How the International Space Station Works

Life Aboard the ISS

Astronaut Sandra Magnus poses with free-floating stowage containers in the Destiny laboratory of the ISS.
Astronaut Sandra Magnus poses with free-floating stowage containers in the Destiny laboratory of the ISS.
Image courtesy of NASA

What's it like to live and work in space? To answer such questions, Expedition 18 flight engineer Sandra Magnus, wrote a series of journal entries about her stay aboard the ISS. She notes one important thing: An astronaut's day is planned well in advance (years actually) by many people on the ground. "Well we have a scheduling program on board that has in it all of the details that we need to know in order to do the day's work. It tells us when we should go to sleep, when we should get up, when we should exercise, when to eat our meals, when and what information we need to do our tasks " [source: NASA, Magnus Journal]. Although this does sound extremely rigid, Magnus notes that there is some flexibility in that not every task has to be carried out at the exact time the schedule dictates.

Microgravity presents a challenging environment. Whether you're sleeping, changing clothes or working, unless it's secured in place, everything in the ISS around you floats. Even something as seemingly simple as getting up in the morning and getting dressed isn't all that simple. Imagine opening up your closet only to have its contents come flying out at you. On getting ready in the morning, Magnus states, "When I take off my PJ's, they float around in the crew quarters until I gather them up and immediately fasten them down behind a band or something. Suffice it to say it is easy to lose things up here!" [source: NASA, Magnus Journal].

After waking up, each astronaut has a post-sleep period to prepare for the day. During this time, the astronauts can shower, eat, exercise and get ready for work. Exercise is important; in microgravity, bones lose calcium and muscles lose mass. So, astronauts must exercise for set times. Magnus preferred to exercise first thing in the morning, alternating daily between the stationary bike and treadmill. Next, there's a morning conference, where they discuss with crew members and ground controllers everyone's duties for the day. After the conference, they set out to work.

For work, astronauts conduct experiments or maintenance. Like most working people, they stop to eat lunch -- but their lunch breaks are a little different. The food on the ISS is mainly frozen, dehydrated or heat-stabilized, and drinks are dehydrated. Astronauts collect food trays and utensils, locate their individually-packaged meal from a storage compartment, prepare the items (rehydrating if necessary), heat the items, place them in the tray and eat. After the meal, they place the used items in a trash compactor, and clean and stow the utensils and trays.

After lunch, the scheduled activities continue. At the end of the work day, there's an evening conference followed by a 2-hour pre-sleep period. During this time, the astronauts eat dinner, complete any unfinished tasks and wind down. According to Magnus, there are plenty of options for filling this 2-hour period, "There is also email, phone calls, news, photos to review, and other activities which occupy this time. Friday is movie night and sometimes Saturday too" [source: NASA, Magnus Journal].