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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.

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NASA NTRSDate not supplied

Wildfire monitoring using Unmanned Aerial Vehicles operating under UTM (STEReO)

STEReO (Scalable Traffic Management for Emergency Response Operations) project at NASA Ames is designed to provide UTM (UAS Traffic Management) services to unmanned aerial vehicles (UAVs) used for natural disaster response scenarios like wildfire and hurricanes. This will facilitate the use of unmanned aerial vehicles in regions where UAVs are currently prohibited to fly. In this paper we describe a complete architecture of using UAVs for wild fire monitoring in this STEReO environment. We simulate a complete fire monitoring scenario in an high fidelity simulation environment. The simulation consists of a fire drill in the vicinity of Redding airport, one of the test sites for CAL-FIRE. The autonomous vehicle connects to the STEReO systems and gathers information of other operation in the vicinity. The vehicle then uses on-board path planners and decision making algorithms for fire monitoring and mapping. In this paper the vehicle on-board architecture is described in details and the requirements to fly and interact with the STEReO system is discussed.

UAV UTM↗
NASA NTRS2007

Integrated Clinical Training for Space Flight Using a High-Fidelity Patient Simulator in a Simulated Microgravity Environment

This viewgraph presentation reviews the use of telemedicine in a simulated microgravity environment using a patient simulator. For decades, telemedicine techniques have been used in terrestrial environments by many cohorts with varied clinical experience. The success of these techniques has been recently expanded to include microgravity environments aboard the International Space Station (ISS). In order to investigate how an astronaut crew medical officer will execute medical tasks in a microgravity environment, while being remotely guided by a flight surgeon, the Medical Operation Support Team (MOST) used the simulated microgravity environment provided aboard DC-9 aircraft teams of crew medical officers, and remote flight surgeons performed several tasks on a patient simulator.

Hurst, Victor↗
NASA NTRS1994

Thermoacoustic environments to simulate reentry conditions

Aerothermal environments as encountered during the reentry of spaceplanes or during the cruise of hypersonic aircrafts represent complex loading conditions for the external structures of those vehicles. In order to shield against the aerodynamic heating a special Thermal Protection System (TPS) is required which is designed as a light weight structure to reduce the weight penalty. TPS is therefore vulnerable to vibroacoustic fatigue caused by the pressure fluctuations of the environment. Because of the complex interactions between the loading forces and the resulting structural response which make an analytical treatment difficult and in order to provide means for fatigue testing IABG has designed and built a thermoacoustic facility which recently became operational. The facility is capable to produce surface temperatures up to 1.300 C at sound pressure levels up to 160 dB. This paper describes the design of the facility, some operational test work it also deals with problems associated with the facility instrumentation.

Bayerdoerfer, Gerhard↗
NASA NTRS2005

VERSE - Virtual Equivalent Real-time Simulation

Distributed real-time simulations provide important timing validation and hardware in the- loop results for the spacecraft flight software development cycle. Occasionally, the need for higher fidelity modeling and more comprehensive debugging capabilities - combined with a limited amount of computational resources - calls for a non real-time simulation environment that mimics the real-time environment. By creating a non real-time environment that accommodates simulations and flight software designed for a multi-CPU real-time system, we can save development time, cut mission costs, and reduce the likelihood of errors. This paper presents such a solution: Virtual Equivalent Real-time Simulation Environment (VERSE). VERSE turns the real-time operating system RTAI (Real-time Application Interface) into an event driven simulator that runs in virtual real time. Designed to keep the original RTAI architecture as intact as possible, and therefore inheriting RTAI's many capabilities, VERSE was implemented with remarkably little change to the RTAI source code. This small footprint together with use of the same API allows users to easily run the same application in both real-time and virtual time environments. VERSE has been used to build a workstation testbed for NASA's Space Interferometry Mission (SIM PlanetQuest) instrument flight software. With its flexible simulation controls and inexpensive setup and replication costs, VERSE will become an invaluable tool in future mission development.

virtual real time↗
NASA NTRS2005

Simulation of Range Safety for the NASA Space Shuttle

This paper describes a simulation environment that seamlessly combines a number of safety and environmental models for the launch phase of a NASA Space Shuttle mission. The components of this simulation environment represent the different systems that must interact in order to determine the Expectation of casualties (E(sub c)) resulting from the toxic effects of the gas dispersion that occurs after a disaster affecting a Space Shuttle within 120 seconds of lift-off. The utilization of the Space Shuttle reliability models, trajectory models, weather dissemination systems, population models, amount and type of toxicants, gas dispersion models, human response functions to toxicants, and a geographical information system are all integrated to create this environment. This simulation environment can help safety managers estimate the population at risk in order to plan evacuation, make sheltering decisions, determine the resources required to provide aid and comfort, and mitigate damages in case of a disaster. This simulation environment may also be modified and used for the landing phase of a space vehicle but will not be discussed in this paper.

Rabelo, Luis↗
NASA NTRS1974

Hypobaric chamber for the study of oral health problems in a simulated spacecraft environment

A hypobaric chamber was constructed to house two marmo-sets simultaneously in a space-simulated environment for periods of 14, 28 and 56 days which coincided with the anticipated Skylab missions. This report details the fabrication, operation, and performance of the chamber and very briefly reviews the scientific data from nine chamber trials involving 18 animals. The possible application of this model system to studies unrelated to oral health or space missions is discussed.

Brown, L. R.↗
NASA NTRS1986

Ground testing in a simulated auroral environment

Shuttle polar orbit missions are being planned in which astronaut extravehicular activities (EVA) will eventually include external operations or repair and refurbishment of satellites. Recent satellite data and model calculations show that significant spacecraft charging and differential charging occurs in that environment and could endanger equipment and personnel involved in the EVA. These spacecraft charging events take place in response to an intense flux of high energy electrons accompanied by a large drop in the ambient plasma density. The extent of which the auroral environment can be simulated in a large vacuum chamber are determined so that conditions which lead to significant charging and discharging may be observed and controlled. A large chamber would be required in order to simulate the effects of an aurora-like, large cross-section, energetic electron precipitation on a target system the size of an astronaut with a life support system. The precipitating electrons can be simulated with an array of multipactor sources and the background ionization produced by the beam can be limited to the range of the auroral density if the chamber pressure is not significantly above 1 x .000001 Torr. Some small chamber work has shown that the plasma in the beam will diffuse radially at a rate determined by the Bohm diffusion coefficient.

Mcintyre, Bernard↗
NASA NTRS1990

A study of murine bone marrow cells cultured in bioreactors which create an environment which simulated microgravity

Previous research indicated that mouse bone marrow cells could be grown in conditions of simulated microgravity. This environment was created in rotating bioreactor vessels. On three attempts mouse cells were grown successfully in the vessels. The cells reached a stage where the concentrations were doubling daily. Phenotypic analysis using a panel of monoclonal antibodies indicated that the cell were hematopoietic pluripotent stem cells. One unsuccessful attempt was made to reestablish the immune system in immunocompromised mice using these cells. Since last summer, several unsuccessful attempts were made to duplicate these results. It was determined by electron microscopy that the cells successfully grown in 1989 contained virus particles. It was suggested that these virally parasitized cells had been immortalized. The work of this summer is a continuation of efforts to grow mouse bone marrow in these vessels. A number of variations of the protocol were introduced. Certified pathogen free mice were used in the repeat experiments. In some attempts the medium of last summer was used; in others Dexture Culture Medium containing Iscove's Medium supplemented with 20 percent horse serum and 10-6 M hydrocortisone. Efforts this summer were directed solely to repeating the work of last summer. Plans were made for investigations if stem cells were isolated. Immortalization of the undifferentiated stem cell would be attempted by transfection with an oncogenic vector. Selective differentiation would be induced in the stem cell line by growing it with known growth factors and immune response modulators. Interest is in identifying any surface antigens unique to stem cells that would help in their characterization. Another goal was to search for markers on stem cells that would distinguish them from stem cells committed to a particular lineage. If the undifferentiated hematopoietic stem cell was obtained, the pathways that would terminally convert it to myeloid, lyphoid, erythroid, or other cell lines would be studied. Transfection with a known gene would be attempted and then conversion to a terminally identifiable cell.

Lawless, Brother Desales↗
NASA NTRS1972

Control of an artificial infrared environment to simulate complex, time varying orbital conditions

A computer-controlled infrared simulation system has recently been developed for thermal vacuum ground testing of spacecraft in the Space Environment Simulation Laboratory of the NASA Manned Spacecraft Center. The system can simultaneously follow as many as 30 separate time-varying intensity profiles for irradiation of different areas of a test spacecraft, producing an environment that more closely resembles the changing conditions experienced by an orbiting spacecraft. A description of the hardware is included, but emphasis is placed upon computer techniques that have been developed to maximize the capabilities of the control system within the constraints imposed by a limited computer capability. Among the topics discussed are open-loop control, closed-loop control, manual alteration of profiles, compensation for slow response of the radiation source, and compensation for interacting control zones. Examples of typical results obtained using the control system are also presented.

Dewey, R. L.↗
NASA NTRS2003

Evaluation of Ceramic Foams and Simulated Reentry Environments

NASA and Ames is conducting ongoing research in lower density reusable TPS material for future reentry vehicles. Ceramic foams from pre ceramic polymer routes have potential for use in both acreage TPS and as tile leading edges for reentry vehicles. One of the key factors to investigate, when developing new materials for reentry applications, is their oxidation behavior in the appropriate reentry environment whrch can be simulated using ground based arc jet (plasma jet) testing. Studies have shown that oxidation rates of materials will differ when exposed to either monatomatic or molecular oxygen and the amount of monoatomic oxygen depends on the conditions particular to a given test situation. Monoatomic oxygen is always present in reentry environment, therefore arc jet testing is required to provide the appropriate conditions (stagnation pressures, heat fluxes, enthalpies, heat loads and atmospheres) encountered during flight. This preliminary work looks at the response of ceramic foams (Si systems) exposed to simulated reentry environments and investigates the influence of microstructure and composition on the materials response.

Stackpoole, Mairead↗
NASA NTRS2018

Sixty Earth-Days Test of a Prototype Pt/HTCC Alumina Package in Simulated Venus Environment

This paper presents experimental results of a prototype high temperature co-fired ceramic (HTCC) package with Au/Pt metallization in a three-phase harsh environment test that culminated with 60-day demonstration in simulated Venus surface environment of 465 degC with corrosive atmosphere at 90 bar pressure. The prototype package is based on previously developed and reported HTCC package successfully tested with multiple analog and digital silicon carbide (SiC) high temperatures semiconductor integrated circuits (ICs) at NASA Glenn Research Center in 500 degC Earth air ambient for over ten thousands hours, and short-term tested at temperatures above 800 degC. The three-phase harsh environment test started with 48 hours in 465 degC Earth air, followed by 48 hours in 465 degC nitrogen at 90 bar pressure and 1400 hours in simulated Venus surface environment of 465 degC with corrosive atmosphere at 90 bar. Initial analytical results of the package materials and surfaces after exposure to Venus environment are discussed to assess the stability of the packaging materials in the tested environments. The test in simulated Venus environment was implemented in the NASA Glenn Extreme Environment Rig (GEER). The results of this study suggest that an effective encapsulation of areas of surface metallization and vicinities may help to improve electrical performance of a HTCC alumina packaging system in Venus environment.

Chen, Liangyu↗
NASA NTRS2018

Sixty Earth-Days Test of a Prototype Pt/HTCC Alumina Package in Simulated Venus Environment

This paper presents experimental results of a prototype high temperature co-fired ceramic (HTCC) package with Au/Pt metallization in a three-phase harsh environment test that culminated with 60-day demonstration in simulated Venus surface environment of 465 degrees Centigrade with corrosive atmosphere at 90 bars pressure. The prototype package is based on a previously developed and reported HTCC package successfully tested with multiple analog and digital silicon carbide (SiC) high temperatures semiconductor integrated circuits (ICs) at NASA Glenn Research Center in 500 degrees Centigrade Earth air ambient for over ten thousand hours, and short-term tested at temperatures above 800 degrees Centigrade. The three-phase harsh environment test started with 48 hours in 465 degrees Centigrade Earth air, followed by 48 hours in 465 degrees Centigrade nitrogen at 90-bar pressure and 1400 hours in simulated Venus surface environment of 465 degrees Centigrade with corrosive atmosphere at 90 bars. Initial analytical results of the package materials and surfaces after exposure to the Venus environment are discussed to assess the stability of the packaging materials in the tested environments. The test in a simulated Venus environment was implemented in the NASA Glenn Extreme Environment Rig (GEER). The results of this study suggest that an effective encapsulation of areas of surface metallization and vicinities may help to improve electrical performance of a HTCC alumina packaging system in Venus environment.

Chen, Liang-Yu↗