The Lithium Hydroxide Management Plan for Removing Carbon Dioxide from the Space Shuttle while Docked to the International Space Station

The Lithium Hydroxide (LiOH) management plan to control carbon dioxide (CO₂) for the Shuttle while docked to the International Space Station (ISS) reduces the mass and volume needed to be launched. For missions before Flight UF-1/STS-108, the Shuttle and ISS each removed their own CO₂ during the docked time period. To control the CO₂ level, the Shuttle used LiOH canisters and the ISS used the Vozdukh or the Carbon Dioxide Removal Assembly (CDRA) with the Vozdukh being the primary ISS device for CO₂ removal. Analysis predicted that both the Shuttle and Station atmospheres could be controlled using the Station resources with only the Vozdukh and the CDRA. If the LiOH canisters were not needed for the CO₂ control on the Shuttle during the docked periods, then the mass and volume from these LiOH canisters normally launched on the Shuttle could be replaced with other cargo. On the Flight UF-1/STS-108 mission, a Station Detailed Test Objective (SDTO) showed the feasibility that both the Shuttle and Station atmospheres could be controlled using the Station resources.

This paper will discuss the methods and their priority for removing CO₂, how CDRA operations affect the plan, the sources of the LiOH canisters, the results of the SDTO, the performance and lifetime of the LiOH canisters, rotations plans, stowage issues, and future plans.