Robert W. Mellette
In the early flights of the Mercury spacecraft, the management of human waste was achieved primarily through proper pre-flight diet. This was a suitable arrangement for short duration flights, but as the flight time in space was extended, the need for a reliable, sanitary and efficient system of waste management became a necessity.
Today, a sophisticated system collects and processes biowaste from both male and female crew members aboard the Space Shuttle. In addition to urine and feces, Shuttle systems remove or store exhaled carbon dioxide, perspiration, waste water, garbage and food packaging materials.
The Waste Collection System (WCS) or toilet aboard the Space Shuttle is surprisingly earth-like. The most visible difference is the addition of a waist belt and foot restraints required to keep the user “‘in place”’ during use. A second major difference from an earth system is that the Shuttle’s toilet utilizes an air suction in the place of gravity to carry waste away from the user. The fecal matter and sanitary tissue are shredded by high speed tines and thrown off to the sides of a cylindrical storage tank. After operation, the storage tank is opened to the vacuum of space which dries the waste. Some of the waste may be used for post-flight analyses. In the past, such analyses have enabled doctors to determine which minerals are lost excessively in space, which helps to increase our understanding of bodily functions. Urine is collected with the user either standing or sitting on the commode. A contoured body cup provides a good seal with the female crewmember’s body. Liquid wastes are stored in a waste water storage tank. A filtering system removed bacteria, dirt and odors.
Located in the mid-deck area of the Shuttle is a personal hygiene station. Health is an important factor in a successful Space Shuttle mission. To guard their health, the astronauts must keep clean. Earlier experiments aboard Skylab demonstrated the difficulties associated with astronauts taking showers. In the weightlessness of space, water drops would fl oat around in the cabin. Shuttle astronauts do not take showers, they take sponge baths to keep clean. Water and soapsuds stick to the skin in space, so a dual washcloth arrangement works best. One washcloth is used for washing and a second for rinsing. In the forward mid-deck cabin area each astronaut has a personal hygiene kit. These kits provide each crewmember with articles for dental hygiene, haircare, nailcare and shaving devices.
The management of trash is accomplished by routine stowage and daily collection of wet and dry trash. The bulk of this trash consists of expended wipes, tissue and used food containers. To facilitate clean up a liquid biocidal cleanser is used. This cleanser is sprayed onto surfaces such as the Waste Collection System, the dining area and on the floors and walls when required. Disposable plastic gloves are worn while using this biocidal cleaner and general purpose dry wipes are used to wipe us the sprayed area. Sanitation is very important within the confines of the Shuttle cabin. Studies show that some nicrobes increase their population at a dramatic rate in the weightless environment of the Shuttle’s cabin. If these microbes were not controlled, it is possible that an illness could spread to everyone on board. A vacuum cleaner is provided for general housekeeping duties.
