There is an assortment of hardware designed to work together to provide fluid servicing, seal leak checking and other plumbing-type services on the International Space Station (ISS). The Fluid Systems Servicer (FSS) is designed to drain, purge, fill, and recirculate fluids for on-orbit start-up, scheduled and unscheduled maintenance. The FSS will utilize space vacuum for purging operations on-orbit via the Vacuum Access Jumpers (VAJ), thus providing vacuum back-filling and static leak check capability with minimal power consumption. The FSS services Internal Thermal Control Systems (ITCS) and Environmental Control & Life Support (ECLS) System hardware in the pressurized elements of the ISS. The FSS gas/liquid separator fulfills an additional design requirement of removing entrained gas from fluids by means of a static membrane separator. The FSS and some ancillary equipment also perform Seal Leak Check (SLC), pressure removal and equalization, and window assembly maintenance on ISS. Two Desiccator/Filter Assemblies (DFA) are provided to perform window servicing requirements.
Several flex-line jumpers, adapters and Contingency Water Collection (CWC) bags, which interface various ISS and STS fluid line connectors via self-sealing Quick Disconnects (QD), are part of the VAJ, FSS, SLC Kit. There is also a NASA supplied Internal Sampling Adapter (ISA) which not only can sample atmosphere of adjacent elements, it provides accurate pressure reading on its Fluke digital pressure gage. The Integrated Hose Assemblies (IHA), CWCs and the DFA ORUs will be stowed on-orbit in the FSS rack in uniquely-shaped rack close-out “softpack” bags. Two softpack bags and the two large FSS Orbital Replacement Units (ORU), the Fluid Control and Pump Assembly (FCPA) and the FSS Supply Tank (ST), have permanent on-orbit rack stowage locations in the upper half of an Avionics system rack. The long FSS/IHA jumpers and VAJs can also be coiled into the empty volume in the cylindrical ends of the large FSS ORUs. The co-location of all the fluid servicing, seal leak check, and vacuum access equipment facilitates plumbing maintenance on the ISS.