I've always been oddly fascinated by the mundane side of
space travel — not the launches or the spacewalks, but the genuinely weird
logistics of daily life. How do you take a shower with no gravity to make the
water fall? How do you sleep without a bed? I finally sat down and dug through
what NASA, ESA, and JAXA have actually published about it, and the answers are
stranger and more clever than I expected.
Sleeping: 16 Sunrises a Day Makes This Genuinely Hard
Here's the problem astronauts face that most of us never
have to think about: the International Space Station orbits Earth roughly every
90 minutes, meaning the crew experiences 15 to 16 sunrises and sunsets every
single day (ESA;
Astronoo).
Human circadian rhythms are hard-wired by millions of years of evolution around
a single 24-hour cycle, so astronauts stick to strict fixed work and sleep
schedules regardless of how many sunrises happen outside the window — otherwise
crews would end up living in a permanent state of jet lag (ESA).
Even with a fixed schedule, sleep is shorter and lower
quality than on Earth. Astronauts sleep an average of just 5-6 hours per day,
compared to the 7-8 hours most of us get on the ground (Science
in School), and some sources put the average closer to 6 hours specifically
because noise from fans and the station's constant movement interrupts rest (Astronoo).
The mechanics of actually sleeping are where it gets
genuinely strange. With no up or down in microgravity, astronauts sleep by
zipping themselves into a sleeping bag tethered to a wall in a small private
crew cabin, specifically to avoid gradually floating away or drifting into
equipment during the night (JAXA; Science
in School). Choosing a sleep spot even matters for safety — it needs to be
positioned in line with a ventilation fan, since free-floating limbs could
otherwise drift into and block the air tubes that circulate the cabin, risking
a dangerous buildup of carbon dioxide in one localized spot (Science
in School).
The background noise is constant and significant. Some
astronauts have compared living on the station to sleeping inside a giant
vacuum cleaner, and many use earplugs, though most eventually acclimatize the
same way people get used to living on a busy street (ESA).
Eating: Dehydrated Food, No Fridge, and a Weakened Sense
of Taste
There's a detail here I found genuinely surprising:
astronauts don't taste food nearly as well in space. Blood flows slightly more
toward the head in microgravity, which mildly congests the nose — as a result,
many astronauts develop a preference for strongly spiced or flavorful food just
to actually taste anything (Astronoo).
The ISS has an oven for reheating meals but no refrigerator
at all (Science
Times). Most food is dehydrated to save weight and space, and astronauts
add hot or cold water to rehydrate it before eating, while some items like
fruit, nuts, and bread are ready to eat as-is (JAXA).
The current space food menu includes more than 300 different items (JAXA)
— a considerable step up from the early 1960s, when the first space food was
limited to bite-sized solid cubes or tubes resembling baby food (JAXA).
Today's ISS astronauts eat things like bacon sandwiches and hot coffee, and
even receive occasional fresh fruit deliveries that serve as both a vitamin C
source and a genuine psychological boost — a small reminder of home (BBC
Sky at Night).
Drinking is its own challenge. Liquids don't pour in
microgravity — they form floating bubbles instead — so astronauts drink through
special straws connected to sealed bags to keep water or juice from escaping
into the cabin (Astronoo).
Even condiments are adapted: salt and pepper are only available in liquid form
on the ISS, since loose granules would simply float away and could damage
equipment or get inhaled (Tech
Times).
Water itself is treated as an extremely precious resource.
Transporting it to the station is expensive, so life-support systems recycle
water from condensation, sweat, and even purified urine, and astronauts drink a
total of about 2.7 kg of water a day drawn largely from this recycled supply (ESA;
Astronoo).
Showering: There Isn't One
This is the detail that surprises most people, myself
included. There are no baths, showers, or washstands anywhere on the ISS (JAXA).
If you turned on a faucet in microgravity, the water wouldn't fall — it would
fly off in every direction and potentially damage sensitive equipment (JAXA).
Instead, astronauts wash using liquid soap, water, and
rinseless shampoo applied with wet wipes and towels (Smithsonian,
via Science Times). For hair specifically, astronauts massage in a small
amount of waterless shampoo, then wipe it away with a towel, with any stray
water immediately suctioned up with a small hose so it doesn't drift through
the cabin (Astronoo).
Non-foaming toothpaste is preferred for the same water-conservation reason, and
astronauts either swallow it or spit into a towel rather than rinsing at a sink
(Science
in School; Astronoo).
Their first real shower, in the traditional sense, comes only once they've
returned to Earth (Science
in School).
Clothing gets the same water-conscious treatment. Since
there are no washing machines on the station, astronauts wear disposable
clothing and simply replace items roughly every three days rather than washing
anything (ESA).
The Bathroom Situation: A $23 Million Toilet
Yes, there's a real toilet on the ISS, and it's genuinely
one of the more engineered pieces of equipment on the entire station. NASA
spent $23 million in 2018 on a specifically designed vacuum toilet for the
station (Science
Times). Officially called the Universal Waste Management System, it uses
airflow instead of gravity to pull urine and solid waste away from the body,
since gravity simply isn't available to do that job for it (BBC
Sky at Night). Astronauts press a funnel closely against their skin for
urination, which is then processed and largely recycled back into drinking
water, while solid waste is collected, compressed, and stored for disposal
since it isn't recyclable in the same way (ESA;
Science
Times).
The Part That Surprised Me Most
What struck me most researching this wasn't any single fact,
but how much deliberate engineering goes into replacing things we do entirely
without thinking on Earth. Gravity does an enormous amount of invisible work
for us — pulling water down a drain, keeping us in bed, letting salt fall out
of a shaker — and every one of those small, automatic processes has to be
redesigned from scratch the moment gravity is taken away. Astronauts aren't
just doing their jobs up there; every single day, they're also quietly solving
physics problems just to eat breakfast and brush their teeth.
