International Space Station module acceptance leak testing

The International Space Station (ISS) has a planned life of 10 years, and restrictions on resupply air make the Station's atmospheric leakage to space critical. The leak rate requirement on the entire ISS is two pounds of air per day, and this translates to approximately one tenth of a pound of air per day for each pressurized module. Leakage of the internal plumbing is also critical for crew safety and system performance considerations. An incremental acceptance testing approach was used to test the hardware as it was built up. Then system-level and module-level tests were performed to verify system leakage requirements. Innovative leak test methods and hardware were used in the performance of quantitative and efficient leak tests.