The Waste Collector Subsystem is divided into three main subsystems: the urinal subassembly, the solid waste subassembly, and the vacuum subassembly.

 

URINAL SUBASSEMBLY- The purpose of the urinal subassembly is to collect urine in a zero gravity environment for males and females. The urinal is made up of the following elements:

    The urinal is in use when a crew member detaches the urinal pre-filter housing/hose assembly from the storage yoke. The crew member will then insert his or her own urine collection funnel to the pre-filter housing. The funnel is accommodated for “sit down” and “stand up” urination. When the urinal pre-filter hosing is removed, it turns one of the two phase fan separators on automatically. The fan separator provides air entrainment of the urine to the waste condensate tank located on the shuttle. The downstream urine-outlet check valve provides backflow protection and reduces air carryover in the urine outlet. Before the air returns to the cabin, it must go through the odor/bacteria filter, which provides filtration for the air. When the crew member is done urinating, he or she must remove their funnel from the hose pre-filter housing and place the pre-filter housing into the yoke.

 

SOLID WASTE SUBASSEMBLY- The solid waste subassembly is responsible for the compaction, collection, and storage of solid wastes. Listed below are the major components of the solid waste subassembly:

    The operation of the solid waste subassembly is basic and is divided into four parts: the “dormant” mode, the “use” mode, the “flush” mode, and the “service” mode.
    The “dormant” mode is when the commode is not in use or in a stand-by mode. The commode is always ready for use. The previous user must place a clean fecal bag in the top of the transport tube when he or she s done getting rid of his or her waste. The seat and cover assembly is closed in its position over the bag and transport tube to keep any unfiltered odors from becoming released into the cabin. If there is compacted waste at the bottom of the canister, odors and gasses travel out the plenum holes, through the plenum debris filter and through the redundant shut off centrifugal commode fans and into the odor/bacteria filter before exiting into the cabin.
    The “use” mode is when a crew member is using the commode to get rid of any body wastes. When a crew member has to use the commode, he or she unlatches the seat cover and moves the cover back away from the seat. When the crew member unlatches the seat cover, it automatically turns the commode fan on. The fan provides an air flow through the seat opening.
    The “flush” mode’s purpose is to contain and compact the waste into a canister located at the bottom of the transport tube. Placing a lid over the bag opening manually, accomplishes this action. The compactor is then put into place over the bag, and the compaction is started. The bag is then sealed and pushed into the canister. A new fecal bag is put into the transport tube just under the seat and the commode is put back into the “dormant” mode and ready for the next user.
    The forth mode is the “service” mode. This replaces the canister every week, or as needed. It also takes care of any sanitization depending on the size and usage of the crew. There is a light on the commode that indicates when approximately seven uses are left.

 

THE VACUUM VENT SUBSYSTEM- The vacuum vent subsystem is not only used for the toilet, it is also used for experiments conducted on the shuttle and for trash management.