Sanitary Facilities

views updated

Sanitary Facilities

The first American to travel into space, Alan Shepard, had been lying on his back in the Mercury capsule he had named Friendship 7 for over 4 hours. Technical problems had delayed the launch, and Shepard was beginning to experience uncomfortable pressure in his bladder. National Aeronautics and Space Administration (NASA) engineers had not anticipated that Shepard would spend such a long time in the space suit, and so the suit had no provision for dealing with bodily waste. In desperation, Shepard requested permission from the engineers to urinate in the space suit. The engineers and doctors conferred briefly and decided it was safe to do so. Friendship 7 lifted off on May 5, 1961.

Since that first historic flight the bathroom facilities on spacecraft have improved substantially. On the next flight Gus Grissom wore a large diaper that had been quickly devised by NASA engineers and medical consultants. This arrangement subsequently evolved into a large plastic bag contraption designed to accept and contain solid waste as well as liquids. The bag attached directly to the astronaut's buttocks with sticky tape and did not always work as it was supposed to.

For extended space walks and surface excursions, space suits are still equipped with diapers or waste bags. However, for longer missions when the suit is not worn, better and more convenient sanitary facilities are required. All modern spacecraft designed for extended stays in space include personal hygiene and toilet facilities.

Studies have shown that bacteria and fungi can multiply rapidly in a spacecraft cabin. This was an issue on the Mir space station and other spacecraft. To avoid this problem, food preparation, dining, toilet, and sleeping areas are cleaned and disinfected regularly. Disposable clothing is worn for 2 or 3 days and then discarded. The clothing is then sealed in airtight plastic bags and stored in lockers. After meals, empty food containers are sealed in airtight plastic bags that are also stored. All this trash eventually is returned to Earth.

Current Facilities

Although it may be possible to skip a shower or shampoo for a flight of a day or two, astronauts are usually required to spend several days or even weeks in space. During that time they must wash their hair, brush their teeth, shave, and go to the bathroom. When astronauts brush their teeth, they may have to swallow the toothpaste or spit into a washcloth. Shaving, whether the astronaut uses a conventional or an electric shaver, is done much as it is on Earth. Astronauts use a thick shaving cream that can be wiped off without rinsing. Their electric shavers use a slight flow of air to capture the shaved hairs.

There is no shower on the space shuttle, and so astronauts use a damp sponge or washcloth and soaps that do not need to be rinsed off. For privacy, they draw a curtain across a portion of the galley. The bathroom is equipped with a washbasin that dispenses warm water, a soap dispenser, a mirror, and a reading light. Clips on the wall hold towels, washcloths, and other personal items. Since water and soap suds stick to the skin in a weightless environment, little water is needed to wash. There is even a window so that the astronauts can get a view of space.

Each space shuttle has a toilet, officially designated the Waste Collection System, that can be used by both men and women. It was designed to be as much as possible like those on Earth. However, in the weightless conditions of space, flowing air substitutes for gravity to move waste through the system. The shuttle toilet is in its own room in the crew compartment. Every attempt was made to make the toilet resemble and function like a conventional toilet on Earth. Of course, in the freefall conditions of orbit, astronauts must strap themselves into place, using a bar across the thighs or hook and loop straps. The commode seat is made of a pliable material that provides a good air seal to the buttocks. Solid waste is collected in a bag. When the astronaut is done, a valve is opened, exposing the solid waste to the vacuum of space. This instantly freeze-dries the waste, which is then collected, stored, and returned to Earth for chemical and biological analysis.

The shuttle urinal can be used by female and male astronauts. It consists of a flexible tube that can be attached to a funnel. Each astronaut is provided with a personalized and fitted funnel. The urinal also works by substituting air flow for gravity. The urine is collected and stored in a waste tank, and the air is filtered, sanitized, and recycled. The tank is emptied periodically by venting to space.

The Future

When the Environmental Control and Life Support System (ECLSS) is delivered to the space station (scheduled for October 2005), the waste collection system on the space station will be much more complex and sophisticated than the system used on the shuttle. Because the International Space Station (ISS) is designed for long-term stays, all water will be collected and recycled, including water vapor in exhaled air and the water in the urine from humans and laboratory animals. In the urine recycling system large solids and trash are removed with a filter similar to a coffee filter. The liquid then passes through a multilayer filtration system that removes organic and inorganic materials. Finally, the water passes through the "catalytic oxidation reactor," which removes volatile organic compounds and kills bacteria, viruses, and other microbes.

The ELCSS will allow astronauts to take real showers for the first time. The module contains a watertight compartment with a handheld spray nozzle. After the shower, astronauts will use another hose to vacuum up any excess water before leaving the compartment. Although better than a damp washcloth, it will not be a luxurious hot shower. It will use about 4 liters of water, compared to 50 liters for a shower on Earth.

see also Human Factors (volume 3); Living in Space (volume 3).

Elliot Richmond