A day in the life of an astronaut

How astronauts do everyday things like visit the bathroom, eat, sleep and exercise in space.

Published Date
17 - Jul - 2013
| Last Updated
17 - Jul - 2013
A day in the life of an astronaut

Search for Commander Chris Hadfield on Google and you will come across news of his team’s recent Earth landing, fascinating space photographs, some quirky videos from inside the International Space Station and so on. We can safely say that no other astronaut has used social media this wisely to create excitement about astronomy, spacecrafts, spacewalks and so on. No wonder he has almost a million followers on Twitter.

We all know that astronauts carry out a lot of experiments when out in space, plus there is maintenance work to be done on the space station – all in zero gravity. While understanding that is a topic we would love to explore sometime in the future, for the purpose of this story we decided to cover the absolute basics. How do you perform regular everyday tasks in the absence of gravity?


The first thing we do on waking up – at least most of us – is brush our teeth. Some of us do it before sleeping as well. Having a bath is the next logical step. But both these things involve the use of lots of water, something a lot of us take for granted. But up in space, there is a different way of doing things.

Most of the liquids taken inside a spacecraft are carried inside pouches which have a straw attached. You squeeze out water from a pouch just like you squeeze out toothpaste from a tube. Since you do not have access to running water, a couple of drops of water are used to wet the toothbrush. The foam residue generated due to brushing cannot be spit out as there is no gravity here to drain it. So you either wipe off the foam on a disposable cloth or like most astronauts – swallow it!

Taking a shower is again out of the question, as water will just float in microgravity and won’t really fall on your body or drain out. So the next best way to clean up is using a damp cloth. Special kind of rinseless shampoos are employed inside a spacecraft which generate very little or no foam. Astronauts can shampoo their hair with their clothes on as the shampoo just tends to stick to their hair. They need to gently massage their hair to clean them and then wipe off the shampoo.

Space Potty

Going to the toilet is one ritual all of us go through on a daily basis, the process helped in a major part by gravity. In a microgravity environment, you can just imagine the difficulty in performing this task and of course you just cannot use the same terrestrial implementations to deal with poop and urine. Enter a special Space Commode!

A space commode (photo by Daniel Djang courtesy Discover Los Angeles)

The commode appears different from the ones seen on earth. For starters, they have a base to hold your feet in position and thigh restraints to hold you in the seated position. In case you want to urinate standing up, you have toe-bars under which you slip in your feet. The commode opening is minor when compared to the western style commodes we are used to and there is a separate pipe with a funnel-like implement at its mouth for urination. The commodes have a suction mechanism to suck all the waste material. So the flush is basically flowing air ( instead of water) which pulls the waste away from the astronaut’s body.

You need to make sure that you aim right. Trainee astronauts who are not very sure of their ‘alignment’, have a ‘Positional Trainer’ commode, which resembles a real space potty with one minor addition – the trainer has a camera placed within, which is hooked up to a monitor using which the trainee can adjust his/her seating alignment! There are a variety of disinfectant wipes available to wipe up once the business is done.

But what happens during a spacewalk? Well, according to Cmdr Hadfield, astronauts on spacewalks use special ‘absorbent undergarments’ like an adult diaper, to take care of waste.

The next logical question that may be bothering you is, ‘How is the waste disposed?’ All solid waste is completely dried with the moisture removed, compressed and kept in an on-board storage container. It is then disposed off when the spacecraft lands on earth. As for liquid waste, it is either sent into space or on the International Space Station it is recycled through a special water treatment plant and turned back into drinking water (Eew?!)


Food carried inside a space shuttle has to meet certain requirements. Carrying packaged food such as the type available in supermarkets is not an option, as the food needs to be stored for longer periods of time. Care also has to be taken that the food does not become a breeding ground for bacteria and fungi. Since moisture is the primary cause for micro-organism growth, the food packets found inside a space shuttle are partially or completely dehydrated. Meats are exposed to radiation to give them a higher shelf life. Forget using salt, pepper and other condiments in their natural state inside a spacecraft. In a microgravity environment crumbs and particles floating around can be hazardous.

So each food packet will have dehydrated food with a small opening which goes into the water dispensing station which dispenses hot or cold water so that the food can be rehydrated.The ISS also has forced-air convection ovens to warm rehydratable, thermostabilized and irradiated food items. All drinks are imbibed through a straw to prevent liquid from escaping.

Astronauts are given an eight-day menu decided by the space agency, which contains balanced meals with a calorie count of 1900 to 3200 calories per day depending on the weight and gender of the astronaut. Of course, the astronauts do get the option to carry some of their favourite food items which goes in the bonus containers, provided it is suitable inside a spacecraft.

As you must have realised by now, most of the food consumed on a spacecraft is sticky in nature. Also, food aromas cannot really be smelt in zero gravity which in turn affects taste. Most food tastes bland - at least till the time the astronauts blood flow is regularised (as blood tends to be pushed to the brain which fills up the sinuses and affects sense of smell and taste).


On earth we are always working against gravity which keeps our muscles and bones in good condition as they are constantly being used. But in space in a zero gravity scenario, bones and muscles aren’t really being put to as much use. As a result, bone density drops and you tend to lose muscle mass as they are no longer employed to support your weight.

Exercising inside a space shuttle is not just a lifestyle decision, but mandatory to keep the bones and muscles in working condition. Astronauts have to be healthy to carry out work on the space station which includes spacewalks. On the ISS, the astronauts are expected to exercise for two hours daily and their exercise routine is monitored and can be adjusted according to data from daily exercise routine.

Astronauts use a treadmill (which has a harness system to secure the astronaut) for cardiovascular exercise, maintaining neuromuscular patterns for locomotion and a cycle ergometer which is like your stationary bicycle for cardiovascular exercise. The Advanced Resistive Exercise Device (ARED) uses vacuum cylinders which apply loads of up to 600 pounds to allow astronauts to simulate weight-lifting exercises in space.

The Advanced Resistive Exercise Device

All the exercise equipment comes with a vibration isolation system, to prevent astronauts who are working out from disturbing others on-board.

Some enterprising astronauts such as Sunita Williams have even completed a triathlon in space.


In zero gravity, where you float most of the time, sleeping can seem like a task. For starters, you have no need for mattresses or pillows here. On the International Space Station there are six sleep-pods, each of which contains a sleeping bag tied to the wall. All the astronaut has to do is get in them, zip up and float to sleep.

Astronauts using specially made sleeping bags in space (image courtesy NASA)

One thing to note with the ISS is that it witnesses a sunrise every 90 minutes, so the circadian rhythms that we are used to on earth, go for a toss in space. Also the constant whirring noise heard inside a space station can be distracting. The astronauts are provided with earplugs and eye-masks to drown out the noise. Most astronauts are used to taking sleep-promoting medications. Although 8-8.5 hours is the preferred sleep duration, most astronauts have reported that they just need 6-6.5 hours to feel fully rested. NASA also has a tradition of Wakeup Call songs that are played regularly. And just in case you were wondering, yes, it is possible to snore in space. 

To sign off, here’s Chris Hadfield’s rendition of David Bowie’s ‘Space Oddity’...IN SPACE!!!

Nimish SawantNimish Sawant

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