Future space exploration missions present significant new challenges to crew health care capabilities, particularly in the efficient utilization of on-board oxygen resources. The International Space Station and future exploration vehicles require a light weight, compact, portable oxygen concentrator technology (OCT) that can provide medical grade oxygen from the ambient cabin air. Current OCTs are heavy, bulky, have a narrow operating temperature range (ambient to 40 degree Celsius), and require 15 to 30 minutes start-up time to reach their full operating capacity. Lynntech's proposed electrochemical OCT solves these issues by operating the OCT with a cathode-air vapor feed, unlike conventional electrochemical OCTs which require a liquid water feed. This is possible due to the use of in-house developed proprietary nanocomposite proton exchange membrane and catalyst technologies. Cathode-air vapor feed operation eliminates the need for a bulky on-board water supply, significantly reduces the complexity of the balance-of-plant, and greatly increases the system efficiency. OCT will be a quarter the size and weight of conventional OCTs, be capable of instant start-up, and have a wide operating temperature range. Lynntech will develop a Phase II prototype that is capable of delivering 4 SLPM of 60% oxygen and deliver it to NASA for further testing.