You won’t think twice when you have to sneeze on earth other than ensuring you don’t sneeze in someone’s general direction. What about up in space? Is it the same as sneezing on earth or is there greater danger involved? As on veteran spacewalker put it, sneezing in a spacesuit can make a proper mess of everything.
As Dave Wolf, six-time spacewalker put it, astronauts can’t stop themselves from sneezing inside their suits and to be honest there really is no way to blow your nose either. Dave further explains that the only cure for this situation is to practice and have a good aim. It is in fact a part of their training! Fact is, no one really wants to sneeze straight at their spacesuit helmet.
The trick therefore is to sneeze low, off the general direction of the windshield. This ways, your view is not messed up.
What about in the general confines of the spaceship? What happens when all three astronauts get sick at the same time? Such an incident has already happened back in 1968. The entire crew of Apollo 7 actually happened to fall sick simultaneously as they tested out a command module in Earth’s own orbit. All three astronauts came down with head colds and the situation got so bad that they decided not to wear their helmets as they prepared for re-entry.
Why We Sneeze
Let’s first understand why we sneeze. This is a general situation and it has nothing to do with how we are feeling. The nose has tiny bit of hair all over the nostrils called cilia. Their only job is to filter out any kind of foreign body that might try and creep through the nostrils. At times, some of the irritants get through the defences of the nose and immediately a signal is sent to the brain that contracts the chest, tightens the throat and shuts the eyes plus mouth. That’s when we sneeze and remove the escaped irritants.
Now, unfortunately, in space sneezing can be dangerous because you do that in a closed environment where there is no way to recycle and circulate air other than what you take from earth. Basically, space stations are a perfect microgravity petri dish.
Back on earth, when a person coughs or sneezes, germs fly from the mouth up to 3 or 6 feet in the air before gravity brings it down to the ground. In space however, germs stay suspended for a really long time and when they do settle, they tend to fall on utensils, toilet seats, instruments and equipment. Besides, microgravity is known to weaken immune systems and these two factors make it much easier to catch sickness from these germs.