"6_2_13.TXT" (6394 bytes) was created on 10-22-89

SPACE SHUTTLE WASTE COLLECTION SYSTEM
 
     The Space Shuttle Waste Collection System (WCS) is an
integrated multifunctional system primarily utilized to
collect and process biowastes from male and female
crewmembers in a zero gravity environment.  The system is
used as a standard Earth-like facility, and performs the
following general functions:
 
     * Collects, stores, and dries solid wastes
     * Processes urine, and transfers it to the waste water
       tank
     * Processes Extravehicular Mobility Unit (EMU)
       condensate water from the airlock, and transfers it
       to the waste water tank
     * Provides an interface for venting trash container
       gases overboard
     * Provides an interface for dumping Air Revitalization
       System (ARS) waste water overboard in a contingency
       situation
     * For flights when the galley is flown, processes wash
       water from the Personal Hygiene Station (PHS) and
       transfers it to the waste water tank
 
     The Waste Collection System is located on the middeck
of the Orbiter.  A door is provided on the waste management
compartment.  Two privacy curtains are attached to the
inside of the WCS compartment door to provide privacy for
the crewmember.  The door serves as an ingress platform
during prelaunch (vertical) operations, since the flight
crew must ingress over the waste management compartment to
enter the flight deck.  The door has a friction hinge, and
must be open when the WCS is used on-orbit.
 
     The WCS consists of six major components as listed
below:
 
     * Commode
     * Urinal
     * Fan Separators
     * Odor/Bacteria Filter
     * Vacuum Vent QD
     * WCS Controls
 
     The commode contains a single multi-layer hyrophobic
porous bag liner for collecting and storing solid waste.
When in use, the commode is pressurized and transport
airflow is provided by the fan separator.  When not in use,
the commode is depressurized for solid waste drying and
deactivation.
 
     Solid Waste enters the commode through the seat opening
(4.0 inches), drawn in by air flowing through holes under
the seat.  Waste material is deposited on the porous bag
liner.  Air is drawn through the hydrophobic material to the
fan separator.  The hydrophobic liner material prevents free
liquid and bacteria from exiting the collector.
 
     The urinal, essentially a funnel attached to a hose,
provides the capacity to collect and transport liquid waste
to the waste water tank.  The fan separator provides
transport airflow for the liquid.  The urinal can
accommodate both male and female crewmembers by use of a
male or female attachable cap.
 
     The fan separators provide transport airflow through
the commode and urinal, and separate the waste liquid from
the airflow.  The liquid/air mixture from the urinal line
enters axially, and is carried into a rotating secondary
separator which throws the liquid to the outer walls of the
rotating fluid reservoir, into a stationary Pitot tube, and
finally to the waste water tank.  Air is drawn out of the
rotating chamber by a blower, which also draws air from the
commode.  This air passes through the odor/bacteria filter,
and reenters the Orbiter cabin.  The filter can be removed
for in-flight replacement.
 
     The WCS vacuum vent QD provides the capability for the
crewmember to dump waste water directly overboard through
the vacuum vent system, if the waste water tank were to
fail.  This is accomplished by utilizing a water transfer
hose which is connected to the waste water crosstie QD.
 
WCS RESTRAINT AND ADJUSTMENT FEATURES
 
     The WCS employs various restraints and adjustments to
enable the user to achieve the proper body positioning in a
zero gravity environment.
 
     Two foot restraints are provided.  One (the "toe bar")
is located at the commode base and is used for restraint for
standup urination.  This restraint consists of two flexible
cylindrical pads on a shaft that can be adjusted to various
heights by releasing two locking levers.  The crewmmember
restrains himself in the standing position by slipping his
feet under the "toe bar" restraint.
 
     The second foot restraint (footrest) allows the
crewmember's feet to be restrained while sitting.  The
restraint consists of an adjustable platform with detachable
Velcro straps for securing the crewmember's feet.  The
Velcro straps are wrapped crosswire over each foot and
secured around the back.  The footrest can be adjusted to
various angles and heights.
 
     Two body restraints are provided.  The primary
restraint is the padded thigh bar.  The crewmember's sitting
position is secured by lifting up each thigh bar out of its
detent position, rotating over thigh, and releasing.  Bar is
preloaded to exert approximately 10 pounds of force on each
thigh.
 
     The second restraint serves as a backup method.  The
system consists of four Velcro thigh straps with a spring
hook on one end.  Two of the straps are attached to the top
front surface mating attached points.  The remaining two are
installed on a bracket with five holes on the upper sides of
the commode.  These straps can be positioned accordingly to
provide the proper restraint.
 
     Two handholds are used for positioning or stabilizing
the user during WCS operation.  They form an integral part
of the top cover of the WCS assembly.
 
WCS IN-FLIGHT CLEANING/MAINTENANCE
 
     WCS cleaning is scheduled as a daily in-flight
activity.  Biocidal cleanser, disposable gloves, general
purpose dry wipes, small wet wipes, and a Contingency
Scraper Tool (CST) are provided for cleaning the WCS.  A
urinal screen located at the base of the urinal funnel
captures air entrained debris and is replaced at least twice
daily.  The odor/bacteria filter is removed and replaced
with a spare filter when excessive odors are present.  In
addition, the personal hygiene station water hose is used at
least once per day to clean or flush areas of the urinal
with water.
 
POWER FOR WCS
 
     The WCS receives 115V ac and 28V dc power from two
middeck circuit breaker panels.  The fan separator motors
use ac power.  In addition, the switches to the fan
separators require dc power for operation.  There are six ac
breakers and two dc breakers.
 





For a more detailed description of the Shuttle toilet, see
Main Menu option 6, submenu 2, submenu 3, submenu 13, submenu 8,
submenu 8.

