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NASA Technical Reports Server (NTRS) (676,011 recursos)
The NTRS is a valuable resource for students, educators, researchers, and the public for access to NASA's current and historical technical literature since it was first released in 1994. NTRS provides access to approximately 500K aerospace related citations, 90K full-text online documents, and 111K images and videos. NTRS numbers continues to grow over time as new scientific and technical information (STI) is created or funded by NASA. The type of information found in NTRS include: conference papers, images, journal articles, photos, meeting papers, movies, patents, research reports, and technical videos.

NASA Center for AeroSpace Information (CASI) (513,494) NIX Images (81,938)


Mostrando recursos 1 - 20 de 310,850

1. Microorganism Utilization for Synthetic Milk Production - Morford, Megan A.; Caro, Janicce; Hummerick, Mary; Richards, Jeffrey T.; Wheeler, Raymond M.; Strayer, Richard F.; Khodadad, Christina Louise; Spencer, LaShelle E.; Birmele, Michele N.
A desired architecture for long duration spaceflight, such as aboard the International Space Station (ISS) or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of this project was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel- through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and...

2. Microorganism Utilization for Synthetic Milk Production - Mccoy, LaShelle E.; Strayer, Richard F.; Caro, Janicce L.; Wheeler, Raymond M.; Birmele, Michele N.; Morford, Megan A.; Richards, Jeffrey T.; Khodadad, Christina L.; Hummerick, Mary E.
A desired architecture for long duration spaceflight, such as aboard the International Space Station (ISS) or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of this project was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel- through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and...

3. Towards Real-time, On-board, Hardware-Supported Sensor and Software Health Management for Unmanned Aerial Systems - Reinbacher, Thomas; Rozier, Kristin Y.; Schumann, Johann; Mbaya, Timmy; Mengshoel, Ole J.; Ippolito, Corey
Unmanned aerial systems (UASs) can only be deployed if they can effectively complete their missions and respond to failures and uncertain environmental conditions while maintaining safety with respect to other aircraft as well as humans and property on the ground. In this paper, we design a real-time, on-board system health management (SHM) capability to continuously monitor sensors, software, and hardware components for detection and diagnosis of failures and violations of safety or performance rules during the flight of a UAS. Our approach to SHM is three-pronged, providing: (1) real-time monitoring of sensor and/or software signals; (2) signal analysis, preprocessing, and...

4. Computational Fluid Dynamics Uncertainty Analysis for Payload Fairing Spacecraft Environmental Control Systems - Ilie, Marcel; Groves, Curtis; Schallhorn, Paul
Spacecraft components may be damaged due to airflow produced by Environmental Control Systems (ECS). There are uncertainties and errors associated with using Computational Fluid Dynamics (CFD) to predict the flow field around a spacecraft from the ECS System. This paper describes an approach to estimate the uncertainty in using CFD to predict the airflow speeds around an encapsulated spacecraft.

5. International Human Spaceflight Program Update - USA - Fincke, E. Michael
No abstract available

6. Ecological Impacts of the Space Shuttle Program at John F. Kennedy Space Center, Florida - Holloway-Adkins, Karen G.; Hall, Carlton R.; Provancha, Jane A.; Foster, Tammy E.; Stolen, Eric D.; Cancro, Naresa R.; Drese, John H.; Breininger, David R.; Scheidt, Doug A.; Lowers, Russ H.; Reyier, Eric A.; Schmalzer, Paul A.; Oddy, Donna M.; Duncan, Brean W.
The Space Shuttle Program was one of NASAs first major undertakings to fall under the environmental impact analysis and documentation requirements of the National Environmental Policy Act of 1969 (NEPA). Space Shuttle Program activities at John F. Kennedy Space Center (KSC) and the associated Merritt Island National Wildlife Refuge (MINWR) contributed directly and indirectly to both negative and positive ecological trends in the region through the long-term, stable expenditure of resources over the 40 year program life cycle. These expenditures provided support to regional growth and development in conjunction with other sources that altered land use patterns, eliminated and modified...

7. The Fleet Application for Scheduling and Tracking (FAST) Management Website - Marrero-Perez, Radames J.
The FAST application was designed to replace the paper and pen method of checking out and checking in GSA Vehicles at KSC. By innovating from a paper and pen based checkout system to a fully digital one, not only the resources wasted by printing the checkout forms have been reduced, but it also reduces significantly the time that users and fleet managers need to interact with the system as well as improving the record accuracy for each vehicle. The vehicle information is pulled from a centralized database server in the SPSDL. In an attempt to add a new feature to...

8. Supporting Multiple Programs and Projects at NASA's Kennedy Space Center - Stewart, Camiren L.
With the conclusion of the shuttle program in 2011, the National Aeronautics and Space Administration (NASA) had found itself at a crossroads for finding transportation of United States astronauts and experiments to space. The agency would eventually hand off the taxiing of American astronauts to the International Space Station (ISS) that orbits in Low Earth Orbit (LEO) about 210 miles above the earth under the requirements of the Commercial Crew Program (CCP). By privatizing the round trip journey from Earth to the ISS, the space agency has been given the additional time to focus funding and resources to projects that...

9. BRIC-21: Global Transcriptome Profiling to Identify Cellular Stress Mechanisms Responsible for Spaceflight-Induced Antibiotic Resistance - Fajardo-Cavazos, Patricia; Nicholson, Wayne L.
Comparisons of spaceflight stress responses in Bacillus subtilis spores and Staphylococcus epidermidis cells to ground-based controls will be conducted to uncover alterations in their antibiotic susceptibility.

10. Multi-Tone Millimeter-Wave Frequency Synthesizer for Atmospheric Propagation Studies - Simons, Rainee N.; Wintucky, Edwin G.
This paper presents the design and test results of a multi-tone millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator. The intended application of the synthesizer is in a space-borne transmitter for radio wave atmospheric studies at Q-band (37-43 GHz). These studies would enable the design of robust high data rate space-to-ground satellite communication links.

11. Turbulence Model Effects on RANS Simulations of the HIFiRE Flight 2 Ground Test Configurations - Vyas, Manan A.; Mankbadi, Mina R.; Georgiadis, Nicholas J.
The Wind-US Reynolds-averaged Navier-Stokes solver was applied to the Hypersonic International Flight Research Experimentation (HIFiRE) Flight 2 scramjet ground test configuration. Two test points corresponding to flight Mach numbers of 5.9 and 8.9 were examined. The emphasis was examining turbulence model effects on the prediction of flow path pressures. Three variants of the Menter k-omega turbulence model family were investigated. These include the baseline (BSL) and shear stress transport (SST) as well as a modified SST model where the shear stress limiter was altered. Variations in the turbulent Schmidt number were also considered. Choice of turbulence model had a substantial...

12. Navigation Performance of Global Navigation Satellite Systems in the Space Service Volume - Force, Dale A.
This paper extends the results I reported at this year's ION International Technical Meeting on multi-constellation GNSS coverage by showing how the use of multi-constellation GNSS improves Geometric Dilution of Precision (GDOP). Originally developed to provide position, navigation, and timing for terrestrial users, GPS has found increasing use for in space for precision orbit determination, precise time synchronization, real-time spacecraft navigation, and three-axis attitude control of Earth orbiting satellites. With additional Global Navigation Satellite Systems (GNSS) coming into service (GLONASS, Galileo, and Beidou) and the development of Satellite Based Augmentation Services, it is possible to obtain improved precision by using...

13. Navigation Performance of Global Navigation Satellite Systems in the Space Service Volume - Force, Dale A.
GPS has been used for spacecraft navigation for many years center dot In support of this, the US has committed that future GPS satellites will continue to provide signals in the Space Service Volume center dot NASA is working with international agencies to obtain similar commitments from other providers center dot In support of this effort, I simulated multi-constellation navigation in the Space Service Volume In this presentation, I extend the work to examine the navigational benefits and drawbacks of the new constellations center dot A major benefit is the reduced geometric dilution of precision (GDOP). I show that there...

14. A Method for Estimating the Probability of Floating Gate Prompt Charge Loss in a Radiation Environment - Edmonds, L. D.
Because advancing technology has been producing smaller structures in electronic circuits, the floating gates in modern flash memories are becoming susceptible to prompt charge loss from ionizing radiation environments found in space. A method for estimating the risk of a charge-loss event is given.

15. Estimating How Often Mass Extinctions Due to Impacts Occur on the Earth - Buratti, Bonnie J.
This hands-on, inquiry based activity has been taught at JPL's summer workshop "Teachers Touch the Sky" for the past two decades. Students act as mini-investigators as they gather and analyze data to estimate how often an impact large enough to cause a mass extinction occurs on the Earth. Large craters are counted on the Moon, and this number is extrapolated to the size of the Earth. Given the age of the Solar System, the students can then estimate how often large impacts occur on the Earth. This activity is based on an idea by Dr. David Morrison, NASA Ames Research...

16. A Compact Two-Stage 120 W GaN High Power Amplifier for SweepSAR Radar Systems - Price, Douglas; Veilleux, Louise; Hoffman, James; Thrivikraman, Tushar; Horst, Stephen
This work presents the design and measured results of a fully integrated switched power two-stage GaN HEMT high-power amplifier (HPA) achieving 60% power-added efficiency at over 120Woutput power. This high-efficiency GaN HEMT HPA is an enabling technology for L-band SweepSAR interferometric instruments that enable frequent repeat intervals and high-resolution imagery. The L-band HPA was designed using space-qualified state-of-the-art GaN HEMT technology. The amplifier exhibits over 34 dB of power gain at 51 dBm of output power across an 80 MHz bandwidth. The HPA is divided into two stages, an 8 W driver stage and 120 W output stage. The amplifier...

17. Shape Memory Alloy (SMA)-Based Launch Lock - Bar-Cohen, Yoseph; Badescu, Mircea; Bao, Xiaoqi
Most NASA missions require the use of a launch lock for securing moving components during the launch or securing the payload before release. A launch lock is a device used to prevent unwanted motion and secure the controlled components. The current launch locks are based on pyrotechnic, electro mechanically or NiTi driven pin pullers and they are mostly one time use mechanisms that are usually bulky and involve a relatively high mass. Generally, the use of piezoelectric actuation provides high precession nanometer accuracy but it relies on friction to generate displacement. During launch, the generated vibrations can release the normal...

18. Miniature Cryogenic Valves for a Titan Lake Sampling System - Takano, Nobuyuki; Avellar, Louisa; Zimmerman, Wayne; Sherrit, Stewart
The Cassini mission has revealed Titan to be one of the most Earthlike worlds in the Solar System complete with many of the same surface features including lakes, river channels, basins, and dunes. But unlike Earth, the materials and fluids on Titan are composed of cryogenic organic compounds with lakes of liquid methane and ethane. One of the potential mission concepts to explore Titan is to land a floating platform on one of the Titan Lakes and determine the local lake chemistry. In order to accomplish this within the expected mass volume and power budgets there is a need to...

19. Flow Energy Piezoelectric Bimorph Nozzle Harvester - Lee, Hyeong Jae; Sherrit, Stewart; Tosi, Luis Phillipe; Walkemeyer, Phillip; Hall, Jeffery L.; Corbett, Gary; Kim, Namhyo; Hasenoehrl, Jennifer; Sun, Kai; Colonius, Tim; Arrazola, Alvaro
There is a need for a long-life power generation scheme that could be used downhole in an oil well to produce 1 Watt average power. There are a variety of existing or proposed energy harvesting schemes that could be used in this environment but each of these has its own limitations. The vibrating piezoelectric structure is in principle capable of operating for very long lifetimes (decades) thereby possibly overcoming a principle limitation of existing technology based on rotating turbo-machinery. In order to determine the feasibility of using piezoelectrics to produce suitable flow energy harvesting, we surveyed experimentally a variety of...

20. Impact of Acoustic Standing Waves on Structural Responses - Kolaini, Ali R.
For several decades large reverberant chambers and most recently direct field acoustic testing have been used in the aerospace industry to test larger structures with low surface densities such as solar arrays and reflectors to qualify them and to detect faults in the design and fabrication. It has been reported that in reverberant chamber and direct acoustic testing, standing acoustic modes may strongly couple with the fundamental structural modes of the test hardware (Reference 1). In this paper results from a recent reverberant chamber acoustic test of a composite reflector are discussed. These results provide further convincing evidence of the...

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