Meeting
basic needs in Space. All missions require living in hostile environment of space.
Therefore certain basic needs have to be fulfilled to provide astronauts with
environment similar to that of earth.These
include:• Breathing - Space is a vacuum and there
is no air out there. For the survival of human beings a suitable composition of
air is required. A continuous supply of oxygen is essential for respiration. A
manned spacecraft uses a gas, which is a combination of oxygen and nitrogen.
This gas is circulated with the help of fans in the cabin. • Pressure - human body must be enveloped
by appropriate pressure .The lack of pressure causes changes in the cardiovascular system, the musclo-skeletal
system and the nervous system. To accomplish this problem
airtight enclosures or capsules where appropriate pressure can be artificially
maintained must always surround the astronauts.• Temperature
control - the
temperature of outer space varies drastically. Therefore the space vehicle is
equipped with a temperature control system to maintain the temperature. The
functions carried out by the system are:•
Distribute the heat evenly•
Get rid of the excess heatThe
temperature aboard the spacecraft is maintained by active methods and passive
methods.•
Active method involves the circulation of fluid to remove heat•
Passive methods use insulating materials and electrical heaters• Eating and
drinking - the
food given to astronauts must be nutritious, easy to prepare and should not be
perishable. Modern spacecrafts are equipped with facilities for heating frozen
foods. Food comes in several forms (dehydrated, low moisture, heat-stabilized,
irradiated, natural and fresh). The orbiter has a galley-style kitchen module,
which is equipped with the following:Food storage compartmentsFood warmersA food preparation area with warm and
cold water outletsMetal trays so the food packages and
utensils do not float awayWater is an
essential requirement. Water is made from liquid oxygen and hydrogen
In the space shuttle's fuel cells. The fuel cells can make 25 lb
(11 kg) of water per hour. The water from the fuel cells passes through a hydrogen separator to
eliminate any trapped hydrogen gas. Excess hydrogen gas is dumped
overboard. The water is then stored in four water storage tanks. On a long
mission water must be recycled and reused. Dehumidifiers are used to extract
moisture from the exhaled air. The recycled water is mostly used for washing
purposes.• Eliminating body
wastes - due
to the micro gravity, collection and disposal of wastes poses a huge problem. A
device resembling toilet seat is used for the collection of wastes. Airflow
provides suction for collection of wastes under the toilet seat. On small
aircrafts funnels are used for collection of liquid wastes and plastic bags are
used for solid wastes. While working in space special equipments are worn for
collection of wastes.