Search

Given the significant impact of fO2 on material properties, it is important to perform studies at fO2 values relevant to the sample of interest. However, current systems used to control fO2 in solid media assemblies (e.g., sliding sensors, graphite capsule buffering) have limited ability to produce the wide fO2 ranges necessary to simulate more extreme planetary interiors. NASA's fO2 control system implements a modified double capsule design that utilizes a wide range of solid metal-oxide buffers to control fO2 across a wide range of conditions. The approach is a modification of the previous double capsule design wherein the outer capsule itself acts as the metal component of the buffer assemblage, and the inner capsule to which the astromaterial sample of interest is placed resides within the outer capsule. To achieve higher experimental temperatures above the melting point of more traditional noble metal capsule materials, outer capsules of the control assembly are comprised of refractory (high melting point) metals such as Ni, Co, W, Fe, Mo, V, Cr, Nb and Ta. Resultant experiments have reliably achieved temperatures exceeding 1600 degrees C, and when used in conjunction with a multi-anvil press, system pressures of over 20 GPa can be obtained lending researchers the ability to simulate on or off-world geologic conditions previously difficult to obtain in a laboratory. NASA's fO2 control system was developed to enable high pressure, high temperature experimental studies of astromaterials at fO2 values relevant to the sample of interest. However, it may also be useful for the synthesis of materials where fO2 control is required (e.g., synthesis of crystal structures that might be stable under higher oxygen pressure). Further use cases may include mineral or melt syntheses, metal-silicate or mineral-melt element partitioning, phase equilibria studies, and the possible development of new chemical and mineral compounds that could not be manufactured in laboratories before. This fO2 control system technology is at a technology readiness level (TRL) 6 (system/subsystem prototype demonstration in a relevant environment). The innovation is now available for your company to license. Please note that NASA does not manufacture products itself for commercial sale.

NASA Ames has developed very small-sized oxygen sensors made of a graphene and titanium dioxide (TiO₂) hybrid material. With ultraviolet (UV) illumination, these sensors are capable of detecting oxygen (O₂) gas at room temperature and at ambient pressure. The sensors are able to detect oxygen at concentrations ranging from about 0.2% to about 10% by volume under 365nm UV light, and at concentrations ranging from 0.4% to 20% by volume under short wave 254nm UV light. These sensors have fast response and recovery times and can also be used to detect ozone. This unique room temperature O₂ sensor provides significant advantages in O₂ sensing applications, especially those applications where high operating temperature requirements cannot be met, or would result in inefficient manufacturing processes. Since graphene is not intrinsically responsive to O₂, and TiO₂ is not responsive to oxygen at room temperature, the materials are first synthesized as a hybrid material. The synthesized graphene- TiO₂ hybrid material is then ultrasonicated and then drop-casted onto a series of Interdigitated Electrodes (IDE) to form the sensors. Ultrasonication ensures effective charge transfer at the graphene- TiO₂ interphase. The graphene and the titanium dioxide may be present in the composite material in different ratios to ensure optimal oxygen detection. It is the combination of graphene with TiO2 that yields a semiconducting material capable of O₂ sensing at room-temperature operation.

The NASA life support system uses a regenerable vacuum swing adsorption process, known as Sorbent-Based Air Revitalization (SBAR), to separate water and carbon dioxide for disposal. The SBAR system is an adsorbent-based swing bed system that has been optimized to provide both humidity and carbon dioxide control for a spacecraft cabin atmosphere. The system comprises composite silica gel and zeolite-packed beds for adsorption and a bypass system for flow control. Under normal operating conditions, the disposal system would require a high-quality vacuum environment to operate. Improvements to the SBAR system include an enhanced inherent capacitance that extends the operation time within a non-vacuum environment for up to 4.5 hours. Flight time can be further expanded with multiple SBAR systems to allow for system regeneration. By scheduling periodic thermal regenerations&#151nominally during sleep periods&#151the SBAR technology may be suitable for missions of unlimited duration.

Storage and transfer of fluid commodities such as oxygen, hydrogen, natural gas, nitrogen, argon, etc. is an absolute necessity in virtually every industry on Earth. These fluids are typically contained in one of two ways; as low pressure, cryogenic liquids, or as a high pressure gases. Energy storage is not useful unless the energy can be practically obtained ("un-stored") as needed. Here the goal is to store as many fluid molecules as possible in the smallest, lightest weight volume possible; and to supply ("un-store") those molecules on demand as needed in the end-use application. The CFC concept addresses this dual storage/usage problem with an elegant charging/discharging design approach. The CFC's packaging is ingeniously designed, tightly packing aerogel composite materials within a container allows for a greater amount of storage media to be packed densely and strategically. An integrated conductive membrane also acts as a highly effective heat exchanger that easily distributes heat through the entire container to discharge the CFC quickly, it can also be interfaced to a cooling source for convenient system charging; this feature also allows the fluid to easily saturate the container for fast charging. Additionally, the unit can be charged either with cryogenic liquid or from an ambient temperature gas supply, depending on the desired manner of refrigeration. Finally, the heater integration system offers two promising methods, both of which have been fabricated and tested, to evenly distribute heat throughout the entire core, both axially and radially.