Studies have shown that the population of some microbes can increase extraordinarily in microgravity and confined spaces. This means many infectious illnesses could easily spread to everyone aboard. The eating equipment, dining area, toilet and sleeping facilities in an orbiter are regularly cleaned to prevent the growth of microorganisms. Garbage and trash are also sealed in plastic bags. Shuttle travelers don't have to do many dishes.
Food containers go into the plastic bags and eating utensils and trays are cleaned with wet wipes.
The orbiter travelers use a toilet that operates very much like the one on Earth. A steady flow of air moves through the unit when it is in use, carrying wastes to a special container or into plastic bags. The container can be opened to vacuum, which exhausts the water and dries the solids, and the plastic bags, when used, can be sealed. Some of the wastes may be returned to Earth for postflight laboratory analysis. In the past, such analyses have helped doctors understand how the body functions in microgravity, including data on which minerals the body loses in unusual amounts.