Description: Studying the isotopic composition of materials is an established method to obtain detailed insight into formation and evolution processes in our Universe. Water may play a dominant role in unraveling these processes. Isotope hydrology applied in situ on the Moon and other planets might develop into the key method to understand the history of our Solar system. The Moon provides unique opportunities to study trapped volatile compounds, like water, due to the special conditions at its poles. These conditions enable the long term storage of volatiles and preservation of their isotopic composition. A compact, precise isotope hygrometer operated on the Moon will be an invaluable tool if abundant water sources are found on the Moon in upcoming missions. This project seeks to develop a highly sensitive, portable water isotope ratiometer for precisely measuring water samples in situ on the Moon. The optical sensors developed on this project will have unique features including fast response, high precision and strong species selectivity. Design criteria such as a small footprint, low weight, low power consumption and continuous sensor health monitoring will be implemented to optimize the sensors for application to the Moon. An absorption approach using modulation techniques will be implemented on a lunar mission suitable platform.

Benefits: This project will lead to a small portable sensor for use in isotope hydrology. Water isotope data provide information about past and present global climate and the global water cycle on Earth. They allow mapping of aquifers, conserving water supplies and trace transport and dispersion of contaminants in the subsurface. The fully-developed prototype instruments shall offer a compelling and desirable blend of compactness, performance, affordability, simplicity and ease-of-use relative to present commercial product offerings in these applications. Beyond these applications, the developed sensor platform will be broadly deployable for trace gas detection of a variety of molecules with a cost-effective, small device. Examples include contaminant monitoring in process gas streams in the chemical and microelectronics industries, medical diagnosis through detection of biogenic gases in human breath that correlate to specific pathologies, and environmental monitoring and regulatory compliance in agriculture, power production, and occupational safety. The targeted NASA applications are analyzing water samples on the Moon as well as on other planets. The emerging technology is adaptable to changing pressure conditions and suitable to operate in diverse environments, including corrosive atmospheres. The developed technology can be extended to selectively detect trace gas species for NASA relevant applications such as contaminant sensing in air revitalization and water recovery processes, and atmospheric composition monitoring.