Space agencies, such as NASA, are extremely cautious about any illnesses before they send astronauts into space. Anything from swine flu to the common flu can be disastrous to any crew members as the microgravity weakens the immune system, making the illness much more prominent. The common cold, for example, can have such an impact that congestion can cause ears to become blocked, especially with the changes in pressure that are required on a spacewalk.
As a result, astronauts are kept in quarantine before they are due to travel into space. Additionally, to check for any pre-existing bugs, astronauts must undergo a physical exam. This includes swabs and other lab tests over a week before launch. After the initial exam and seven days before takeoff, the astronauts’ contact with other people is limited. This stage of the quarantine process is strict and even the crew surgeon who is running the tests is also isolated with the crew. Anyone found to be ill right up until the moment an astronaut suits up on launch day are prohibited from working with their crew mates.
However, despite such rigorous tests, astronauts have gotten sick in the past. Apollo 7’s Wally Schirra (pictured above) came down with a cold in the middle of his mission. Other astronauts such as Frank Borman of the Apollo 8 mission, Hans Schlegel and astronauts onboard the International Space Station have also fallen ill, but this is mainly due to their bodies trying to adjust to microgravity.
Image courtesy of NASA