Living in a state of eternal freefall may be the greatest adventure of all time but being an astronaut may not always be as fun as it looks! An endless amount of somersaults and never having to walk between rooms may sound like pure happiness but what else does living in microgravity affect?
More than half of astronauts experience Space Adaptation Syndrome (SAS) commonly referred to as space sickness. SAS is a result of the human body suffering from spatial disorientation due to the transition into weightlessness. The vestibular system in the inner ear becomes confused by the lack of gravity, and the lack of a defined up and down. The effects can vary from mild nausea and discomfort to vomiting and intense headaches. On the positive side, if you don’t get it the first time you go to space, you probably won’t ever experience it on future trips.
An astronaut vomited in his helmet – Credits unknown
90 minute days
On the ISS you experience a full rotation of the Earth every 90mins meaning that astronauts on board experience a sunrise or sunset every 45mins. Having 16 day-night cycles in a 24 hour period destroys circadian rhythms and therefore many astronauts report difficulty sleeping. To help reduce astronauts experiencing space lag they operate on a 24 hour cycle using Greenwich Mean Time.
Puffy Face/Chicken Leg Syndrome
Puffy face and skinny leg syndrome is also something that is experienced when living in space. This is a result of fluid changes in the body, especially within the first couple of days of entering the microgravity environment. On Earth the heart has to pump blood against gravity, to get blood to the upper half of your body it must work harder. In space there is no gravity to pull fluids down, they remain in the upper half of the body causing puffy face and skinny leg syndrome until the body readjusts.
Microgravity causes an astronaut’s body to change while in space. Credit: NASA
Although it is possible to snore in space and there are recordings of astronauts to prove it, comparisons to their snoring patterns on Earth have demonstrated that snoring is significantly reduced in space.
Cosmic Ray Flashes
Astronauts have reported experiencing blinding flashes of light in their eyes whilst in space. These are even experienced when their eyes are shut. These flashes are actually the astronauts seeing cosmic rays (high energy subatomic particles) passing through their eyes.
Space will also change the shape of your eye. The optic nerve and the back of the eye swell which causes it to change shape. Vision changes experienced by astronauts spending a significant period of time in space have been shown to not be temporary. There is currently not a great understanding as to why these vision changes occur and more investigation needs to occur.
Using the Advanced Diagnostic Ultrasound in Microgravity (ADUM) protocols, ISS Expedition Commander Leroy Chiao performs an ultrasound examination of the eye on Flight Engineer Salizhan Sharipov – Credits: NASA
No crying allowed
You cannot cry in space. Although your eyes are physically capable of producing tears, there is no way for them to fall. Crying therefore consists of a ball of water building around your eye until you wipe it away!
Taste Bud Changes
Your eyes are not the only things that change in space, your taste buds change as well. Astronauts have reported that eating in space is similar to eating when you have a head cold, in that your sense of taste is dulled considerably. As a consequence astronauts commonly prefer spicy food to help .
Gravity is no longer pressing down on your skeleton so you’ll grow taller in space! Due to their vertebrae stretching out Astronauts experience growth of up to 7.6cm (3 inches) in long duration spaceflight. Unfortunately it can’t stay like that forever and when returning to Earth most astronauts return to their regular height within 10 days.
Loss of muscle mass and bone density are two problems which are significant among long term space missions. On long term missions to the ISS astronauts have experienced an average loss of bone density of more than 1% bone mass per month. Ensuring that their diet is rich in calcium as well as vitamin d is one of the main countermeasures to help ensure astronaut bone health. Drugs commonly used for osteoporosis on Earth are also used to help reduce loss of bone mass.
Muscle atrophy is also experienced by astronauts due to the lack of gravity. Muscle mass loss is significant among long stay astronauts due to the lack of need to use muscles to perform tasks in space. Although they are not needed in space, when astronauts return to earth they are not capable of standing or walking due to the amount of muscle they have lost. Loaded exercise for a minimum of two hours a day in space is the primary method to reduce muscle mass loss along with a nutritious diet.
The proprioceptive system becomes a little confused in the microgravity environment. The proprioceptive system is the system of nerves which helps us interpret where our limbs are without having to look around to see them. Gravity pulling down on our joints and muscles is a contributor to how the system interprets where our bodies are. As a result astronauts often ‘lose’ their arms and legs in space.
You might miss your bathroom
Since if you had a tap or a sink in space water would just fly around everywhere, there is no such thing as a shower. Therefore even if you’re in space for six months or longer the only method you have of cleaning yourself is a nice refreshing sponge bath! Imagine having to exercise for 2 hours a day and not being able to have a shower afterwards! It’s not like you can open a window to let some fresh air in either, so one of the first things astronauts comment on when they enter the ISS is that it does not smell like nice flowers and perfume…
Russian bathroom on-board ISS – Credits : AP press
Upon returning to Earth a problem that is frequently reported by astronauts is dropping of objects and being perplexed when they smash. Even after short stays on orbit it appears to be an easy habit to develop that if you let an object go it will just stay as it is. Some astronauts have even admitted to experiencing this after being back on Earth for months.
Living in space is definitely very different to living on earth and as a fairly new species to outer space we still have a lot to learn about how to effectively live in such an environment, which we will…
Because we are all Born For Space!