Analysis of the Effect of Age on Shuttle Orbiter Lithium Hydroxide Canister Performance 2005-01-2768
Recent efforts have been pursued to establish the usefulness of Space Shuttle Orbiter lithium hydroxide (LiOH) canisters beyond their certified two-year shelf life, at which time they are currently considered “expired.” A stockpile of Orbiter LiOH canisters are stowed on the International Space Station (ISS) as a backup system for maintaining ISS carbon dioxide Canisters with older (CO2) control. Canister with older pack dates must routinely be replaced with newly packed canisters off-loaded from the Orbiter Middeck. Since conservation of upmass is critical for every mission, the minimization of canister swap-out rate is paramount.
LiOH samples from canisters with expired dates that had been returned from the ISS were tested for CO2 removal performance at the NASA Johnson Space Center (JSC) Crew and Thermal Systems Division (CTSD). Through this test series and subsequent analysis, performance degradation was established. There was insufficient sample size to define performance degradation as a function of time, but this will be the goal of follow-on studies as more data is accumulated. However, the analysis concluded that although the expired ISS LiOH could be expected to exhibit performance degradation, with proper LiOH change-out management it could be used in the Orbiter for the Return to Flight (RTF) mission (STS-114, ISS LF1) without exceeding CO2 limits.