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Weightlessness -

Astronauts experience nausea during the initial hours in space, despite extensive training. Living in a zero-gravity environment 24/7 requires significant adjustment. Even simple activities like flipping a bag upside down to empty it become futile.

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Floating away -

Every time astronauts want to type messages or enter data on a laptop, they have to Velcro the computer and themselves to a stable surface, otherwise they will float away with every keystroke. Not to mention that objects can also float away unbidden if they aren’t strapped down.

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Correspondence -

If an astronaut wants to phone home, they need only connect to an onboard computer that routes the signal to where it needs to go. However, the distance between the ISS and Earth means that there is often a lag with the communication.

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Breathing -

Surprisingly, even breathing in space is difficult. Gravity is usually responsible for pulling exhaled carbon dioxide away from our heads, but in the weightlessness of space it doesn’t go anywhere. Astronauts can experience carbon dioxide headaches if they don’t move around.

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Sleeping -

Sleeping in space poses difficulties, as astronauts can't lay their heads down. They attach sleeping bags to the floor, walls, or ceiling. The lack of a normal day-night cycle, with the ISS orbiting Earth every 90 minutes, further complicates sleep patterns.

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Keeping track of time -

Time on the ISS is measured in flight days (FD) rather than regular days of the week. This unique timekeeping system can be disorienting. On New Year's Eve, astronauts experience the countdown to midnight 16 times due to the station's rapid orbit.

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Body fluids -

Managing body fluids in space is challenging. For instance, tears don't fall but instead form into sticky balls, and using the toilet requires special suction systems to prevent waste from floating around.

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Space diapers -

While urine on the ISS is typically purified into drinking water, astronauts wear special space diapers known as MAGs (Maximum Absorbency Garment) when they exit the spacecraft, which are then discarded and incinerated upon reentry to Earth's atmosphere.

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Puffy face -

The human body is full of fluids, and Earth’s gravity forces them into the lower half of our body. While in space, bodily fluids tend to float to the head instead, which causes some astronauts to experience round-face puffiness.

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No showers -

Astronauts have to take sponge baths while in space instead of typical showers, since water from a shower would float around the station in clumps and end up damaging the incredibly expensive equipment all over the station.

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Odors -

Due to the lack of gravity (and the lack of open windows), odors can quickly spread in the ISS. Even the smell of usually-innocuous aromas can cause a gag reflex.

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The view -

The Cupola (pictured) on the ISS offers breathtaking views of Earth, including auroras, lightning, and city lights. This perspective profoundly impacts astronauts in a way that is called the "overview effect." Astronauts have been known to change significantly after returning to the surface.

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Sunrises -

Since the International Space Station orbits the Earth at a velocity of 17,500 miles (28,000 km) per hour, astronauts aboard the station can see the sun rise 16 times in a single day. This might sound great, but it probably loses its novelty quite quickly.

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No soda -

Carbon dioxide (the ingredient that makes soft drinks gassy) works differently in space and can be dangerous, which is why you won’t find a soda can anywhere on the ISS.

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Scratching an itch -

Every time an astronaut leaves the spacecraft, they must don a body-sized suit known as an Extravehicular Mobility Unit (EMU). Although these suits protect astronauts from outer space’s harsh environment, there is no way to scratch any itches!

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Sneezing -

Astronauts also have to refrain from sneezing while in their space suits. But if it’s unavoidable, they’re trained to direct their sneeze downward into their collars. After all, there are no windscreen wipers inside the helmet!

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No smoking -

Imagine being permanently confined to economy class on an airplane and being told that smoking is prohibited. That’s what it’s like to live on the ISS, where flames of any kind are strictly prohibited. Although, astronauts probably don’t tend to smoke, since going to space requires them to be incredibly healthy.

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Close quarters -

Living on the International Space Station is quite similar to being cooped up with five flatmates, except astronauts don’t have the luxury of being able to leave the apartment.

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Noise -

Since the ISS is basically one giant machine, there is a constant and never-ending hum emanating from the air circulation, electrical, and heat systems. This becomes particularly frustrating at bedtime, since there is no real quiet aboard the station.

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Muscle atrophy -

Even though astronauts are required to exercise regularly while on board the ISS, the weightlessness means that they will still lose muscle and be unable to stand for weeks after they return to Earth.

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Exercise -

If you don’t like exercising on Earth, then you certainly won’t like it in space! Astronauts are required to exercise for no less than two hours every day.

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Brushing teeth -

Getting rid of any liquid is difficult when there’s no gravity, so astronauts have to swallow their toothpaste instead of spitting it out.

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Washing dishes -

As mentioned, running water cannot be used anywhere on the International Space Station, and so astronauts must use moist sanitizing towelettes if they want to clean cutlery.

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Overtime -

Due to the nature of the job, astronauts are on call 24 hours a day, and can sometimes be relied upon to work for 16 hours on average.

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No repairmen -

If something on the space station breaks, then calling a repairman is certainly not a possibility. After all, the ISS orbits approximately 250 miles (400 km) above sea level. Astronauts must be able to diagnose and repair anything on the station at a moment’s notice.

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Decompression -

Going on a spacewalk is not a simple and quick task. Aside from putting on a hefty suit, astronauts must also follow a strict two-hour and 20-minute decompression protocol before they can head out. This helps them avoid decompression sickness, which is when nitrogen bubbles form in the bloodstream.

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Tongue in cheek -

Interestingly, many astronauts experience a drastic change in taste while in space. Some find that their food is bland and they don’t enjoy once-favorite meals, while others have enjoyed food that they previously disliked.

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Bad hair day -

Since the crew of the ISS can sometimes stay onboard for months at a time, they’re bound to need a haircut at some point. Astronauts use a vacuum while cutting hair to prevent the hairs from floating around the cabin. And there is no specialized hairdresser on board, which means that they must cut it themselves. With each other’s help, of course!

Sources: (NASA) (Business Insider) (New Scientist) (The Royal Institution)

See also: Things that have been left on the Moon

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