A porterhouse.

For pressure-control purposes. A negative relief valve automatically dumps the excess water overboard. WASTE COLLECTOR ODOR/ SEAT BACTERIA FILTER WAIST COMMODE RESTRAINT OPERATING = HANDLE URINAL CONTROL HANDHOLD PANEL FAN SEPARATOR FOOT SELECTOR RESTRAINT SWITCH VACUUM SHUTOFF CONTROL ORBITER MID DECK MISSION STATION ONORBIT PIL er ONORBIT PAYLOAD .