Overview of Long-Term Lithium Hydroxide Storage aboard the International Space Station

Lithium Hydroxide (LiOH) canisters have long been a staple of CO₂ scrubbing in manned space vehicles. LiOH is currently used as the exclusive scrubbing method for Space Shuttle (STS) operations and as a contingency aboard the International Space Station (ISS). Even considering recent developments in alternate regenerative CO2 scrubbing, LiOH is likely to be a part of manned spaceflight for the foreseeable future; and as such developing an improved understanding of long-term LiOH storage in a microgravity environment is beneficial. The contingency stockpile of LiOH aboard ISS provides a unique opportunity to observe the effects of long-term LiOH storage aboard a space vehicle. This paper will describe observations made in long-term LiOH stowage by both the crew and engineering teams working with the International Space Station and Space Shuttle programs; and discuss both possible explanations for observed conditions and possible improvements to be made.