Development Status of the ISS Oxygen Generation Assembly and Key Components

Hamilton Sundstrand Space Systems International, Inc. (HSSSI) is under contract to NASA Marshall Space Flight Center (MSFC) to develop, an Oxygen Generation Assembly (OGA) for the International Space Station (ISS). The Oxygen Generation Assembly (OGA) electrolyzes potable water from the Water Recovery System (WRS) to provide gaseous oxygen to the Space Station module atmosphere. The OGA produces oxygen for metabolic consumption by crew and biological specimens. The OGA also replenishes oxygen lost by experiment ingestion, airlock depressurization, CO2 venting, and leakage. As a byproduct, gaseous hydrogen is generated. The hydrogen will be supplied at a specified pressure range to support future utilization. Initially, the hydrogen will be vented overboard to space vacuum.

The OGA has been under development at HSSSI for 3 years. This paper will update last year's ICES paper on the design/development of the OGA. It will also present a key technology, the two-phase fluid sensor (bubble detector), which is being developed for the OGA to provide a failure detection capability. The bubble detector is an optical sensor which monitors the cross-section of a flow stream and generates a signal indicating the presence of free gas in the feed water.