SOZH – life support
Water, food and sanitation come under the acronym of SOZH, СОЖ – Life Support Systems – and are part of the primary life support system located in Zvezda. All are monitored and controlled by the on-board computer system, the laptops providing a crew interface with these.
Sanitation (SGO, СГО) is described on a separate page.
Food
Three daily meals plus a snack are consumed from pre-packaged foods. Packages requiring heating are placed in the electric food warmer set in the galley table in Zvezda, which contains a number of cells for heating food. Both Russian and American rations are supplied.
There is a wide and delicious variety of foods available (an important psychological booster for long-duration crews). An Aerovit multivitamin tablet is taken during the first two meals.
Fresh fruit and other treats are brought up via a Progress cargo flight; they have to be eaten within the first week or so as there is no means of long-term storage. There was supposed to be a refrigerator on board, but I don’t think it is there yet.
Like everything else on the ISS, the crew’s food intake is monitored. Details from an On-Orbit Report:
OOR 24 June 2005
The FE also filled out the regular weekly FFQ (food frequency questionnaire), his eighth, which keeps a log of his nutritional intake over time on special MEC (medical equipment computer) software. (With the updated MEC software, John is using his personalized file that reflects the food flown for his Increment. The FFQ records amounts consumed during the past week of such food items as beverages, cereals, grains, eggs, breads, snacks, sweets, fruit, beans, soup, vegetables, dairy, fish, meat, chicken, sauces & spreads, and vitamins. IBMP [Institute of Biomedical Problems]-recommended average daily caloric value of the crew’s food intake is 2200-2300 cal. If larger quantities of juices and fruits are taken into account, the value can go to 2400-2500 cal.)
Below is an example of a 10-day meal plan, this for Valerii Tokarev of Expedition 12. A key to the food preservation type abbreviations is given below.
- B
- Beverage
- I
- Irradiated
- IM
- Intermediate Moisture
- NF
- Natural Form (i.e. unprocessed)
- R
- Rehydrated
- T
- Thermostabilized
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- More details (LSS ISS)
- NASA Press Kits: “A Taste of Space”. Details of meals on the ISS.
Water
There are two different systems of water supply:
- The water delivered by the Progress is pumped into the «Родник», Rodnik storage system in Zvezda. It provides the crew with potable water from two water tanks and is purified with silver ions (this is incompatible with the American water supply, brought up by the Space Shuttle).
- The Atmospheric Condensate Water Regeneration System: this also generates potable water, collected from the atmosphere via condensation on the cold surfaces of the TCS heat exchangers. It is processed and purified into potable water. The water is accessed by the crew through two valves on the BRP, БРП, heating unit. The water was supposed to be hot or cold, but is in fact hot or warm – cold water is obtained by leaving a filled drinking bag in a cooler part of the ISS.
An interesting fact is that the Russian and American segment water supplies can’t be mixed. The U.S. water uses iodine for bacteria control, while the Russian water uses silver. If these substances mix, a silver-iodine precipitate forms in the water, which may clog the sublimator in the NASA EMU spacesuit.
Photo gallery
View of the galley table in Zvezda (affixed to the starboard side of the Service Module interior). The water dispenser is on the wall behind.
Bill McArthur (ISS-12) demonstrates how to add potable water to a soft beverage package.
ESA astronaut André Kuipers near Russian and American food storage boxes located on the rear panel next to the port kayuta (cabin). They are numbered for Expeditions 7 and 8, the contents listed in English and Russian.
Links
- ECLSS (external link, 393 KB). Page illustration from the Reference Guide to the International Space Station PDF.
- Spaceref: Space Station User’s Guide: Operations. Various PDF documents to download, including operations manuals for Zvezda.
