Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “small projects”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,063 records · Page 59

The Successful Synergy of Swift and Fermi/GBM in Magnetars

The magnetar rate of discovery has increased dramatically in the last decade. Five sources were discovered in the last three years alone as a result of the very efficient synergy among three X- and .gamma-ray instruments on NASA satellites: the Swift/Burst Alert Telescope (BAT), the Fermi/Gamma ray Burst Monitor (GBM), and the Rossi X-Ray Timing Explorer; RXTE/Proportional Counter Array (PCA). To date, there are approx. 25 magnetar candidates, of which two are (one each) in the Large and Small Magellanic Cloud and the rest reside on the Galactic plane of our Milky Way. I will discuss here the main properties of the Magnetar Population and the common projects that can be achieved with the synergy of Swift and GBM.

Kouveliotou, Chryssa↗

Characterization of Electrochemically Generated Silver

Silver biocide offers a potential advantage over iodine, the current state of the art in US spacecraft disinfection technology, in that silver can be safely consumed by the crew. Low concentrations of silver (<500 ppb) have been shown to kill bacteria in water systems and keep it safe for potability. Silver does not require hardware to remove it from a water system, and therefore can provide a simpler means for disinfecting water. The Russian segment of the International Space Station has utilized an electrochemically generated silver solution, which is colloidal in nature. To be able to reliably provide a silver biocide to drinking water by electrochemical means would reduce mass required for removing another biocide such as iodine from the water. This would also aid in crew time required to replace iodine removal cartridges. Future long term missions would benefit from electrochemically produced silver as the biocide could be produced on demand and requires only a small concentration to be effective. Since it can also be consumed safely, there is less mass in removal hardware and little consumables required for production. The goal of this project initially is to understand the nature of the electrochemically produced silver, the particle sizes produced by the electrochemical cell and the effect that voltage adjustment has on the particle size. In literature, it has been documented that dissolved oxygen and pH have an effect on the ionization of the electrochemical silver so those parameters would be measured and possibly adjusted to understand their effect on the silver.

Adam, Niklas↗

Nuclear Thermal Rocket Simulation in NPSS

Four nuclear thermal rocket (NTR) models have been created in the Numerical Propulsion System Simulation (NPSS) framework. The models are divided into two categories. One set is based upon the ZrC-graphite composite fuel element and tie tube-style reactor developed during the Nuclear Engine for Rocket Vehicle Application (NERVA) project in the late 1960s and early 1970s. The other reactor set is based upon a W-UO2 ceramic-metallic (CERMET) fuel element. Within each category, a small and a large thrust engine are modeled. The small engine models utilize RL-10 turbomachinery performance maps and have a thrust of approximately 33.4 kN (7,500 lbf ). The large engine models utilize scaled RL-60 turbomachinery performance maps and have a thrust of approximately 111.2 kN (25,000 lbf ). Power deposition profiles for each reactor were obtained from a detailed Monte Carlo N-Particle (MCNP5) model of the reactor cores. Performance factors such as thermodynamic state points, thrust, specific impulse, reactor power level, and maximum fuel temperature are analyzed for each engine design.

Belair, Michael L.↗

Iodine Satellite

This project is a collaborative effort to mature an iodine propulsion system while reducing risk and increasing fidelity of a technology demonstration mission concept. 1 The FY 2014 tasks include investments leveraged throughout NASA, from multiple mission directorates, as a partnership with NASA Glenn Research Center (GRC), a NASA Marshall Space Flight Center (MSFC) Technology Investment Project, and an Air Force partnership. Propulsion technology is often a critical enabling technology for space missions. NASA is investing in technologies to enable high value missions with very small and low-cost spacecraft, even CubeSats. However, these small spacecraft currently lack any appreciable propulsion capability. CubeSats are typically deployed and drift without any ability to transfer to higher value orbits, perform orbit maintenance, or deorbit. However, the iodine Hall system can allow the spacecraft to transfer into a higher value science orbit. The iodine satellite (iSAT) will be able to achieve a (Delta)V of >500 m/s with <1 kg of solid iodine propellant, which can be stored in an unpressurized benign state prior to launch. The iSAT propulsion system consists of the 200 W Hall thruster, solid iodine propellant tank, a power processing unit, and the necessary valves and tubing to route the iodine vapor. The propulsion system is led by GRC, with critical hardware provided by the Busek Co. The propellant tank begins with solid iodine unpressurized on the ground and in-flight before operations, which is then heated via tank heaters to a temperature at which solid iodine sublimates to iodine vapor. The vapor is then routed through tubing and custom valves to control mass flow to the thruster and cathode assembly. 2 The thruster then ionizes the vapor and accelerates it via magnetic and electrostatic fields, resulting in thrust with a specific impulse >1,300 s. The iSAT spacecraft, illustrated in figure 1, is currently a 12U CubeSat. The spacecraft chassis will be constructed from aluminum with a finish to prevent iodine-driven corrosion. The iSAT spacecraft includes full three-axis control using wheels, magnetic torque rods, inertial management unit, and a suite of sensors and optics. The spacecraft will leverage heat generated by spacecraft components and radiators for a passive thermal control system.

Dankanich, John↗

NH11B-1726: FrankenRaven: A New Platform for Remote Sensing

Small, modular aircraft are an emerging technology with a goal to maximize flexibility and enable multi-mission support. This reports the progress of an unmanned aerial system (UAS) project conducted at the NASA Ames Research Center (ARC) in 2016. This interdisciplinary effort builds upon the success of the 2014 FrankenEye project to apply rapid prototyping techniques to UAS, to develop a variety of platforms to host remote sensing instruments. In 2016, ARC received AeroVironment RQ-11A and RQ-11B Raven UAS from the US Department of the Interior, Office of Aviation Services. These aircraft have electric propulsion, a wingspan of roughly 1.3m, and have demonstrated reliability in challenging environments. The Raven airframe is an ideal foundation to construct more complex aircraft, and student interns using 3D printing were able to graft multiple Raven wings and fuselages into FrankenRaven aircraft. Aeronautical analysis shows that the new configuration has enhanced flight time, payload capacity, and distance compared to the original Raven. The FrankenRaven avionics architecture replaces the mil-spec avionics with COTS technology based upon the 3DR Pixhawk PX4 autopilot with a safety multiplexer for failsafe handoff to 2.4 GHz RC control and 915 MHz telemetry. This project demonstrates how design reuse, rapid prototyping, and modular subcomponents can be leveraged into flexible airborne platforms that can host a variety of remote sensing payloads and even multiple payloads. Modularity advances a new paradigm: mass-customization of aircraft around given payload(s). Multi-fuselage designs are currently under development to host a wide variety of payloads including a zenith-pointing spectrometer, a magnetometer, a multi-spectral camera, and a RGB camera. After airworthiness certification, flight readiness review, and test flights are performed at Crows Landing airfield in central California, field data will be taken at Kilauea volcano in Hawaii and other locations.

remote sensing↗

Human Performance Contributions to Safety in Commercial Aviation

Every day in aviation, pilots, air traffic controllers, and other front-line personnel perform countless correct judgments and actions in a variety of operational environments. These judgments and actions are often the difference between an accident and a non-event. Ironically, data on these behaviors are rarely collected or analyzed. Data-driven decisions about safety management and design of safety-critical systems are limited by the available data, which influence how decision makers characterize problems and identify solutions. Large volumes of data are collected on the failures and errors that result in infrequent incidents and accidents, but in the absence of data on behaviors that result in routine successful outcomes, safety management and system design decisions are based on a small sample of nonrepresentative safety data. This assessment aimed to find and document “safety successes” made possible by human operators. With many Aeronautics Research Mission Directorate (ARMD) Programs and Projects focusing on increased automation and autonomy and decreased human involvement, failure to fully consider the human contributions to successful system performance in civil aviation represents a significant risk — a risk that has not been recognized to date. Without understanding how humans contribute to safety, any estimate of predicted safety of autonomous capabilities is incomplete and inherently suspect. Furthermore, understanding the ways in which humans contribute to safety can promote strategic interactions among safety technologies, functions, procedures and the people using them. Without this understanding, the full benefits of an integrated, optimized human/technology or autonomous system will not be realized. Historically, safety has been consistently defined in terms of the occurrence of accidents or recognized risks (i.e., in terms of things that go wrong). These adverse outcomes are explained by identifying their causes, and safety is restored by eliminating or mitigating these causes. An alternative to this approach is to focus on what goes right and identify how to replicate that process. Focusing on the rare cases of failures attributed to “human error” provides little information about why human performance routinely prevents adverse events. Hollnagel has proposed that things go right because people continuously adjust their work to match their operating conditions. These adjustments become increasingly important as systems continue to grow in complexity. Thus, the definition of safety should reflect not only “avoiding things that go wrong” but “ensuring that things go right.” The basis for safety management requires developing an understanding of everyday activities. However, few mechanisms to monitor everyday work exist in the aviation domain, which limits opportunities to learn how designs function in reality. This concept of safety thinking and safety management is reflected in the emerging field of resilience engineering. According to Hollnagel, a system is resilient if it can sustain required operations under expected and unexpected conditions by adjusting its functioning prior to, during, or following changes, disturbances, and opportunities. To explore “positive” behaviors that contribute to resilient performance in commercial aviation, the assessment team examined a range of existing sources of data about pilot and air traffic control (ATC) tower controller performance, including subjective interviews with domain experts and objective aircraft flight data records. These data were used to identify strategies that support resilient performance, methods for exploring and refining those strategies in existing data, and proposed methods for capturing and analyzing new data.

Null, Cynthia H.↗

Estimating Future Changes of Energy Demand for Heating and Cooling Buildings at NASA Centers GC23J-1198

With its unique and trusted earth observations, NASA is a critical source in informing decisions that will help achieve the U.S. goal of Net-Zero Greenhouse Gas (GHG) Emissions by 2050. NASA’s Prediction of Worldwide Energy Resource (POWER) project facilitates the use of NASA Earth Science data holdings within the energy, agricultural, and building heating/cooling design industries. POWER packages solar and meteorological data from several NASA projects in a user friendly GIS-enabled web services system (https://power.larc.nasa.gov). As part of the development of new data products to support the energy and building heating/cooling design communities, we estimate the changes in energy required to heat and cool buildings in the future climate at 14 different NASA site locations spread throughout the continental United States, as projected by CMIP6 climate models under different emissions scenarios. Bias-corrected downscaled time series of meteorological variables are taken from NASA Earth Exchange (NEX) Global Daily Downscaled Projections (GDDP-CMIP6) downscaled climate model data. The spread between the different model projections is accounted for by analyzing both the ensemble average of 22 CMIP6 models and 6 representative models with different climate sensitivities and different interannual variability. Changes in energy use are estimated in two ways. First, changes in the total annual heating and cooling degree days (HDD and CDD, respectively) are calculated relative to the current climate. This is done at all 14 sites. Second, the downscaled time series are used as inputs into RETScreen(R), a clean energy management decision tool, to give an estimate of heating/cooling energy use for a typical office building. We use this estimation method with model data at Langley Research Center. In the next 50 years, the annual total of HDD (CDD) is projected to decrease by 8-38% (increase by 5-28%) at all sites, with the increase in CDD typically a larger magnitude the decrease in HDD. For a typical small office building at Langley Research Center, the amount of energy needed to cool increases by 33-54% and the amount of energy to heat decreases by 29-40%. POWER is working to develop long term climate data services based on these results to include in future data products to provide to users.

Bradley M. Hegyi↗

Integrated Modeling Approach for the Terrestrial Planet Finder Mission

Because of the complexity of the Terrestrial Planet Finder (TPF) design concepts, the project will rely heavily on the use of engineering and science simulations to predict on-orbit performance. Furthermore, current understanding of these missions indicates that the 3m to 8m class optical systems need to be as stable as picometers in wavefront and sub-milli arcsec in pointing. These extremely small requirements impose on the models a level of predictive accuracy heretofore never achieved, especially in the area of microgravity effects, material property accuracy, thermal solution convergence, and all other second order modeling effects typically ignored. New modeling tools and analysis paradigms are developed which emphasize computational accuracy and fully integrated analytical simulations. The process is demonstrated on sample problems using the TPF Coronagraph design concept. The TPF project is also planning a suite of testbeds through which various aspects of the models and simulations will be verified.

terrestrial planet finder↗

T-38 Primary Flight Display Prototyping and HIVE Support Abstract & Summary

This fall I worked in EV3 within NASA's Johnson Space Center in The HIVE (Human Integrated Vehicles & Environments). The HIVE is responsible for human in the loop testing, getting new technologies in front of astronauts, operators, and users early in the development cycle to make the interfaces more human friendly. Some projects the HIVE is working on includes user interfaces for future spacecraft, wearables to alert astronauts about important information, and test beds to simulate mock missions. During my internship I created a prototype for T-38 aircraft displays using LabVIEW, learned how to use microcontrollers, and helped out with other small tasks in the HIVE. The purpose of developing a prototype for T-38 Displays in LabVIEW is to analyze functions of the display such as navigation in a cost and time effective manner. The LabVIEW prototypes allow Ellington Field AOD to easily make adjustments to the display before hardcoding the final product. LabVIEW was used to create a user interface for simulation almost identical to the real aircraft display. Goals to begin the T-38 PFD (Primary Flight Display) prototype included creating a T-38 PFD hardware display in a software environment, designing navigation for the menu's, incorporating vertical and horizontal navigation bars, and to add a heading bug for compass controls connected to the HSI (Horizontal Situation Indicator). To get started with the project, measurements of the entire display were taken. This enabled an accurate model of the hardware display to be created. Navigation of menu's required some exploration of different buttons on the display. The T-38 simulator and aircraft were used for examining the display. After one piece of the prototype was finished, another trip of to the simulator took place. This was done until all goals for the prototype were complete. Some possible integration ideas for displays in the near future are autopilot selection, touch screen displays, and crew member preferences. Complete navigation, control, and function customization will be achievable once a display is fully developed. Other than the T-38 prototyping, I spent time learning how to design small circuits and write code for them to function. This was done by adding electronic circuit components to breadboard and microcontroller then writing code to speak to those components through the microcontroller. I went through an Arduino starter kit to build circuits and code software that allowed the hardware to act. This work was planned to assist in a lighting project this fall but another solution was discovered for the lighting project. Other tasks that I assisted with, included hands on work such as mock-up construction/removal, logic analyzer repairs, and soldering with circuits. The unique opportunity to be involved work with NASA has significantly changed my educational and career goals. This opportunity has only opened the door to my career with engineering. I have learned over the span of this internship that I am fascinated by the type of work that NASA does. My desire to work in the aerospace industry has increased immensely. I hope to return to NASA to be more involved in the advancement of science, engineering, and spaceflight. My interests for my future education and career lie in NASA’s work - pioneering the future in space exploration, scientific discovery and aeronautics research.

Boniface, Andrew↗

System identification of the Large-Angle Magnetic Suspension Test Facility (LAMSTF)

The Large-Angle Magnetic Suspension Test Facility (LAMSTF), a laboratory-scale research project to demonstrate the magnetic suspension of objects over wide ranges of attitudes, has been developed. This system represents a scaled model of a planned Large-Gap Magnetic Suspension System (LGMSS). The LAMSTF system consists of a planar array of five copper electromagnets which actively suspend a small cylindrical permanent magnet. The cylinder is a rigid body and can be controlled to move in five independent degrees of freedom. Five position variables are sensed indirectly by using infra-red light-emitting diodes and light-receiving phototransistors. The motion of the suspended cylinder is in general nonlinear and hence only the linear, time-invariant perturbed motion about an equilibrium state is considered. One of the main challenges in this project is the control of the suspended element over a wide range of orientations. An accurate dynamic model plans an essential role in controller design. The analytical model of the LAMSTF system includes highly unstable real poles (about 10 Hz) and low-frequency flexible modes (about 0.16 Hz). Projection filters are proposed to identify the state space model from closed-loop test data in time domain. A canonical transformation matrix is also derived to transform the identified state space model into the physical coordinate. The LAMSTF system is stabilized by using a linear quadratic regulator (LQR) feedback controller. The rate information is obtained by calculating the back difference of the sensed position signals. The reference inputs contain five uncorrelated random signals. This control input and the system reponse are recorded as input/output data to identify the system directly from the projection filters. The sampling time is 4 ms and the model is fairly accurate in predicting the step responses for different controllers while the analytical model has a deficiency in the pitch axis.

Huang, Jen-Kuang↗

Infrared atlas charts of the eclipsed moon.

The objective of this atlas is to present the thermal response of the lunar surface observed during an eclipse of the moon with accurate position data. The observations were made at a wavelength of 11 microns with an angular resolution of 10 sec, equivalent to 17 km at the disk center. Over a thousand thermally anomalous regions (hot spots) were detected. They cool more slowly than their environs and remain warmer than their environs during the umbral phase. In addition to these very localized hot spots, some of the maria show thermal enhancements during the eclipse. Fourty four charts make up this atlas which are identical in coverage and projection to the Lunar Atlas Charts (LAC) series. The charts are in the form of digital images of a normalized temperature difference which is particularly useful for studying regions of small thermal enhancements. Each increase of intensity corresponds to a 4 K temperature increase.

Shorthill, R. W.↗

Mariner Mars 1971 photogrammetric calibrations.

One of the major objectives of the Mariner Mars 1971 mission was the systematic mapping of Mars. This required a complex and thorough photogrammetric calibration of both the wide-angle and narrow-angle cameras mounted on the spacecraft scan platform. Because of the peculiarities of the TV imaging techniques (transmission quality, low resolution, electronic distortion, etc.), combined with the extremely small vidicon format, many unique difficulties were encountered and many unprecedented problems had to be solved. Their successful solution, based on experience gained during the Surveyor and Mariner Mars 1969 projects, is discussed, and the calibration procedure for the parameters of interior orientation, as well as for opto-mechanical orthogonality, is described in detail.

Benesh, M.↗

Mariner 9 high-resolution albedo mapping of Mars

Large and small scale albedo markings obtained from Mariner 9 photographs and ground based telescope observations are shown on quadrangle charts with a scale of 1:5,000,000. Mercator and stereographic projections at the same scale are presented of the various regions of Mars along with explanatory information about their preparation. Changes in the albedo for the Solis Lacus area were observed and are compared with previous data for the same region. Large scale relief maps covering up to 1.7 million sq miles of the Martian surface are included.

Devaucouleurs, G.↗

Shuttle II - The next generation

A comparative evaluation is conducted for next-generation Space Shuttle-type system configurations, in light of mission and design goals, performance and operational requirements, and technology development needs and opportunities. Cargo vehicle options presently entertained are an unmanned Shuttle Derivative Vehicle and a Heavy Lift Launch Vehicle. Two high priority manned vehicle options are small (35,000-lb payload) and large (150,000-lb payload) fully reusable vehicles. Attention is given to single stage vs. two-stage 'Shuttle II' system performance and economic projections.

Eldred, C. H.↗

Optical properties of aggregate particles whose outer diameter is comparable to the wavelength

Results are described of numerical calculations of the optical properties (extinction efficiency, single-scattering albedo, phase function, and linear polarization) of aggregate particles whose outer diameter is comparable with the wavelength. Results are presented for two types of particle, one composed of monomers whose radius is small compared with the wavelength and a second containing monomers with larger radii. The shape of the forward-scattered lobe of the phase function is diagnostic of the mean projected area (but differs from that for an equal-area sphere), while the linear polarization, phase function at large scattering angles, and single-scattering albedo depend on the monomer diameter. The wavelength dependence of the extinction efficiency differs markedly from that for equal-area spheres. These results can be used to infer particle properties from remotely sensed data.

West, Robert A.↗

A conceptual design for the attitude control and determination system for the Magnetosphere Imager spacecraft

This paper presents a conceptual design for the attitude control and determination (ACAD) system for the Magnetosphere Imager (Ml) spacecraft. The MI is a small spin-stabilized spacecraft that has been proposed for launch on a Taurus-S expendable launch vehicle into a highly-ellipdcal polar Earth orbit. Presently, launch is projected for 1999. The paper describes the MI mission and ACAD requirements and then proposes an ACAD system for meeting these requirements. The proposed design is low-power, low-mass, very simple conceptually, highly passive, and consistent with the overall MI design philosophy, which is faster-better-cheaper. Still, the MI ACAD system is extremely robust and can handle a number of unexpected, adverse situations on orbit without impacting the mission as a whole. Simulation results are presented that support the soundness of the design approach.

Polites, M. E.↗

Quantifying Mapping Orbit Performance in the Vicinity of Primitive Bodies

Predicting and quantifying the capability of mapping orbits in the vicinity of primitive bodies is challenging given the complex orbit geometries that exist and the irregular shape of the bodies themselves. This paper employs various quantitative metrics to characterize the performance and relative effectiveness of various types of mapping orbits including terminator, quasi-terminator, hovering, pingpong, and conic-like trajectories. Metrics of interest include surface area coverage, lighting conditions, and the variety of viewing angles achieved. The metrics discussed in this investigation are intended to enable mission designers and project stakeholders to better characterize candidate mapping orbits during preliminary mission formulation activities.The goal of this investigation is to understand the trade space associated with carrying out remotesensing campaigns at small primitive bodies in the context of a robotic space mission. Specifically,this study seeks to understand the surface viewing geometries, ranges, etc. that are available fromseveral commonly proposed mapping orbits architectures.

Pavlak, Thomas A.↗

Elucidating Microbial Adaptation Dynamics via Autonomous Exposure and Sampling

The adaptation of micro-organisms to their environments is a complex process of interaction between the pressures of the environment and of competition. Reducing this multifactorial process to environmental exposure in the laboratory is a common tool for elucidating individual mechanisms of evolution, such as mutation rates. Although such studies inform fundamental questions about the way adaptation and even speciation occur, they are often limited by labor-intensive manual techniques. Current methods for controlled study of microbial adaptation limit the length of time, the depth of collected data, and the breadth of applied environmental conditions. Small idiosyncrasies in manual techniques can have large effects on outcomes; for example, there are significant variations in induced radiation resistances following similar repeated exposure protocols. We describe here a project under development to allow rapid cycling of multiple types of microbial environmental exposure. The system allows continuous autonomous monitoring and data collection of both single species and sampled communities, independently and concurrently providing multiple types of controlled environmental pressure (temperature, radiation, chemical presence or absence, and so on) to a microbial community in dynamic response to the ecosystem's current status. When combined with DNA sequencing and extraction, such a controlled environment can cast light on microbial functional development, population dynamics, inter- and intra-species competition, and microbe-environment interaction. The project's goal is to allow rapid, repeatable iteration of studies of both natural and artificial microbial adaptation. As an example, the same system can be used both to increase the pH of a wet soil aliquot over time while periodically sampling it for genetic activity analysis, or to repeatedly expose a culture of bacteria to the presence of a toxic metal, automatically adjusting the level of toxicity based on the number or growth rate of surviving cells. We are on our second prototype iteration, with demonstrated functions of microbial growth monitoring and dynamic exposure to UV-C radiation and temperature. We plan to add functionality for general chemical presence or absence by Nov. 2013. By making the project low-cost and open-source, we hope to encourage others to use it as a basis for future development of a common microbial environmental adaptation testbed.

Microbiology↗