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All sourcesNASA NTRSDOE OSTI
NASA NTRS2025

Considerations for Optimal Sensor Placement for Higher Accuracy Object Localization for Urban Air Mobility

Previous research into object localization has shown that sensor placement and alignment plays an important role in achieving higher accuracy levels of the estimated location of a tracked Urban Air Mobility Vehicle. In general, a near-orthogonal intersection between the ground node observation vectors results in the highest accuracy due to a smaller overlapping uncertainty region between both. This applies to triangulation by means of ground node camera angle observations as well as trilateration by means of ground node distance measurements. However, this simple concept is not easily fulfilled with a network of a limited number of static ground nodes and a moving object to be localized. This case study performs sensitivity analyses and explores practical ways on how to achieve higher estimate accuracy levels in this context.

sensor placement↗
NASA NTRS1995

NASA-UVA light aerospace alloy and structures technology program (LA2ST)

The NASA-UVa Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. Projects are being conducted by graduate students and faculty advisors in the Department of Materials Science and Engineering, as well as in the Department of Civil Engineering and Applied Mechanics, at the University of Virginia. Here, we report on progress achieved between July 1 and December 31, 1994. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies.

Starke, Edgar A., Jr.↗
NASA NTRS2011

Current Technology Development Efforts on the International X-Ray Observatory

The International X-ray Observatory (IXO) is a collaboration between NASA, ESA, and JAXA which is under study for launch in 2021. IXO will be a large 6600 kilogram Great Observatory-class mission which will build upon the legacies of the Chandra and XMM-Newton X-ray observatories. There is an extensive ongoing effort to raise the technology readiness level of the X-ray mirror from TRL 3 to TRL 6 in the next decade. Improvements have recently been made in the area of positioning and bonding mirrors on the nanometer scale and developing metals and composites with a matching coefficient of thermal expansion to the glass X-ray mirrors. On the mission systems side, the NASA reference design has been through a preliminary coupled loads analysis and a STOP analysis of the flight mirror assembly has been initiated. An impact study was performed comparing launching IXO on an Ariane 5 or a U.S. EELV. This paper will provide a snapshot of NASA's current observatory configuration and summarize the progress of these various technology and design efforts.

Robinson, David↗
NASA NTRS2015

Monitoring Changes of Tropical Extreme Rainfall Events Using Differential Absorption Barometric Radar (DiBAR)

This work studies the potential of monitoring changes in tropical extreme rainfall events such as tropical storms from space using a Differential-absorption BArometric Radar (DiBAR) operating at 50-55 gigahertz O2 absorption band to remotely measure sea surface air pressure. Air pressure is among the most important variables that affect atmospheric dynamics, and currently can only be measured by limited in-situ observations over oceans. Analyses show that with the proposed radar the errors in instantaneous (averaged) pressure estimates can be as low as approximately 5 millibars (approximately 1 millibar) under all weather conditions. With these sea level pressure measurements, the forecasts, analyses and understanding of these extreme events in both short and long time scales can be improved. Severe weathers, especially hurricanes, are listed as one of core areas that need improved observations and predictions in WCRP (World Climate Research Program) and NASA Decadal Survey (DS) and have major impacts on public safety and national security through disaster mitigation. Since the development of the DiBAR concept about a decade ago, our team has made substantial progress in advancing the concept. Our feasibility assessment clearly shows the potential of sea surface barometry using existing radar technologies. We have developed a DiBAR system design, fabricated a Prototype-DiBAR (P-DiBAR) for proof-of-concept, conducted lab, ground and airborne P-DiBAR tests. The flight test results are consistent with our instrumentation goals. Observational system simulation experiments for space DiBAR performance show substantial improvements in tropical storm predictions, not only for the hurricane track and position but also for the hurricane intensity. DiBAR measurements will lead us to an unprecedented level of the prediction and knowledge on tropical extreme rainfall weather and climate conditions.

Lin, Bing↗
NASA NTRS2002

Institute for Scientific and Educational Technology (ISET)-Education, Research and Training Programs in Engineering and Sciences

The 'Institute for Scientific and Educational Technology' has been established to provide a mechanism through which universities and other research organizations may cooperate with one another and with different government agencies and industrial organizations to further and promote research, education, and training programs in science, engineering, and related fields. This effort has been undertaken consistent with the national vision to 'promote excellence in America s educational system through enhancing and expanding scientific and technological competence.' The specific programs are directed in promoting and achieving excellence for individuals at all levels (elementary and secondary schools, undergraduate and graduate education, and postdoctoral and faculty research). The program is consistent with the existing activities of the Institute for Computational and Applied Mechanics (ICAM) and the American Society for Engineering Education (ASEE) at NASA Langley Research Center (LaRC). The efforts will be directed to embark on other research, education, and training activities in various fields of engineering, scientific, and educational technologies. The specific objectives of the present program may be outlined briefly as follows: 1) Cooperate in the various research, education, and technology programs of the Office of Education at LaRC. 2) Develop procedures for interactions between precollege, college, and graduate students, and between faculty and students at all levels. 3) Direct efforts to increase the participation by women and minorities in educational programs at all levels. 4) Enhance existing activities of ICAM and ASEE in education, research, and training of graduate students and faculty. 5) Invite distinguished scholars as appropriate and consistent with ISET goals to spend their summers and/or sabbaticals at NASA Langley andor ODU and interact with different researchers and graduate students. Perform research and administrative activities as needed to carry out the above mentioned activities. 6) The implementation of various activities of the ISET programs is carried out through cooperative efforts between Old Dominion University (ODU) and the Office of Education at LaRC. At present, major efforts are directed on the following ISET Programs: ICAM Programs, Academic Programs, Educational Research, Outreach Programs, Educational Technology and Cooperative Programs. These programs are described in the following sections.

Tiwari, S. N.↗
NASA NTRS2009

Space Suit Environment Testing of the Orion Atmosphere Revitalization Technology

An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Orion Atmosphere Revitalization System (ARS). In two previous years at this conference, reports were presented on extensive Johnson Space Center (JSC) testing of this technology in a sea-level pressure environment with simulated human metabolic loads. Another paper at this year s conference discusses similar testing with real human metabolic loads, including some closed-loop testing with emergency breathing masks. The Orion ARS is designed to also support extravehicular activity operations from a depressurized cabin. The next step in developmental testing at JSC was, therefore, to test this ARS technology in a typical closed space suit loop environment with low-pressure pure oxygen inside the process loop and vacuum outside the loop. This was the first instance of low-pressure oxygen loop testing of a new Orion ARS technology, and was conducted with simulated human metabolic loads in December 2008. The test investigated pressure drops through two different styles of prototype suit umbilical connectors and general swing-bed performance with both umbilical configurations as well as with a short jumper line installed in place of the umbilicals. Other interesting results include observations on the thermal effects of swing-bed operation in a vacuum environment and a recommendation of cycle time to maintain acceptable atmospheric CO2 and moisture levels.

Lin, Amy↗
NASA NTRS2015

Microelectrospray Thrusters

Propulsion technology is often a critical enabling technology for space missions. NASA is investing in technologies to enable high value missions with very small spacecraft, even CubeSats. However, these nanosatellites currently lack any appreciable propulsion capability. CubeSats are typically deployed and tumble or drift without any ability to transfer to higher value orbits, perform orbit maintenance, or perform de-orbit. Larger spacecraft can also benefit from high precision attitude control systems. Existing practices include reaction wheels with lifetime concerns and system level complexity. Microelectrospray thrusters will provide new propulsion capabilities to address these mission needs. Electric propulsion is an approach to accelerate propellant to very high exhaust velocities through the use of electrical power. Typical propulsion systems are limited to the combustion energy available in the chemical bonds of the fuel and then acceleration through a converging diverging nozzle. However, electric propulsion can accelerate propellant to ten times higher velocities and therefore increase momentum transfer efficiency, or essentially, increase the fuel economy. Fuel efficiency of thrusters is proportional to the exhaust velocity and referred to as specific impulse (Isp). The state-of-the-art (SOA) for CubeSats is cold gas propulsion with an Isp of 50-80 s. The Space Shuttle main engine demonstrated a specific impulse of 450 s. The target Isp for the Mars Exploration Program (MEP) systems is >1,500 s. This propellant efficiency can enable a 1-kg, 10-cm cube to transfer from low-Earth orbit to interplanetary space with only 200 g of propellant. In September 2013, NASA's Game Changing Development program competitively awarded three teams with contracts to develop MEP systems from Technology Readiness Level-3 (TRL-3), experimental concept, to TRL-5, system validation in a relevant environment. The project is planned for 18 months of system development. Due to the ambitious project goals, NASA has awarded contracts to mature three unique methods to achieve the desired goals. Some of the MEP concepts have been developed for more than a decade at the component level, but are now ready for system maturation. The three concepts include the high aspect ratio porous surface (HARPS) microthruster system, the scalable ion electrospray propulsion system (S-iEPS), and an indium microfluidic electrospray propulsion system. The HARPS system is under development by Busek Co. The HARPS thruster is an electrospray thruster that relies on surface emission of a porous metal with a passive capillary wicking system for propellant management. The HARPS thruster is expected to provide a simple, high ΔV and low-cost solution. The HARPS thruster concept is shown in figure 1. Figure 1 includes the thruster, integrated power processing unit, and propellant reservoir.

Dankanich, John↗
DOE OSTI2021

EBSD of Rough Native CuInGaSe2 Thin-Films

The polycrystalline Cu (In, Ga) Se2, or CIGS, based thin-film materials system has long been studied for use in photovoltaic technologies, where its bandgap tunability, mechanical flexibility, and relatively low production costs are all appealing. Nonetheless, significant defect populations, which serve to reduce efficiency, create performance instabilities, and increase concerns about long-term reliability, have hindered wide-scale adoption. Prior work, including application of a scanning probe based deep level trap spectroscopy (SP-DLTS) defect mapping technique and scanning transmission electron microscope (STEM) based electron energy loss spectroscopy (EELS), has shown that the most detrimental defects, with energy level near mid-gap (thus serving as a carrier recombination center), are most likely caused by CuIn/Ga antisites and tend to cluster at or around certain grain boundaries [1,2]. However, the exact nature of these particular boundaries — their structures, chemistries, or even the relative misorientation of their associated grains — and their relation to this defect clustering and/or its formation is yet unknown. As such, electron backscatter diffraction (EBSD) orientation mapping, directly correlated with defect-sensitive techniques like SP-DLTS and/or STEM-EELS, could prove critical for providing the final missing links toward understanding the mechanisms behind these defects. Indeed, recent studies using correlative electron beam induced current (EBIC) with EBSD have been able to identify boundaries, and their relative misorientations, that possess detrimental electronic properties [3]. However, because EBIC is unable to resolve the defect energy levels, many questions are left unanswered. Furthermore, this study, and others like it, employed focused ion beam (FIB) milling to flatten the natively-rough CIGS [3-5], which may run the risk of changing the nature of any near-surface defect structures.

14 SOLAR ENERGY↗
DOE OSTI2022

Field-Deployable Quantum Memory for Quantum Networking

High-performance quantum memories are an essential component for regulating temporal events in quantum networks. As a component in quantum-repeaters, they have the potential to support the distribution of entanglement beyond the physical limitations of fiber loss. This will enable key applications such as quantum key distribution, network-enhanced quantum sensing, and distributed quantum computing. Here, we present a quantum memory engineered to meet real-world deployment and scaling challenges. The memory technology utilizes a warm rubidium vapor as the storage medium, and operates at room temperature, without the need for vacuum- and/or cryogenic- support. Here, we demonstrate performance specifications of high-fidelity retrieval (95%) and low operation error (10 –2 ) at a storage time of 160 µs for single-photon level quantum memory operations. We further show a substantially improved storage time (with classical-level light) of up to 1ms by suppressing atomic diffusions. The device is housed in an enclosure with a standard 2U rackmount form factor, and can robustly operate on a day scale in a noisy environment. This result marks an important step toward implementing quantum networks in the field.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS1974

Long Life Technology Work at Rockwell International Space Division

This paper presents highlights of long-life technology oriented work performed at the Space Division of Rockwell International Corporation under contract to NASA. This effort included evaluation of Saturn V launch vehicle mechanical and electromechanical components for potential extended life capabilities, endurance tests, and accelerated aging experiments. A major aspect was evaluation of the components at the subassembly level (i.e., at the interface between moving surfaces) through in-depth wear analyses and assessments. Although some of this work is still in progress, preliminary conclusions are drawn and presented, together with the rationale for each. The paper concludes with a summary of the effort still remaining.

D K Huzel↗
NASA NTRS1981

Integrated Application of Active Controls (IAAC) Technology to an Advanced Subsonic Transport: Project Plan

The state of the art of active controls technology (ACT) and a recommended ACT development program plan are reviewed. The performance benefits and cost of ownership of an integrated application of ACT to civil transport aircraft is to be assessed along with the risk and laboratory and/or flight experiments designed to reduce the technical risks to a commercially acceptable level.

Source record↗
NASA NTRS1987

Threat expert system technology advisor

A prototype expert system was developed to determine the feasibility of using expert system technology to enhance the performance and survivability of helicopter pilots in a combat threat environment while flying NOE (Nap of the Earth) missions. The basis for the concept is the potential of using an Expert System Advisor to reduce the extreme overloading of the pilot who flies NOE mission below treetop level at approximately 40 knots while performing several other functions. The ultimate goal is to develop a Threat Expert System Advisor which provides threat information and advice that are better than even a highly experienced copilot. The results clearly show that the NOE pilot needs all the help in decision aiding and threat situation awareness that he can get. It clearly shows that heuristics are important and that an expert system for combat NOE helicopter missions can be of great help to the pilot in complex threat situations and in making decisions.

Kurrasch, E. R.↗
NASA NTRS1998

Learning from Automation Surprises and "Going Sour" Accidents: Progress on Human-Centered Automation

Advances in technology and new levels of automation on commercial jet transports has had many effects. There have been positive effects from both an economic and a safety point of view. The technology changes on the flight deck also have had reverberating effects on many other aspects of the aviation system and different aspects of human performance. Operational experience, research investigations, incidents, and occasionally accidents have shown that new and sometimes surprising problems have arisen as well. What are these problems with cockpit automation, and what should we learn from them? Do they represent over-automation or human error? Or instead perhaps there is a third possibility - they represent coordination breakdowns between operators and the automation? Are the problems just a series of small independent glitches revealed by specific accidents or near misses? Do these glitches represent a few small areas where there are cracks to be patched in what is otherwise a record of outstanding designs and systems? Or do these problems provide us with evidence about deeper factors that we need to address if we are to maintain and improve aviation safety in a changing world? How do the reverberations of technology change on the flight deck provide insight into generic issues about developing human-centered technologies and systems (Winograd and Woods, 1997)? Based on a series of investigations of pilot interaction with cockpit automation (Sarter and Woods, 1992; 1994; 1995; 1997a, 1997 b), supplemented by surveys, operational experience and incident data from other studies (e.g., Degani et al., 1995; Eldredge et al., 1991; Tenney et al., 1995; Wiener, 1989), we too have found that the problems that surround crew interaction with automation are more than a series of individual glitches. These difficulties are symptoms that indicate deeper patterns and phenomena concerning human-machine cooperation and paths towards disaster. In addition, we find the same kinds of patterns behind results from studies of physician interaction with computer-based systems in critical care medicine (e.g., Moll van Charante et al., 1993; Obradovich and Woods, 1996; Cook and Woods, 1996). Many of the results and implications of this kind of research are synthesized and discussed in two comprehensive volumes, Billings (1996) and Woods et al. (1994). This paper summarizes the pattern that has emerged from our research, related research, incident reports, and accident investigations. It uses this new understanding of why problems arise to point to new investment strategies that can help us deal with the perceived "human error" problem, make automation more of a team player, and maintain and improve safety.

Woods, David D.↗
NASA NTRS2001

STEP-AIRSEDS System Engineering Support

This report summarizes and highlights the activities in support of the Space Transportation using Electrodynamic Propulsion Atmospheric Ionospheric Research Small Expendable Deployer Satellite (STEP-AIRSEDS) Project for the period of May 16, 2000 through September 28, 2001. The Alpha Technology, Inc. was tasked to provide support to the MSFC (Marshall Space Flight Center) in requirements development and in verification activities. Specifically, the Alpha Technology, Inc. task was to: (1) develop and maintain the STEP-AIRSEDS Project System Requirements Database; (2) develop and maintain the STEP-AIRSEDS requirements verification definition and planning support database; (3) perform requirements flow down analysis of STEP-AIRSEDS Project System Requirements to TMTC (The Michigan Technic Corporation) Level IV Requirements; (4) provide system engineering guidance to the Project as needed; (5) provide guidance to TMTC in preparation of Level IV Requirements; and (6) provide support to STEP-AIRSEDS meetings, reviews, and telecons as needed.

Rowell, Tom↗
NASA NTRS2002

Development of the Ultra-Light Stretched Lens Array

At the last IEEE (Institute of Electrical and Electronics Engineers) PVSC (Photovoltaic Specialists Conference), the new stretched lens array (SLA) concept was introduced. Since that conference, the SLA team has made significant advances in the SLA technology, including component level improvements, array level optimization, space environment exposure testing, and prototype hardware fabrication and evaluation. This paper will describe the evolved version of the SLA, highlighting the improvements in the lens, solar cell, rigid panel structure, and complete solar array wing. The near term SLA will provide outstanding wing level performance: greater than 180 W/kg specific power, greater than 300 W/sq m power density, greater than 300 V operational voltage, and excellent durability in the space environment.

O'Neill, M. J.↗
NASA NTRS1997

Microstrip Reflectarray with Elements Having Variable Rotation Angles

Two Ka-band, half-meter diameter, circularly polarized microstrip reflectarrays have been developed. One has identical square patches with variable-length phase delay lines. The other uses identical square patches and delay lines with variable element rotation angles. Although both antennas demonstrated excellent efficiencies, adequate bandwidths, and low average sidelobe and cross-pol levels, the one with variable rotation angles achieved superior overall performance. It is believed that these are electrically the largest microstrip reflectarrays (6924 elements with 42 dB gain) ever developed. It is also the first time that circular polarization has been actually demonstrated using microstrip patch elements. Recent advances in reflectarray technology include the following: An X-band 0.75 m diameter microstrip reflectarray using variable-length phase delay lines which demonstrated a relatively high efficiency of 70% with peak gain of 35 dB; a partial microstrip reflectarray with beam scanning capability; A 27 GHz 0.23m diameter microstrip reflectarray using variable-size patches which achieved a gain of 31 dB at an efficiency of 31%. All these reflectarrays have dual-linear and dual-circular polarization capabilities, but only linear polarizations were demonstrated.

Huang, John↗
NASA NTRS2002

Technology Development and Advanced Planning for Curation of Returned Mars Samples

NASA Johnson Space Center (JSC) curates extraterrestrial samples, providing the international science community with lunar rock and soil returned by the Apollo astronauts, meteorites collected in Antarctica, cosmic dust collected in the stratosphere, and hardware exposed to the space environment. Curation comprises initial characterization of new samples, preparation and allocation of samples for research, and clean, secure long-term storage. The foundations of this effort are the specialized cleanrooms (class 10 to 10,000) for each of the four types of materials, the supporting facilities, and the people, many of whom have been doing detailed work in clean environments for decades. JSC is also preparing to curate the next generation of extraterrestrial samples. These include samples collected from the solar wind, a comet, and an asteroid. Early planning and R\&D are underway to support post-mission sample handling and curation of samples returned from Mars. One of the strong scientific reasons for returning samples from Mars is to search for evidence of current or past life in the samples. Because of the remote possibility that the samples may contain life forms that are hazardous to the terrestrial biosphere, the National Research Council has recommended that all samples returned from Mars be kept under strict biological containment until tests show that they can safely be released to other laboratories. It is possible that Mars samples may contain only scarce or subtle traces of life or prebiotic chemistry that could readily be overwhelmed by terrestrial contamination . Thus, the facilities used to contain, process, and analyze samples from Mars must have a combination of high-level biocontainment and organic / inorganic chemical cleanliness that is unprecedented. JSC has been conducting feasibility studies and developing designs for a sample receiving facility that would offer biocontainment at least the equivalent of current maximum containment BSL-4 (BioSafety Level 4) laboratories, while simultaneously maintaining cleanliness levels equaling those of state-of-the-art cleanrooms. Unique requirements for the processing of Mars samples have inspired a program to develop handling techniques that are much more precise and reliable than the approach (currently used for lunar samples) of employing gloved human hands in nitrogen-filled gloveboxes. Individual samples from Mars are expected to be much smaller than lunar samples, the total mass of samples returned by each mission being 0.5- 1 kg, compared with many tens of kg of lunar samples returned by each of the six Apollo missions. Smaller samples require much more of the processing to be done under microscopic observation. In addition, the requirements for cleanliness and high-level containment would be difficult to satisfy while using traditional gloveboxes. JSC has constructed a laboratory to test concepts and technologies important to future sample curation. The Advanced Curation Laboratory includes a new-generation glovebox equipped with a robotic arm to evaluate the usability of robotic and teleoperated systems to perform curatorial tasks. The laboratory also contains equipment for precision cleaning and the measurement of trace organic contamination.

Lindstrom, David J.↗
NASA NTRS2008

Aircraft System Analysis of Technology Benefits to Civil Transport Rotorcraft

An aircraft systems analysis was conducted to evaluate the net benefits of advanced technologies on two conceptual civil transport rotorcraft, to quantify the potential of future civil rotorcraft to become operationally viable and economically competitive, with the ultimate goal of alleviating congestion in our airways, runways and terminals. These questions are three of many that must be resolved for the successful introduction of civil transport rotorcraft: 1) Can civil transport rotorcraft actually relieve current airport congestion and improve overall air traffic and passenger throughput at busy hub airports? What is that operational scenario? 2) Can advanced technology make future civil rotorcraft economically competitive in scheduled passenger transport? What are those enabling technologies? 3) What level of investment is necessary to mature the key enabling technologies? This study addresses the first two questions, and several others, by applying a systems analysis approach to a broad spectrum of potential advanced technologies at a conceptual level of design. The method was to identify those advanced technologies that showed the most promise and to quantify their benefits to the design, development, production, and operation of future civil rotorcraft. Adjustments are made to sizing data by subject matter experts to reflect the introduction of new technologies that offer improved performance, reduced weight, reduced maintenance, or reduced cost. This study used projected benefits from new, advanced technologies, generally based on research results, analysis, or small-scale test data. The technologies are identified, categorized and quantified in the report. The net benefit of selected advanced technologies is quantified for two civil transport rotorcraft concepts, a Single Main Rotor Compound (SMRC) helicopter designed for 250 ktas cruise airspeed and a Civil Tilt Rotor (CTR) designed for 350 ktas cruise airspeed. A baseline design of each concept was sized for a representative civil passenger transport mission, using current technology. Individual advanced technologies are quantified and applied to resize the aircraft, thereby quantifying the net benefit of that technology to the rotorcraft. Estimates of development cost, production cost and operating and support costs are made with a commercial cost estimating program, calibrated to Boeing products with adjustments for future civil production processes. A cost metric of cash direct operating cost per available seat-mile (DOC ASM) is used to compare the cost benefit of the technologies. The same metric is used to compare results with turboprop operating costs. Reduced engine SFC was the most advantageous advanced technology for both rotorcraft concepts. Structural weight reduction was the second most beneficial technology, followed by advanced drive systems and then by technology for rotorcraft performance. Most of the technologies evaluated in this report should apply similarly to conventional helicopters. The implicit assumption is that resources will become available to mature the technologies for fullscale production aircraft. That assumption is certainly the weak link in any forecast of future possibilities. The analysis serves the purpose of identifying which technologies offer the most potential benefit, and thus the ones that should receive the highest priority for continued development. This study directly addressed the following NASA Subsonic Rotary Wing (SRW) subtopics: SR W.4.8.I.J Establish capability for rotorcraft system analysis and SRW. 4.8.I.4 Conduct limited technology benefit assessment on baseline rotorcraft configurations.

Wilkerson, Joseph B.↗