Piloted space vehicles have life-support systems designed to meet all the physical needs of the crew members. In addition, astronauts can carry portable life-support systems in backpacks when they work outside the main spacecraft.
Breathing
A piloted spacecraft must have a source of oxygen for the crew to breathe and a means of removing carbon dioxide, which the crew exhales. Piloted space vehicles use a mixture of oxygen and nitrogen similar to Earth's atmosphere at sea level. Fans circulate air through the cabin and over containers filled with pellets of a chemical called lithium hydroxide. These pellets absorb carbon dioxide from the air. Carbon dioxide can also be combined with other chemicals for disposal. Charcoal filters help control odors.
The food on a spacecraft must be nutritious, easy to prepare, and convenient to store. On early missions, astronauts ate freeze-dried foods -- that is, frozen foods with the water removed. To eat, the astronauts simply mixed water into the food. Packaging consisted of plastic tubes. The astronauts used straws to add the water.
Over the years, the food available to space travelers became more appetizing. Today, astronauts enjoy ready-to-eat meals much like convenience foods on Earth. Many space vehicles have facilities for heating frozen and chilled food.
Water for drinking is an important requirement for a space mission. On space shuttles, devices called fuel cells produce pure water as they generate electricity for the spacecraft. On long missions, water must be recycled and reused as much as possible. Dehumidifiers remove moisture from exhaled air. On space stations, this water is usually reused for washing.
The collection and disposal of body wastes in microgravity poses a major challenge. Astronauts use a device that resembles a toilet seat. Air flow produces suction that moves the wastes into collection equipment under the seat. On small spacecraft, crew members use funnels for urine and plastic bags for solid wastes. While working outside the spacecraft, astronauts wear special equipment to contain body wastes.
The simplest bathing method aboard a spacecraft is a sponge bath with wet towels. Astronauts on early space stations used a fully enclosed, collapsible plastic shower stall. This allowed the astronauts to spray their bodies with water, then vacuum the stall and towel themselves dry. Newer space stations have permanent shower stalls.
Sleeping
Space travelers can sleep in special sleeping bags with straps that press them to the soft surface and to a pillow. However, most astronauts prefer to sleep floating in the air, with only a few straps to keep them from bouncing around the cabin. Astronauts may wear blindfolds to block the sunlight that streams in the windows periodically during orbit. Typically, sleep duration in space is about the same as that on Earth.
Recreation
Recreation on long space flights is important to the mental health of the astronauts. Sightseeing out the spacecraft window is a favorite pastime. Space stations have small collections of books, tapes, and computer games. Exercise also provides relaxation.
Controlling inventory and trash
Keeping track of the thousands of items used during a mission poses a major challenge in space. Drawers and lockers hold some materials. Other equipment is strapped to the walls, ceilings, and floors. Computer-generated lists keep track of what is stored where, and computerized systems check the storage and replacement of materials. The crew aboard the spacecraft may stow trash in unused sections of the vehicle, throw it overboard to burn up harmlessly in the atmosphere, or bring it back to Earth for disposal.
Communicating with Earth
Communication between astronauts in space and mission control, the facility on Earth that supervises their space flight, occurs in many ways. The astronauts and mission controllers can talk to each other by radio. Television pictures can travel between space vehicles and Earth. Computers, sensors, and other equipment continuously send signals to Earth for monitoring. Facsimile machines on spacecraft also can receive information from Earth.
Working in space
Once a space vehicle reaches its orbit, the crew members begin to carry out the goals of their mission. They perform a variety of tasks both inside and outside the spacecraft.
Navigation, guidance, and control
Astronauts use computerized navigation systems and make sightings on stars to determine their position and direction. On Earth, sophisticated tracking systems measure the spacecraft's location in relation to Earth. Astronauts typically use small firings of the spacecraft's rockets to tilt the vehicle or to push it in the desired direction. Computers monitor these changes to ensure they are done accurately.
Activating equipment
Much of the equipment on a space vehicle is turned off or tied down during launch. Once in space, the astronauts must set up and turn on the equipment. At the end of the mission, they must secure it for landing.
Conducting scientific observations and research
Astronauts use special instruments to observe Earth, the stars, and the sun. They also experiment with the effects of microgravity on various materials, plants, animals, and themselves.
Docking
As a spacecraft approaches a target, such as a space station or an artificial satellite, radar helps the crew members control the craft's course and speed. Once the spacecraft reaches the correct position beside the target, it docks (joins) with the target by connecting special equipment. Such a meeting in space is called a rendezvous. A space shuttle can also use its robot arm to make contact with targets.
Maintaining and repairing equipment
The thousands of pieces of equipment on a modern space vehicle are extremely reliable, but some of them still break down. Accidents damage some equipment. Other units must be replaced when they get old. Astronauts must find out what has gone wrong, locate the failed unit, and repair or replace it.
Assembling space stations
Astronauts may serve as construction workers in space, assembling a space station from components carried up in the shuttle. On existing space stations, crews often must add new sections or set up new antennas and solar panels. Power and air connectors must be hooked up inside and outside the station.
To sleep aboard a spacecraft, astronauts can zip themselves into sleeping bags strapped to the wall. Blindfolds block the sunlight that streams in the windows periodically during orbit. Image credit: NASA
Recreation on long space flights is important to the mental health of the astronauts. Sightseeing out the spacecraft window is a favorite pastime. Space stations have small collections of books, tapes, and computer games. Exercise also provides relaxation.
Controlling inventory and trash
Keeping track of the thousands of items used during a mission poses a major challenge in space. Drawers and lockers hold some materials. Other equipment is strapped to the walls, ceilings, and floors. Computer-generated lists keep track of what is stored where, and computerized systems check the storage and replacement of materials. The crew aboard the spacecraft may stow trash in unused sections of the vehicle, throw it overboard to burn up harmlessly in the atmosphere, or bring it back to Earth for disposal.
Communicating with Earth
Communication between astronauts in space and mission control, the facility on Earth that supervises their space flight, occurs in many ways. The astronauts and mission controllers can talk to each other by radio. Television pictures can travel between space vehicles and Earth. Computers, sensors, and other equipment continuously send signals to Earth for monitoring. Facsimile machines on spacecraft also can receive information from Earth.
Working in space
Once a space vehicle reaches its orbit, the crew members begin to carry out the goals of their mission. They perform a variety of tasks both inside and outside the spacecraft.
Navigation, guidance, and control
Astronauts use computerized navigation systems and make sightings on stars to determine their position and direction. On Earth, sophisticated tracking systems measure the spacecraft's location in relation to Earth. Astronauts typically use small firings of the spacecraft's rockets to tilt the vehicle or to push it in the desired direction. Computers monitor these changes to ensure they are done accurately.
Activating equipment
Much of the equipment on a space vehicle is turned off or tied down during launch. Once in space, the astronauts must set up and turn on the equipment. At the end of the mission, they must secure it for landing.
Conducting scientific observations and research
Astronauts use special instruments to observe Earth, the stars, and the sun. They also experiment with the effects of microgravity on various materials, plants, animals, and themselves.
Docking
As a spacecraft approaches a target, such as a space station or an artificial satellite, radar helps the crew members control the craft's course and speed. Once the spacecraft reaches the correct position beside the target, it docks (joins) with the target by connecting special equipment. Such a meeting in space is called a rendezvous. A space shuttle can also use its robot arm to make contact with targets.
Maintaining and repairing equipment
The thousands of pieces of equipment on a modern space vehicle are extremely reliable, but some of them still break down. Accidents damage some equipment. Other units must be replaced when they get old. Astronauts must find out what has gone wrong, locate the failed unit, and repair or replace it.
Assembling space stations
Astronauts may serve as construction workers in space, assembling a space station from components carried up in the shuttle. On existing space stations, crews often must add new sections or set up new antennas and solar panels. Power and air connectors must be hooked up inside and outside the station.
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