PROJECT: Feasibility Study: Non-Hydraulic Cementitious Composite for Lunar Construction with In-situ Resources
PI: Nima Farzadnia, Assistant Professor, UAF
Lunar construction is a pivotal aspect of NASA’s space habitat programs, geared towards establishing the infrastructure necessary for a sustained human presence on the Moon. This infrastructure is vital for advancing deep space exploration, supporting scientific research, and potentially enabling human settlement beyond Earth. Nevertheless, the challenges of transporting construction materials to the Moon pose significant hurdles to lunar construction. Thus, there is a pressing need for lunar in-situ resource utilization to promote sustainable and cost-effective construction.
This project aims to investigate the feasibility of developing a non-hydraulic (zero water) cementitious composite using regolith for lunar construction. We will leverage alkali-activation technology, proven effective with a wide range of terrestrial aluminosilicates, alongside thermal processes. Solid molten alkali salts such as NaCO3, KCO3 will be used instead of conventional water-based activating solutions like sodium silicate/sodium hydroxide, thereby eliminating the need for water in the production process. Additionally, the project utilizes regolith derivatives, such as MgO and CaO, as additives to enhance the composite’s structural strength.
The hypothesis to be investigated is that the thermal activation, combined with the use of molten alkali salts, provides the necessary dissolving energy to break down the regolith structure without the need for water. This process results in development of a uniform molecular structure upon the polymerization of the dissolved species in regolith, such as SiO2, Al2O3, and CaO, to form a non-hydraulic composite for lunar construction. Design parameters, including the molten salt chemistry, molten salt-to-regolith ratio, and activating temperature and duration, will be investigated. The mixtures will be exposed to vacuum conditions to simulate the lunar construction environment. Comprehensive microstructural and mechanical analyses will be employed to investigate the feasibility of the investigated approach and refine the mixture design and synthesis process.
The findings of this project will provide insights into developing lunar construction materials that can withstand the harsh lunar environment, while also being suitable for use in robotic construction and additive manufacturing. We aim to maximize in-situ resource utilization, thereby reducing dependence on terrestrial materials and offering a sustainable, cost-effective solution for lunar construction and development programs, such as NASA’s Artemis Program.
The samples, ingredients, and pieces of lunar-style concrete.
Dane Woolery, undergraduate research assistant, prepping samples.
PROJECT: Identifying Snowlines on Glaciers Using Dual-Polarized Synthetic Aperture Radar
PI: Andrew Johnson, Postdoctoral Fellow, UAF
Alaskan glaciers are shrinking and losing mass, and snow plays an important role in the mass balance of glaciers. The snowline on a glacier at the end of a melt season helps to estimate the elevation below which the loss of mass by melt outweighs the gain of mass through snowfall. Optical satellite images of glaciers can differentiate snow, bare ice, and debris, but these platforms have difficulty monitoring snowlines over a melt season at regular intervals due the limitations imposed by cloud cover. This proposal will solve that problem by developing and evaluating methods to identify snow lines on glaciers using polarimetric Synthetic Aperture Radar (SAR) images. These methods are based on the principle that wet snow, dry snow, and bare ice cause different types of radar scattering, and the relative strength of different scattering types can be estimated from polarimetric SAR data.
In this work we will build a validation dataset of snow lines on glaciers from summer optical images using Sentinel-2 and Landsat. These images will be taken from around two sites, Mt. Wrangell and around Denali. Only cloud-free optical images where snow lines can be easily delineated will be used. Then we will obtain dual-polarized Sentinel-1 SAR images concurrent to within 48 hours of the optical images. We will perform two different polarimetric decompositions on these SAR images, one using the Single Look Complex (SLC) images, and one using a Radiometrically Terrain Corrected (RTC) product. We will evaluate the accuracy of snow identification from these SAR images relative to the optical image
dataset. After demonstrating that this methodology can accurately identify snow, we will apply it to identify snowlines across the glaciers in these areas of interest for the entire Sentinel-1 record of 2016 to present, and evaluate their evolution over time.
PROJECT: Droneborne Maritime Lidar Prototype Development
PI: Mike Roddewig, Assistant Professor, UAF
We are developing a prototype maritime lidar system for operation on a fixed-wing drone. Maritime lidar is a specialized type of lidar designed to penetrate natural water bodies such as the ocean, lakes, and rivers. It measures profiles of the water similar to an ultrasound scanning the human body. This type of lidar has numerous applications. It can be used to count fish, locate plankton, and measure the clarity and other properties of the water. This project will develop a prototype using the key components for a future droneborne lidar.
We propose to develop a breadboard prototype system of a droneborne maritime lidar, using the key components for the future droneborne system. Maritime lidar has a long heritage of airborne use, but no droneborne systems exist currently. Moving to a droneborne platform will reduce the cost of field experiments and enable new studies. To enable droneborne operation, we will need to reduce the size, weight, power, and cost (SWaP-C) of previous airborne platforms. Such a reduction has been recently enabled through micropulse lasers and system-on-chip (SoC) miniaturization where the analog-to-digital converter (ADC), field-programmable gate array (FPGA), and microcontroller are packaged into one integrated circuit.
Maritime lidars have numerous remote sensing applications, ranging from monitoring of fisheries, profiling of chlorophyll, phytoplankton, and zooplankton, study of internal layers, and measurement of water optical properties. However, maritime lidars that fly on manned aircraft are large and require high-power lasers (with their commensurate eye safety concerns and power draw), expensive detectors, and large receiver telescopes to compensate for the higher minimum safe altitude for a manned aircraft.
In contrast, our proposed droneborne system uses a small, comparatively inexpensive, and safer micropulse laser, a widely available and inexpensive avalanche photodiode (APD) detector, 2.5 cm diameter telescope optics, and is designed to be flown on a fixed-wing drone. The droneborne lidar has the same performance as its airborne counterparts due to the much lower altitude that a drone can safely fly versus a manned aircraft (10 m vs. 300 m), which dramatically reduces the laser power and receiver sensitivity required to achieve a reasonable penetration depth.
A custom, micropulse 532 nm laser developed in collaboration with Quantum Composers (Bozeman, Montana)
PROJECT: Development of Advanced Optical CO2 Sensor for Space Habitation
PI: Lei Zhang, Professor, UAF
Monitoring CO2 levels in space habitation is crucial in ensuring astronauts stay healthy, safe, and continue optimal performance. Two primary systems have been used to monitor CO2 in the U.S. modules on the International Space Station (ISS): the service module gas analyzer and the major constituent analyzer. Both systems are limited by their fixed sampling locations. The lack of air convection in microgravity makes ventilation and accurate monitoring difficult as the recorded value at fixed sampling
sites may not reflect the environment immediately surrounding the crew. In addition to these systems, non-dispersive infrared spectroscopy is considered a low-cost, sensitive detection technique for detecting CO2 during manned space flight. However, measurements are not reliable and error rate increases with variation of pressure and composition of gas. A more flexible and accurate sensor system is required for reliable measurement and monitoring of CO2. This project aims to develop a cost-effective, more convenient, and long-lasting CO2 colorimetric optical sensor as a potential robust and real-time air-quality monitoring system for accurate, reliable, and sensitive detection of CO2.
The goal of this project is to develop a cost-effective, more convenient, and long-lasting water-based CO2 colorimetric optical sensor (WCCOS) with improved sensitivity by incorporating albumin in the WCCOS design. There are three objectives in this project: (1) fabricate a water-based CO2 colorimetric optical sensor containing albumin, (2) examine the effect of albumin on the sensitivity of CO2 colorimetric optical sensor, and (3) examine the effect of albumin on the lifetime of the new CO2 colorimetric optical sensor design. It is noted that this seed grant is intended to support prototype development of structural modifications to the sensor coating for sensitivity improvement.
Schematic representation of a mechanism of facilitated CO2 diffusion across a layer of albumin solution which is exposed to a PCO2 gradient: CO2 is transported through the layer by diffusion of HCO3– and simultaneous albumin-facilitated H+ diffusion.