, and private companies in the aviation industry, such as major airlines, employ flight surgeons.

Training for flight surgeons is offered in Canadian and international institutions. For more information, visit CSA's Aerospace Medicine Training.