Low Impact Iterative Solutions to Fluid Quick Disconnect Integrated Testing Anomalies on the International Space Station 2002-01-2365
The International Space Station (ISS) has an extensive set of fluid lines that transport ammonia, nitrogen, and water, enabling thermal control of the space station. The fluid transportation system is primarily composed of welded stainless steel tubing. EVA serviceable connections are achieved using flexible hoses welded to pressure balanced Quick Disconnects (QDs). Because of ISS's unique requirements, all its designs are first time applications and were being simultaneously developed. Although most requirements were met by the hose developer, QD vendor, and the system assembly designer, the first high fidelity testing of the system did not occur until very late in the program. The ISS has over 200 fluid Quick Disconnect (QD) couplings that allow fluid lines to be connected and disconnected for assembly and maintenance tasks while maintaining pressures of up to 500 psi in the fluid system and preventing leakage. The fluid QD's work under high pressure and highly variable thermal conditions and are required to be operable by EVA astronauts wearing space suits. This paper discusses solutions that were developed for three problems that were discovered in testing and ground operations of fluid QD's: high forces required for mating and demating QD's, a potentially hazardous false mating condition, and damage to sealing surfaces in ground operations. Low impact solutions to these problems were developed, primarily incorporating changes in procedures and development of tools, with minimal changes to flight hardware designs.