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At least 775 records · Page 43

Advanced Space Suit Insulation Feasibility Study

For planetary applications, the space suit insulation has unique requirements because it must perform in a dynamic mode to protect humans in the harsh dust, pressure and temperature environments. Since the presence of a gaseous planetary atmosphere adds significant thermal conductance to the suit insulation, the current multi-layer flexible insulation designed for vacuum applications is not suitable in reduced pressure planetary environments such as that of Mars. Therefore a feasibility study has been conducted at NASA to identify the most promising insulation concepts that can be developed to provide an acceptable suit insulation. Insulation concepts surveyed include foams, microspheres, microfibers, and vacuum jackets. The feasibility study includes a literature survey of potential concepts, an evaluation of test results for initial insulation concepts, and a development philosophy to be pursued as a result of the initial testing and conceptual surveys. The recommended focus is on microfibers due to the versatility of fiber structure configurations, the wide choice of fiber materials available, the maturity of the fiber processing industry, and past experience with fibers in insulation applications

Trevino, Luis A.↗

Development of a Multi-Disciplinary Aerothermostructural Model Applicable to Hypersonic Flight

The harsh and complex hypersonic flight environment has driven design and analysis improvements for many years. One of the defining characteristics of hypersonic flight is the coupled, multi-disciplinary nature of the dominant physics. In an effect to examine some of the multi-disciplinary problems associated with hypersonic flight engineers at the NASA Dryden Flight Research Center developed a non-linear 6 degrees-of-freedom, full vehicle simulation that includes the necessary model capabilities: aerothermal heating, ablation, and thermal stress solutions. Development of the tool and results for some investigations will be presented. Requirements and improvements for future work will also be reviewed. The results of the work emphasize the need for a coupled, multi-disciplinary analysis to provide accurate

hypersonics↗

Design and Operation of a Fast, Thin-Film Thermocouple Probe on a Turbine Engine

As a demonstration of technology maturation, a thin-film temperature sensor probe was fabricated and installed on a F117 turbofan engine via a borescope access port to monitor the temperature experienced in the bleed air passage of the compressor area during an engine checkout test run. To withstand the harsh conditions experienced in this environment, the sensor probe was built from high temperature materials. The thin-film thermocouple sensing elements were deposited by physical vapor deposition using pure metal elements, thus avoiding the inconsistencies of sputter-depositing particular percentages of materials to form standardized alloys commonly found in thermocouples. The sensor probe and assembly were subjected to a strict protocol of multi-axis vibrational testing as well as elevated temperature pressure testing to be qualified for this application. The thin-film thermocouple probe demonstrated a faster response than a traditional embedded thermocouple during the engine checkout run.

thermocouples↗

Power Subsystem Approach for the Europa Mission

NASA is planning to launch a spacecraft on a mission to the Jovian moon Europa, in order to conduct a detailed reconnaissance and investigation of its habitability. The spacecraft would orbit Jupiter and perform a detailed science investigation of Europa, utilizing a number of science instruments including an ice-penetrating radar to determine the icy shell thickness and presence of subsurface oceans. The spacecraft would be exposed to harsh radiation and extreme temperature environments. To meet mission objectives, the spacecraft power subsystem is being architected and designed to operate efficiently, and with a high degree of reliability.

Ulloa-Severino, Antonio↗

Power Subsystem Approach for The Europa Mission

NASA is planning to launch a spacecraft on a mission to the Jovian moon Europa, in order to conduct a detailed reconnaissance and investigation of its habitability. The spacecraft would orbit Jupiter and perform a detailed science investigation of Europa, utilizing a number of science instruments including an ice-penetrating radar to determine the icy shell thickness and presence of subsurface oceans. The spacecraft would be exposed to harsh radiation and extreme temperature environments. To meet mission objectives, the spacecraft power subsystem is being architected and designed to operate efficiently, and with a high degree of reliability.

Ulloa-Severino, Antonio↗

Artemis Navigation Architecture: Early Capabilities and Long Term Evolvability and Evolution

With the awarding of multiple contracts within the Artemis program and building on the success of Artemis I, NASA is investing in and demonstrating the vehicle capabilities necessary for a return to human crewed Lunar Missions. To support activities on the lunar surface, NASA is also assessing architecture options and approaches to enable high precision in-situ navigation within the lunar sphere of influence. These capabilities build on decades of research and advancements within the field, building and evolving the techniques used during Apollo. To support inter-operability and broad application within its elements, NASA conducted a trade on Orbital and Surface Lunar Architecture for PNT. Time-defined mission requirements were captured across elements to inform a phased approach and deployment of needed capability. The architecture must also address unique aspects of the South Pole lunar environments, specifically in terms of harsh lighting and hazardous terrain. To inform the study, documentation of primary users, operational concepts of operations, driving scenarios, and mission needs were used to define performance constraints and phasing. Multiple technologies were assessed in terms of maturity, applicability, and performance to meet the primary user needs forecast. The results of this study support the utilization of in-situ orbital infrastructure to provide a back-bone for navigation and emphasize the need for a common Lunar Reference System and Lunar Time Reference. This deployment can ensure compatibility and enable a high-accuracy in-situ capability. This provides further justification for the capabilities being invested in and deployed by NASA and other international agencies. In addition to including advancements in terrestrial surface navigation, NASA is also applying lessons learned and innovation in the contractual approach to the individual elements by means of a services-based contract mechanism. This impacts the navigation architecture heavily in terms of government and provider roles, in terms of levels of implementation, interoperability, and verification. These distinctions in roles provide constraints to the architecture approach in terms of implementation and integration and will be discussed. The development, use, and mandate of interoperability standards are being deployed to support cross-element compatibility. This paper will provide a summary of the NASA Lunar Navigation needs across its various elements and the proposed deployment of an integrated navigation architecture to support early mission needs with inherent extensibility towards the future.

Evan Anzalone↗

Reconfigurable Computing Concepts for Space Missions: Universal Modular Spares

Computing hardware for control, data collection, and other purposes will prove many times over crucial resources in NASA's upcoming space missions. Ability to provide these resources within mission payload requirements, with the hardiness to operate for extended periods under potentially harsh conditions in off-World environments, is daunting enough without considering the possibility of doing so with conventional electronics. This paper examines some ideas and options, and proposes some initial approaches, for logical design of reconfigurable computing resources offering true modularity, universal compatibility, and unprecedented flexibility to service all forms and needs of mission infrastructure.

Patrick, M. Clinton↗

Microorganisms in the Stratosphere (MIST): In-flight Sterilization with UVC Leds

The stratosphere (10 km to 50 km above sea level) is a unique place on Earth for astrobiological studies of microbes in extreme environments due to the combination of harsh conditions (high ultraviolet radiation, low pressure, desiccation, and low temperatures). Microorganisms in the Stratosphere (MIST) will attempt to characterize the diversity of microbes at these altitudes using a balloon collection device on a meteorological weather balloon. A major challenge of such an aerobiology study is the potential for ground contamination that makes it difficult to distinguish between collected microbes and contaminants. One solution is to use germicidal ultraviolet light emitting diodes (UV LEDs) to sterilize the collection strip. To use this solution, an optimal spatial arrangement of the lights had to be determined to ensure the greatest chance of complete sterilization within the 30 to 60 minute time of balloon ascent. A novel, 3D-printed test stand was developed to experimentally determine viable Bacillus pumilus SAFR-032 spore reduction after exposure to ultraviolet radiation at various times, angles, and distances. Taken together, the experimental simulations suggested that the UV LEDs on the MIST flight hardware should be active for at least 15 minutes and mounted within 4 cm of the illuminated surface at any angle to achieve optimal sterilization. These findings will aid in the production of the balloon collection device to ensure pristine stratospheric microbial samples are collected. Flight hardware capable of in-flight self-sterilization will enable future life detection missions to minimize both forward contamination and false positives.

Exobiology↗

RASSOR - Regolith Advanced Surface Systems Operations Robot

The Regolith Advanced Surface Systems Operations Robot (RASSOR) is a lightweight excavator for mining in reduced gravity. RASSOR addresses the need for a lightweight (<100 kg) robot that is able to overcome excavation reaction forces while operating in reduced gravity environments such as the moon or Mars. A nominal mission would send RASSOR to the moon to operate for five years delivering regolith feedstock to a separate chemical plant, which extracts oxygen from the regolith using H2 reduction methods. RASSOR would make 35 trips of 20 kg loads every 24 hours. With four RASSORs operating at one time, the mission would achieve 10 tonnes of oxygen per year (8 t for rocket propellant and 2 t for life support). Accessing craters in space environments may be extremely hard and harsh due to volatile resources - survival is challenging. New technologies and methods are required. RASSOR is a product of KSC Swamp Works which establishes rapid, innovative and cost effective exploration mission solutions by leveraging partnerships across NASA, industry and academia.

Regolith↗

Effect of Ram and Zenith Exposure on the Optical Properties of Polymers in Space

The temperature of spacecraft is influenced by the solar absorptance and thermal emittance of the external spacecraft materials. Optical and thermal properties can degrade over time in the harsh low Earth orbital (LEO) space environment where spacecraft external materials are exposed to various forms of radiation, thermal cycling, and atomic oxygen. Therefore, it is important to test the durability of spacecraft materials in the space environment. One objective of the Polymers and Zenith Polymers Experiments was to determine the effect of LEO space exposure on the optical properties of various spacecraft polymers. These experiments were flown as part of the Materials International Space Station Experiment 7 (MISSE 7) mission on the exterior of the International Space Station (ISS) for 1.5 years. Samples were flown in ram, wake or zenith directions, receiving varying amounts of atomic oxygen and solar radiation exposure. Total and diffuse reflectance and transmittance of flight and corresponding control samples were obtained post-flight using a Cary 5000 UV-Vis-NIR Spectrophotometer. Integrated air mass zero solar absorptance (s) of the flight and control samples were computed from the total transmittance and reflectance, and compared. The optical data are compared with similar polymers exposed to space for four years as part of MISSE 2, and with atomic oxygen erosion data, to help understand the degradation of these polymers in the space environment. Results show that prolonged space exposure increases the solar absorptance of some materials. Knowing which polymers remain stable will benefit future spacecraft design.

Yuanchun Li↗

Novel Super-Elastic Materials for Advanced Bearing Applications

Tribological surfaces of mechanical components encounter harsh conditions in terrestrial, marine and aerospace environments. Brinell denting, abrasive wear and fatigue often lead to life-limiting bearing and gear failures. Novel superelastic materials based upon Ni-Ti alloys are an emerging solution. Ni-Ti alloys are intermetallic materials that possess characteristics of both metals and ceramics. Ni-Ti alloys have intrinsically good aqueous corrosion resistance (they cannot rust), high hardness, relatively low elastic modulus, are chemically inert and readily lubricated. Ni-Ti alloys also belong to the family of superelastics and, despite high hardness, are able to withstand large strains without suffering permanent plastic deformation. In this paper, the use of hard, resilient Ni-Ti alloys for corrosion-proof, shockproof bearing and gear applications are presented. Through a series of bearing and gear development projects, it is demonstrated that Ni-Tis unique blend of materials properties lead to significantly improved load capacity, reduced weight and intrinsic corrosion resistance not found in any other bearing materials. Ni-Ti thus represents a new materials solution to demanding tribological applications.

materials↗

Durability of Polymers in the Space Environment

Spacecraft in low Earth orbit (LEO) are subjected to harsh environmental conditions, including radiation (cosmic rays, ultraviolet, x-ray, and charged particle radiation), micrometeoroids and orbital debris, temperature extremes, thermal cycling, and atomic oxygen (AO). These environmental exposures can result in erosion, embrittlement and optical property degradation, threatening spacecraft performance and durability. While all of these environmental exposures can cause degradation to spacecraft components, AO is a particularly serious structural, thermal, and optical threat, to exterior oxidizable spacecraft materials, such as polymers. To further our understanding of AO erosion and radiation embrittlement of spacecraft materials, NASA Glenn Research Center has developed and flown a series of experiments as part of the Materials International Space Station Experiment (MISSE) missions on the exterior of the International Space Station (ISS). In continuing these studies, three new Glenn experiments have accepted for flight on the new ISS MISSE-Flight Facility (MISSE-FF). The Polymers and Composites Experiment (PCE) is being flown as part of the MISSE-9 inaugural mission of MISSE-FF. The Polymers and Composites Experiment-2 (PCE-2) and Polymers and Composites-3 Experiment (PCE-3) are being flown as part of the MISSE-10 and MISSE-12 missions, respectively. This presentation provides an overview of the Glenn's three MISSE-FF flight experiments including the objectives and initial spaceflight results.

spaceflight↗

TPSAS-NF1676L-11812-DND

Reducing the weight of spacecraft will reduce the fabrication costs and the launch costs . The elimination of wiring and wiring harnesses reduces the total mass of the vehicle . Wireless sensor technology can reduce the weight and therefore the costs of spacecraft . The Decadal Survey of Civil Aeronautics survey identified that "self-powered, wireless microelectromechanical sensors" warrant attention over the next decade . Current wireless sensor systems have low data rates and require batteries. The environment of aerospace vehicles is often very harsh, with temperature extremes ranging from cryogenic to very high temperatures during re-entry. For example, X-37B mini unmanned shuttle will require high temperature sensors mounted on the structure, as well as cryogenic sensors for monitoring fuel tanks. Batteries do not work well in either temperature extremes. Also, sensors are typically located in internal structures with limited access, making the periodic changing of batteries costly and time consuming. Passive wireless sensors are needed that operate across an extremely large temperature range and do not require batteries. NASA recently instrumented an all Composite Crew Module for structural testing on the ground. Wireless sensors could have reduced the time to instrument the module and check out the sensor wiring.

W (Cy) Wilson↗

Artificial intelligence and the space station software support environment

In a software system the size of the Space Station Software Support Environment (SSE), no one software development or implementation methodology is presently powerful enough to provide safe, reliable, maintainable, cost effective real time or near real time software. In an environment that must survive one of the most harsh and long life times, software must be produced that will perform as predicted, from the first time it is executed to the last. Many of the software challenges that will be faced will require strategies borrowed from Artificial Intelligence (AI). AI is the only development area mentioned as an example of a legitimate reason for a waiver from the overall requirement to use the Ada programming language for software development. The limits are defined of the applicability of the Ada language Ada Programming Support Environment (of which the SSE is a special case), and software engineering to AI solutions by describing a scenario that involves many facets of AI methodologies.

Marlowe, Gilbert↗

Toward an IMU-Based Space Suit Motion Capture System

Spacesuits are complex engineering systems that sustain human health and enable performance outside Earth-like environments. These systems must support human mobility and physical workload demands while minimizing injury risk during extravehicular activity (EVA). Future EVA operations on the Lunar surface are expected to be more frequent and require higher physical workloads than previously during the ISS, Shuttle, and Apollo programs. To characterize the workloads and ergonomics needs a suit must support, the kinematics of the space suit must be measured during operationally-relevant tasks in ground analog environments. Kinematics capture of the suit is challenging for traditional optical motion capture (OMC) approaches due to marker occlusion, harsh lighting or environmental conditions, and tests with suit surrogates in outdoor field environments. To this end, engineers at NASA are developing the Augmented Suit Inverse Kinematics (ASIK) system, a complete motion capture method and inverse kinematics solver which relies solely on a network of wireless inertial measurement units (IMUs) attached to the major kinematic segments of the spacesuit. The ASIK modeling language allows for the simple inclusion of probabilistic priors such as suit size and shape or IMU poses. The ASIK system was tested in a 7-subject pilot study. Each subject donned NASA’s new prototype exploration spacesuit in the Active Response Gravity Offload System (ARGOS) facility at Johnson Space Center in Houston, TX. The suits were outfitted with 12 IMUs to estimate lower body and trunk kinematics. The suits were also outfitted with a set of reflective OMC markers, and traditional OMC data was collected and processed. Characterization of the ASIK-derived suit joint angles’ accuracy against an optical motion capture datum will be presented. Discussion of these results, as well as discussion of system calibration and nuances of mathematical observability, will be included.

IMU↗

Biaxial Testing of High-Strength Fabric Improves Design of Inflatable Radar Domes

Large radar installations around the globe continuously watch the skies, unobtrusively providing security to the United States; these systems have been in active use for the past 50 years. Often situated in extreme environments, the radar dishes require shielding from the harsh elements. Air-inflated domes (over 100 ft in diameter) are one structure of choice for providing this essential protection. The radomes are constructed from highstrength fabric that is strong enough to withstand the inflation pressure, high winds, and other environmental loads, yet transparent to the microwave signal to allow precise radar mapping. This fabric is woven from glass fibers for high strength and embedded in a polytetrafluoroethylene resin matrix, akin to the nonstick coatings used on cookware.

Krause, David L.↗

The membrane bioreactor (MBR): A hybrid technology for bioregenerative wastewater treatment and resource recovery in space

Extraplanetary surface habitat life support systems (LSS) on the Moon and Mars, as well as long-duration space travel, will require novel capabilities to withstand anticipated unique, harsh conditions. In order to provide safe, habitable environments for the crew, water purification and waste processing systems will be required to treat all sources of water (condensate, Sabatier, urine, hygiene, fecal, food waste) in order to achieve the necessary levels of recovery needed to sustain life over the long-duration missions. The ability to recycle organic wastes creates an opportunity to recover critical elements (e.g., C, H, O, N, P) for subsequent food production, water purification, and atmospheric regeneration. Bioregenerative systems mimic functions of nature in engineered systems, or bioreactors, utilizing combination of prokaryotes, eukaryotes and archaea. While these systems are commonly used on Earth for wastewater treatment, bioreactors for space travel face additional challenges. Terrestrial bioreactors often rely on gravitational settling of dense flocs and granules for cell retention. For micro- or partial-gravity environments, density differential alone will not be adequate for cell retention; a gravity-independent means for cell retention is crucial. The membrane bioreactor represents the state of the art in wastewater treatment. This hybrid system combines biological processes with membrane filtration to achieve performance beyond what each can accomplish individually. The complete cell retention in an MBR allows for the decoupling of hydraulic retention time (HRT) and solids retention time (SRT), which result in a high-thruput, compact, treatment system. The Bioregenerative Water Technology Team at NASA Kennedy Space Center and the University of South Florida has developed a bioregenerative platform based on the hybrid MBR technology. The overall architecture is compact, modular, flexible, and adaptable to mission evolutions. The main subsystems of the bioregenerative architecture include: 1) Anaerobic membrane bioreactor (AnMBR): Also termed the Organic processor assembly (OPA), the function of the AnMBR is to treat organic wastes such as fecal and food wastes. These wastes are characterized by a concentration of suspended solids comprised of carbohydrates, proteins and lipids. The assigned function of the AnMBR is to break down and covert suspended solids to biogas (methane, hydrogen and carbon dioxide), reduce effluent chemical oxygen demand (COD), liberate organically-bound nutrients, and remove pathogenic organisms. 2) Phototrophic membrane bioreactor (PMBR): The PMBR is comprised of a co-culture of microalgae and bacteria. The assigned function of the PMBR is to polish the permeate of the AnMBR to further remove dissolved organic carbon, manage nutrients (nitrogen transformation, load dampening), and perform air revitalization. 3) Food processor assembly (FPA): The FPA is a food production platform (prokaryotic or eukaryotic), fueled by outputs from the AnMBR, or PMBR. For the presentation, we will describe each step of the bioregenerative architecture, and present performance data from extended trials treating analog and real metabolic wastes.

Bioreactor↗

Lipid Biomarkers for a Hypersaline Microbial Mat Community

The use of lipid biomarkers and their carbon isotopic compositions are valuable tools for establishing links to ancient microbial ecosystems. As witnessed by the stromatolite record, benthic microbial mats grew in shallow water lagoonal environments where microorganisms had virtually no competition apart from the harsh conditions of hypersalinity, desiccation and intense light. Today, the modern counterparts of these microbial ecosystems find appropriate niches in only a few places where extremes eliminate eukaryotic grazers. Answers to many outstanding questions about the evolution of microorganisms and their environments on early Earth are best answered through study of these extant analogs. Lipids associated with various groups of bacteria can be valuable biomarkers for identification of specific groups of microorganisms both in ancient organic-rich sedimentary rocks (geolipids) and contemporary microbial communities (membrane lipids). Use of compound specific isotope analysis adds additional refinement to the identification of biomarker source, so that it is possible to take advantage of the 3C-depletions associated with various functional groups of organisms (i.e. autotrophs, heterotrophs, methanotrophs, methanogens) responsible for the cycling of carbon within a microbial community. Our recent work has focused on a set of hypersaline evaporation ponds at Guerrero Negro, Baja California Sur, Mexico which support the abundant growth of Microcoleus-dominated microbial mats. Specific biomarkers for diatoms, cyanobacteria, archaea, green nonsulfur (GNS), sulfate reducing, and methanotrophic bacteria have been identified. Analyses of the ester-bound fatty acids indicate a highly diverse microbial community, dominated by photosynthetic organisms at the surface.

Jahnke, Linda L.↗