International Space Station Water Use for Oxygen Generation

The International Space Station (ISS) recycles water. The environmental control and life support system is not currently a closed loop system. Oxygen must be resupplied on-orbit. ISS has Airlock tank oxygen, a Russian oxygen generator-Elektron, and Progress vehicle tank oxygen. The oxygen generator converts water into oxygen. About half of the resupplied water aboard ISS is used for oxygen generation. Past water usage predictions have not reflected times when the oxygen generator is on versus off. This can lead to over-predicting water resupply.

The water usage analysis calculates water usage from Progress vehicle resupply and oxygen generation from January 2003 to March 2004. The analysis shows the impacts of filling the Progress vehicles with oxygen. The analysis will determine the correlation between the Elektron water usage by the manual calculation method versus using Elektron current telemetry method.

Quantifying the impacts of Progress water resupply and finding the best tracking method will help make water resupply predictions more accurate in the future.