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A Mars Micro-Meteorological Station Mission

The Mars Micro-Meteorological Station (Micro-Met) Mission is designed to provide the global surface pressure measurements required to help characterize the martian general circulation and climate system. Measurements of surface pressure distributed both spatially and temporally, coupled with simultaneous measurements from orbit, will enable the determination of the general circulation, structure and driving factors of the martian atmosphere as well as the seasonal CO2 cycle. The influence of these atmospheric factors will in turn provide insight into the overall martian climate system. With the science objective defined as the long term (at least one Mars year) globally distributed measurement of surface atmospheric pressure, a straightforward, near term and low cost network mission has been designed. The Micro-Met mission utilizes a unique silicon micro-machined pressure sensor coupled with a robust and lightweight surface station to deliver to Mars 16 Micro-Met stations via a Med-Lite launch vehicle. The battery powered Micro-Met surface stations are designed to autonomously measure, record and transmit the science data via a UHF relay satellite. Entry, descent and landing is provided by an aeroshell with a new lightweight ceramic thermal protection system, a parachute and an impact absorbing structure. The robust lander is capable of surviving the landing loads imposed by the high altitude landing sites required in a global network. By trading the ability to make many measurements at a single site for the ability to make a single measurement at several sites, the Micro-Met mission design satisfies the requirement for truly global meteorological science.

Merrihew, Steven C.

Source Term Model for Steady Micro Jets in a Navier-Stokes Computer Code

A source term model for steady micro jets was implemented into a non-proprietary Navier-Stokes computer code, OVERFLOW. The source term models the mass flow and momentum created by a steady blowing micro jet. The model is obtained by adding the momentum and mass flow created by the jet to the Navier-Stokes equations. The model was tested by comparing with data from numerical simulations of a single, steady micro jet on a flat plate in two and three dimensions. The source term model predicted the velocity distribution well compared to the two-dimensional plate using a steady mass flow boundary condition, which was used to simulate a steady micro jet. The model was also compared to two three-dimensional flat plate cases using a steady mass flow boundary condition to simulate a steady micro jet. The three-dimensional comparison included a case with a grid generated to capture the circular shape of the jet and a case without a grid generated for the micro jet. The case without the jet grid mimics the application of the source term. The source term model compared well with both of the three-dimensional cases. Comparisons of velocity distribution were made before and after the jet and Mach and vorticity contours were examined. The source term model allows a researcher to quickly investigate different locations of individual or several steady micro jets. The researcher is able to conduct a preliminary investigation with minimal grid generation and computational time.

Waithe, Kenrick A.

Active Fail-Safe Micro-Array Flow Control for Advanced Embedded Propulsion Systems

The primary objective of this research effort was to develop and analytically demonstrate enhanced first generation active "fail-safe" hybrid flow-control techniques to simultaneously manage the boundary layer on the vehicle fore-body and to control the secondary flow generated within modern serpentine or embedded inlet S-duct configurations. The enhanced first-generation technique focused on both micro-vanes and micro-ramps highly-integrated with micro -jets to provide nonlinear augmentation for the "strength' or effectiveness of highly-integrated flow control systems. The study focused on the micro -jet mass flow ratio (Wjet/Waip) range from 0.10 to 0.30 percent and jet total pressure ratios (Pjet/Po) from 1.0 to 3.0. The engine bleed airflow range under study represents about a 10 fold decrease in micro -jet airflow than previously required. Therefore, by pre-conditioning, or injecting a very small amount of high-pressure jet flow into the vortex generated by the micro-vane and/or micro-ramp, active flow control is achieved and substantial augmentation of the controlling flow is realized.

Anderson, Bernhard H.

Navigating Team Dynamics: Automated Detection of Micro-Behaviors Between Team Members Through Longitudinal Interaction Data

The success in future long term space exploration missions will depend on the cooperation, coordination, and mutual understanding among the crew members. Micro-behaviors are momentary, subtle linguistic and paralinguistic indicators of thinking and feeling toward another member of the team (Cortina et al., 2001; Smith & Griffiths, 2022) that can significantly impact team dynamics and influence the overall team performance (Paromita & Chaspari, 2024). Due to their interactive nature, micro-behaviors have a sender (i.e., the team member expressing the micro-behavior) and a target (the team member impacted by the micro-behavior). Detection of these behaviors can assist in avoiding possible conflict among crew members and promoting the overall team success. Our prior research focused on an initial proof of concept of machine learning (ML) models and natural language processing (NLP) techniques that were used for automatically detect micro-behaviors among crew members of the US National Aeronautics and Space Administration’s (NASA) Human Exploration Research Analog (HERA) Campaigns 4 and 5 missions (Paromita et al., 2023). Results underscored the importance of incorporating contextual information in the ML models in the form of sentiment analysis, type of task, and dyadic interaction among team members. Here, we expand the scope of our prior work in two ways. First, we assess ML/NLP methods on new behavioral annotations coded using an adapted version of Smith & Griffins (2022) theoretical framework in terms of Violation (i.e., presence of valenced behavior, uplifting/positive or discouraging/negative), Intensity (i.e., force of behavior in terms of how uplifting or discouraging is the behavior), and Intent (i.e., motive of the behavior in terms of whether it was deliberate or unintentional). Second, we expand the design of the ML model to preserve information about the role of each team member within the occurrence of the micro-behavior (in contrast to the previous model that only considered the sender and the target without determining the team member role). This allows to consider all team members' contributions in the conversation and model long-term dependencies in the dialogue. Our experiments for this study are conducted on data from 5 teams of the NASA HERA C4 (NASA grant NNX16AQ48G (PI: Bell)). Conversations were extracted from the 1.5 hour Team Interaction Battery (TIB) task that occurred 5 times in-mission per crew. This resulted in a total of 13,058 conversational turns (i.e., 17.8% uplifting, 3.3% discouraging, 75.76% neutral, 3.14% nulls). Our findings with the revised behavioral coding and ML/NLP models indicate a 43.66% macro F1-score (i.e., 38.29% precision (P), 50.8% recall (R)) for a dialog state-tracking model that includes information from the sender only, and a 40.9% F1-score (i.e., 38.7% P, 43.36% R) for the same model that includes information from both the sender and the target of the micro-behavior. These are significantly higher compared to simple random forest models that classify behaviors strictly based on speech content and do not consider iterative team dynamics, achieving a 36.07% F1-score (i.e., 39.04% R, 33.53% P). Our findings demonstrate potential ways to leverage large conversational datasets to better capture complex team dynamics. We will discuss future directions including proposed models that can incorporate additional mission days and tasks beyond the TIB for objectively quantifying team behavior at high temporal resolution in space exploration missions.

Projna Paromita

Residential Home Decarbonization Using Advanced Micro-CHP

An efficient micro-combined heat and power (CHP) prototype was developed to provide heat and electricity for single-family homes and light commercial buildings. The unit can be installed independently at the point of energy consumption. Consequently, it enables cost-effectively and flexibly matching heat and electrical loads, simplifying distribution and installation processes, and recovering and storing waste heat as hot water. The analyzed results show that the micro-CHP using natural gas as fuel achieves 10.68%–32.80% CO2 reduction in the selected five home applications. The potential effect of H2 on decarbonization of these home was also evaluated, finding that the micro-CHP using a blended fuel with H2 and natural gas can further reduce CO2 emissions. However, the 50% CO2 reduction in the micro-CHP requires at least 70%–90% of H2 in the blend with natural gas. Overall, the micro-CHP technology demonstrates a solid potential to accelerate micro-CHP adoption in residential and light commercial markets, thereby promoting broader micro-CHP acceptance and use in the future for building decarbonization.

Gao, Zhiming [ORNL] (ORCID:0000000271397995)

Low Cost Micro-Spectrometer for Resource Mapping on Mars

Scientific measurements within craters and along steep embankments on Mars pose extreme challenges since astronauts and rovers cannot access them. However, these areas offer the potential for thegreatest scientific return. NASA Langley Research Center (LaRC) has invented a deployable wireless micro-spectrometer [1-13] capable of accessing thosechallenging areas and, using telemetry, send measurements to a receiver safely outside those extreme environments. A prototype of the micro-spectrometer concept was fabricated and successfullytested for measurement of dopamine as a neural probe [14]. The bullet-sized micro-spectrometer concept can be designed for deployment by an astronaut, a rover, an aerial drone, or a lander, and the measurements broadcasted back to a receiver [13,15,16]. This device can also be installed on rovertires, under the astronaut’s boots, or a cane stick. The bullet-like consumable micro-spectrometer can penetrate soil to spectrally identify the components ofthe soil, such as water or minerals. The signals of the soil assay data are transmitted to a mother station through a telemetry system. The LaRC developed micro-spectrometer bullet consists of micro-spectrometer optics with an all imbedded burst-mode LED UV light source, a super-capacitor with control electronics, and telemetry electronics. Prototypes have been fabricated to demonstrate spectral assay of soil components. Further maturation of this technology would be necessary for demonstration on Mars. Future work includes a potential R&D program that includes other NASA Centers and industry partners interested in developing a business case that requires knowledge of the locations of extraterrestrial ice, for instance.

micro-spectrometer, mineral assay, resource mappin

The growth and harvesting of algae in a micro-gravity environment

Algae growth in a micro-gravity environment is an important factor in supporting man's permanent presence in space. Algae can be used to produce food, oxygen, and pure water in a manned space station. A space station is one example of a situation where a Controlled Ecological Life Support System (CELSS) is imperative. In setting up a CELSS with an engineering approach at the Aerospace department of the University of Colorado, questions concerning algae growth in micro-g have arisen. The Get Away Special (GAS) Fluids Management project is a means through which many questions about the effects of a micro-g environment on the adequacy of growth rates, the viability of micro-organisms, and separation of gases and solids for harvesting purposes can be answered. In order to be compatible with the GAS tests, the algae must satisfy the following criteria: (1) rapid growth rates, (2) sustain viability over long periods of non-growth storage, and (3) very brief latency from storage to rapid growth. Testing indicates that the overall growth characteristics of Anacystis Nidulans satisfy the specifications of GAS's design constraints. In addition, data acquisition and the method of growth instigation are two specific problems being examined, as they will be encountered in interfacing with the GAS project. Flight testing will be two-fold, measurement of algae growth in micro-g and separation of algae from growth medium in an artificial gravitation field. Post flight results will provide information on algae viability in a micro-g environment as reflected by algal growth rates in space. Other post flight results will provide a basis for evaluating techniques for harvesting algae. The results from the GAS project will greatly assist the continuing effort of developing the CELSS and its applications for space.

Wiltberger, Nancy L.

Micro guidance and control technology overview

This paper gives an overview of micro-guidance and control technologies and in the process previews of the technology/user and systems issues presented in the guidance and control session at the workshop. We first present a discussion of the advantages of using micro-guidance and control components and then detail six micro-guidance and control thrusts that could have a revolutionary impact on space missions and systems. Specific technologies emerging in the micro-guidance and control field will be examined. These technologies fall into two broad categories: micro-attitude determination (inertial and celestial) and micro-actuation, control and sensing. Finally, the scope of the workshop's guidance and control panel are presented.

Kissel, Glen J.

The micro conical system: Lessons learned from a successful EVA/robot-compatible mechanism

The Micro Conical System (MCS) is a three-part, multi-purpose mechanical interface system used for acquiring and manipulating masses on-orbit by either extravehicular activity (EVA) or telerobotic means. The three components of the system are the micro conical fitting (MCF), the EVA micro tool (EMCT), and the Robot Micro Conical Tool (RMCT). The MCS was developed and refined over a four-year period. This period culminated with the delivery of 358 Class 1 and Class 2 micro conical fittings for the International Space Station and with its first use in space to handle a 1272 kg (2800 lbm) Spartan satellite (11000 times greater than the MCF mass) during an EVA aboard STS-63 in February, 1995. The micro conical system is the first successful EVA/robot-compatible mechanism to be demonstrated in the external environment aboard the U.S. Space Shuttle.

Gittleman, Mark

Micro Navigator

Miniature high-performance low-mass space avionics systems are desired for planned future outer planetary exploration missions (i.e. Europa Orbiter/Lander, Pluto-Kuiper Express). The spacecraft fuel and mass requirements enabling orbit insertion is the driving requirement. The Micro Navigator is an integrated autonomous Guidance, Navigation & Control (GN&C)micro-system that would provide the critical avionics function for navigation, pointing, and precision landing. The Micro Navigator hardware and software allow fusion of data from multiple sensors to provide a single integrated vehicle state vector necessary for six degrees of freedom GN&C. The benefits of this MicroNavigator include: 1) The Micro Navigator employs MEMS devices that promise orders of magnitude reductions in mass power and volume of inertial sensors (accelerometers and gyroscopes), celestial sensing devices (startracker, sun sensor), and computing element; 2) The highly integrated nature of the unit will reduce the cost of flight missions. a) The advanced miniaturization technologies employed by the Micro Navigator lend themselves to mass production, and therefore will reduce production cost of spacecraft. b) The integral approach simplifies interface issues associated with discrete components and reduces cost associated with integration and test of multiple components; and 3) The integration of sensors and processing elements into a single unit will allow the Micro Navigator to encapsulate attitude information and determination functions into a single object. This is particularly beneficial for object-oriented software architectures that are used in advanced spacecraft. Additional information is contained in the original extended abstract.

Blaes, B. R.

Optimal Micro-Vane Flow Control for Compact Air Vehicle Inlets

The purpose of this study on micro-vane secondary flow control is to demonstrate the viability and economy of Response Surface Methodology (RSM) to optimally design micro-vane secondary flow control arrays, and to establish that the aeromechanical effects of engine face distortion can also be included in the design and optimization process. These statistical design concepts were used to investigate the design characteristics of "low unit strength" micro-effector arrays. "Low unit strength" micro-effectors are micro-vanes set at very low angles-of-incidence with very long chord lengths. They were designed to influence the near wall inlet flow over an extended streamwise distance, and their advantage lies in low total pressure loss and high effectiveness in managing engine face distortion. Therefore, this report examines optimal micro-vane secondary flow control array designs for compact inlets through a Response Surface Methodology.

Anderson, Bernhard H.

Micro-Vibration Measurements on Thermally Loaded Multi-Layer Insulation Samples in Vacuum

Some scientific missions require to an extreme extent the absence of any on-board microvibration. Recent projects dedicated to measuring the Earth's gravity field and modeling the geoid with extremely high accuracy are examples. Their missions demand for extremely low micro-vibration environment on orbit for: (1) Not disturbing the measurement of earth gravity effects with the installed gradiometer or (2) Even not damaging the very high sensitive instruments. Based on evidence from ongoing missions multi-layer insulation (MLI) type thermal control blankets have been identified as a structural element of spacecrafts which might deform under temperature variations being caused by varying solar irradiation in orbit. Any such deformation exerts tiny forces which may cause small reactions resulting in micro-vibrations, in particular by exciting the spacecraft eigenmodes. The principle of the test set-up for the micro-vibration test was as follows. A real side wall panel of the spacecraft (size about 0.25 m2) was low-frequency suspended in a thermal vacuum chamber. On the one side of this panel, the MLI samples were fixed by using the standard methods. In front of the MLI, an IR-rig was installed which provided actively controlled IR-radiation power of about 6 kW/m2 in order to heat the MLI surface. The cooling was passive using the shroud temperature at a chamber pressure <1E-5mbar. The resulting micro-vibrations due to MLI motion in the heating and the cooling phase were measured via seismic accelerometers which were rigidly mounted to the panel. Video recording was used to correlate micro-vibration events to any visual MLI motion. Different MLI sample types were subjected to various thermal cycles in a temperature range between -60 C to +80 C. In this paper, the experience on these micro-vibration measurements will be presented and the conclusions for future applications will be discussed

Deutsch, Georg

Micro-Inspector Spacecraft for Space Exploration Missions

NASA is seeking to embark on a new set of human and robotic exploration missions back to the Moon, to Mars, and destinations beyond. Key strategic technical challenges will need to be addressed to realize this new vision for space exploration, including improvements in safety and reliability to improve robustness of space operations. Under sponsorship by NASA's Exploration Systems Mission, the Jet Propulsion Laboratory (JPL), together with its partners in government (NASA Johnson Space Center) and industry (Boeing, Vacco Industries, Ashwin-Ushas Inc.) is developing an ultra-low mass (<3.0 kg) free-flying micro-inspector spacecraft in an effort to enhance safety and reduce risk in future human and exploration missions. The micro-inspector will provide remote vehicle inspections to ensure safety and reliability, or to provide monitoring of in-space assembly. The micro-inspector spacecraft represents an inherently modular system addition that can improve safety and support multiple host vehicles in multiple applications. On human missions, it may help extend the reach of human explorers, decreasing human EVA time to reduce mission cost and risk. The micro-inspector development is the continuation of an effort begun under NASA's Office of Aerospace Technology Enabling Concepts and Technology (ECT) program. The micro-inspector uses miniaturized celestial sensors; relies on a combination of solar power and batteries (allowing for unlimited operation in the sun and up to 4 hours in the shade); utilizes a low-pressure, low-leakage liquid butane propellant system for added safety; and includes multi-functional structure for high system-level integration and miniaturization. Versions of this system to be designed and developed under the H&RT program will include additional capabilities for on-board, vision-based navigation, spacecraft inspection, and collision avoidance, and will be demonstrated in a ground-based, space-related environment. These features make the micro-inspector design unique in its ability to serve crewed as well as robotic spacecraft, well beyond Earth-orbit and into arenas such as robotic missions, where human teleoperation capability is not locally available.

microspacecraft

Micro-Tubular Fuel Cells

Micro-tubular fuel cells that would operate at power levels on the order of hundreds of watts or less are under development as alternatives to batteries in numerous products - portable power tools, cellular telephones, laptop computers, portable television receivers, and small robotic vehicles, to name a few examples. Micro-tubular fuel cells exploit advances in the art of proton-exchange-membrane fuel cells. The main advantage of the micro-tubular fuel cells over the plate-and-frame fuel cells would be higher power densities: Whereas the mass and volume power densities of low-pressure hydrogen-and-oxygen-fuel plate-and-frame fuel cells designed to operate in the targeted power range are typically less than 0.1 W/g and 0.1 kW/L, micro-tubular fuel cells are expected to reach power densities much greater than 1 W/g and 1 kW/L. Because of their higher power densities, micro-tubular fuel cells would be better for powering portable equipment, and would be better suited to applications in which there are requirements for modularity to simplify maintenance or to facilitate scaling to higher power levels. The development of PEMFCs has conventionally focused on producing large stacks of cells that operate at typical power levels >5 kW. The usual approach taken to developing lower-power PEMFCs for applications like those listed above has been to simply shrink the basic plate-and-frame configuration to smaller dimensions. A conventional plate-and-frame fuel cell contains a membrane/electrode assembly in the form of a flat membrane with electrodes of the same active area bonded to both faces. In order to provide reactants to both electrodes, bipolar plates that contain flow passages are placed on both electrodes. The mass and volume overhead of the bipolar plates amounts to about 75 percent of the total mass and volume of a fuel-cell stack. Removing these bipolar plates in the micro-tubular fuel cell significantly increases the power density.

Kimble, Michael C.

X-ray Micro-Tomography of Ablative Heat Shield Materials

X-ray micro-tomography is a non-destructive characterization technique that allows imaging of materials structures with voxel sizes in the micrometer range. This level of resolution makes the technique very attractive for imaging porous ablators used in hypersonic entry systems. Besides providing a high fidelity description of the material architecture, micro-tomography enables computations of bulk material properties and simulations of micro-scale phenomena. This presentation provides an overview of a collaborative effort between NASA Ames Research Center and Lawrence Berkeley National Laboratory, aimed at developing micro-tomography experiments and simulations for porous ablative materials. Measurements are carried using x-rays from the Advanced Light Source at Berkeley Lab on different classes of ablative materials used in NASA entry systems. Challenges, strengths and limitations of the technique for imaging materials such as lightweight carbon-phenolic systems and woven textiles are discussed. Computational tools developed to perform numerical simulations based on micro-tomography are described. These enable computations of material properties such as permeability, thermal and radiative conductivity, tortuosity and other parameters that are used in ablator response models. Finally, we present the design of environmental cells that enable imaging materials under simulated operational conditions, such as high temperature, mechanical loads and oxidizing atmospheres.Keywords: Micro-tomography, Porous media, Ablation

tomography

Spacecraft Micro-Vibration: A Survey of Problems, Experiences, Potential Solutions, and Some Lessons Learned

Predicting, managing, controlling, and testing spacecraft micro-vibrations due to on-board internal disturbance sources is a formidable multi-disciplinary systems engineering challenge, especially for those observatories hosting extremely sensitive optical sensor payloads with stringent requirements on allowable Line-of-Sight (LOS) jitter. In this paper some specific spacecraft micro-vibration engineering challenges will be introduced and described. Technical background context is provided with the inclusion of several illustrative examples of NASA and ESA missions (both past and present) where dynamic interactions have to be addressed and which have demanding payload instrument LOS jitter requirements. A general modeling, analysis, simulation, and test approach to address and solve the overall problem of spacecraft micro-vibrations is outlined. Recommended rules of thumb are presented to provide guidance for analysts on where to initiate and how to approach a new spacecraft micro-vibration design problem. A set of experience based spacecraft micro-vibration lessons learned are also presented in the hope they can be leveraged on new system development projects to help overcome unfamiliarity with previously identified micro-vibration technical pitfalls and challenges.

Alvarez-Salazar, Oscar S.

Computing the effective elasticity of anisotropic porous media from X-ray computed micro-tomography images

Development and optimization of composite materials designed for thermal protection of NASA’s spacecraft requires the understanding of their physical response to high-enthalpy environments. To predict their macro-scale properties and behavior, high-fidelity 3D simulations are performed at the micro-scale on realistic representations of these composites. The digital micro-structures are generated either synthetically or through X-ray micro-tomography reconstructions. One of the main challenges in the prediction of heatshield material structural response is the computation of the effective elasticity of the fibrous composite, as well as the understanding of the deformation and stresses generated at the micro-scale. These are driven by the fiber layout within the micro-structure and the distribution of the infused matrix. In this effort, the micro-mechanical linear elastic behavior of fibrous ablators is modeled through the use of a numerical method based on the Multi-Point Stress Approximation (MPSA) finite volume scheme. The MPSA, a generalization of the more commonly used Multi-Point Flux Approximation (MPFA), was discussed in a previous presentation at the 15th USCCN and in reference. To predict the behavior of fibrous and woven architectures, algorithms that compute the local fiber orientation are used. The implementation of the MPSA was verified using analytical solutions, engineering test cases and compared against legacy Finite Element Analysis (FEA) software. The stress analysis models were then applied to real geometries used by NASA in thermal protection systems such as fibrous preforms and woven materials and the results were compared to experimental data.

Federico Semeraro

Micro-Pixel Image Position Sensing Testbed

The search for Earth-mass planets in the habitable zones of nearby Sun-like stars is an important goal of astrophysics. This search is not feasible with the current slate of astronomical instruments. We propose a new concept for microarcsecond astrometry which uses a simplified instrument and hence promises to be low cost. The concept employs a telescope with only a primary, laser metrology applied to the focal plane array, and new algorithms for measuring image position and displacement on the focal plane. The required level of accuracy in both the metrology and image position sensing is at a few micro-pixels. We have begun a detailed investigation of the feasibility of our approach using simulations and a micro-pixel image position sensing testbed called MCT. So far we have been able to demonstrate that the pixel-to-pixel distances in a focal plane can be measured with a precision of 20 micro-pixels and image-to-image distances with a precision of 30 micro-pixels. We have also shown using simulations that our image position algorithm can achieve accuracy of 4 micro-pixels in the presence of lambda/20 wavefront errors.

astrometry