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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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At least 523 records · Page 29
All sourcesNASA NTRSDOE OSTI
NASA NTRS1996

Ultra Small Aperture Terminal: System Design and Test Results

The Ultra Small Aperture Terminal (USAT) has been developed to test and demonstrate remote and broadcast satcom applications via the Advanced Communications Technology Satellite (ACTS). The design of these ground stations emphasize small size, low power consumption, portable and rugged terminals. Each ground station includes several custom design parts such as 35 cm diameter antenna, 1/4 Watt transmitter with built-in upconverter, and 4.0 dB Noise Figure (NF) receiver with built-in downconverter. In addition, state-of-the-art commercial parts such as highly stable ovenized crystal oscillators and dielectric resonator oscillators are used in the ground station design. Presented in this paper are system level design description, performance, and sample applications.

Sohn, Philip Y.↗
NASA NTRS1997

Low Cost Large Space Antennas

The mobile communication community could significantly benefit from the availability of low-cost, large space-deployable antennas. A new class of space structures, called inflatable deployable structures, will become an option for this industry in the near future. This new technology recently made significant progress with respect to reducing the risk of flying large inflatable structures in space. This progress can be attributed to the successful space flight of the Inflatable Antenna Experiment in May of 1996, which prompted the initiation of the NASA portion of the joint NASA/DOD coordinated Space Inflatables Program, which will develop the technology to be used in future mobile communications antennas along with other users. The NASA/DOD coordinated Space Inflatables Program was initiated in 1997 as a direct result of the Inflatable Antenna Experiment. The program adds a new NASA initiative to a substantial DOD program that involves developing a series of ground test hardware, starting with 3 meter diameter units and advancing the manufacturing techniques to fabricate a 25 meter ground demonstrator unit with surface accuracy exceeding the requirements for mobile communication applications. Simultaneously, the program will be advancing the state of the art in several important inflatable technology areas, such as developing rigidizable materials for struts and tori and investigating thin film technology issues, such as application of coatings, property measurement and materials processing and assembly techniques. A very important technology area being addressed by the program is deployment control techniques. The program will sponsor activities that will lead to understanding the effects of material strain energy release, residual air in the stowed structure, and the design of the launch restraint and release system needed to control deployment dynamics. Other technology areas directly applicable to developing inflatable mobile communication antennas in the near future are analytical performance prediction tools, configuration studies and miniaturizing the inflation systems.

Chmielewski, Artur B.↗
NASA NTRS2003

Recent Accomplishments in Laser-Photovoltaic Wireless Power Transmission

Wireless power transmission can be accomplished over long distances using laser power sources and photovoltaic receivers. Recent research at AMOS has improved our understanding of the use of this technology for practical applications. Research by NASA, Boeing, the University of Alabama-Huntsville, the University of Colorado, Harvey Mudd College, and the Naval Postgraduate School has tested various commercial lasers and photovoltaic receiver configurations. Lasers used in testing have included gaseous argon and krypton, solid-state diodes, and fiber optic sources, at wavelengths ranging from the visible to the near infra-red. A variety of Silicon and Gallium Arsenide photovoltaic have been tested with these sources. Safe operating procedures have been established, and initial tests have been conducted in the open air at AMOS facilities. This research is progressing toward longer distance ground demonstrations of the technology and practical near-term space demonstrations.

Fikes, John C.↗
NASA NTRS2010

The History and Promise of Combined Cycle Engines for Access to Space Applications

For the summer of 2010, I have been working in the Aerodynamics and Propulsion Branch at NASA Dryden Flight Research Center studying combined-cycle engines, a high speed propulsion concept. Combined cycle engines integrate multiple propulsion systems into a single engine capable of running in multiple modes. These different modes allow the engine to be extremely versatile and efficient in varied flight conditions. The two most common types of combined cycle engines are Rocket-Based Combined Cycle (RBCC) and Turbine Based Combined Cycle (TBCC). The RBCC essentially combines a rocket and ramjet engine, while the TBCC integrates a turbojet and ramjet1. These two engines are able to switch between different propulsion modes to achieve maximum performance. Extensive conceptual and ground test studies of RBCC engines have been undertaken; however, an RBCC engine has never, to my knowledge, been demonstrated in flight. RBCC engines are of particular interest because they could potentially power a reusable launch vehicle (RLV) into space. The TBCC has been flight tested and shown to be effective at reaching supersonic speeds, most notably in the SR-71 Blackbird2.

Clark, Casie↗
NASA NTRS2019

Progress Towards Modeling the Mars Science Laboratory PICA-NuSil Heatshield

The data collected by the Mars Science Laboratory (MSL) Entry, Descent and Landing Instrumentation, MEDLI, have become an established reference to assess the performance of engineering models of the Phenolic Impregnated Carbon Ablator (PICA) and to validate hypersonic computational fluid dynamics (CFD) tools for entry systems. MEDLI measurements are also extensively used as validation reference for current developments of high-fidelity material response models for PICA. So large has been the scientific output and impact of MEDLI that a follow-up instrumentation suite MEDLI2 is underway for the upcoming Mars 2020 mission.A feature neglected thus far in the modeling of the MSL heatshield, is the presence of a silicone-based room temperature vulcanizing coating designated NuSil CV-1144-0. NuSil was used to coat the entire MSL heatshield, including the MEDLI plugs, to mitigate the spread of phenolic dust from PICA, and limit contamination during clean room operations. NuSil CV-1144-0 is a space grade siloxane copolymer, designed as an oxygen protection barrier for extreme low temperature environment.Assessments conducted during MSL development demonstrated that the presence of NuSil had no adverse effect on the performance of PICA. However, evidence from ground testing of PICA-NuSil (PICA-N) models in the HyMETS arc-jet test facility suggests that the silicone changes the high temperature response of PICA. It is therefore critical to assess the importance of modeling the coating in ongoing code validation efforts.

Bessire, Brody K.↗
NASA NTRS2019

IMERG V06: Changes to the Morphing Algorithm

As the US Science Team’s globally gridded precipitation product from the NASA/JAXA Global Precipitation Measurement (GPM) mission, the Integrated Multi-satellitE Retrievals for GPM (IMERG) estimates the surface precipitation rates at 0.1° every half-hour using spaceborne sensors for various scientific and societal applications. One key component of IMERG is the morphing algorithm, which uses motion vectors to perform quasi-Lagrangian interpolation to fill in gaps in the passive microwave precipitation field using motion vectors. Up to IMERG V05, the motion vectors were derived from the large-scale motions of infrared observations of cloud tops. This study details the changes introduced in IMERG V06 to derive motion vectors from large-scale motions of selected atmospheric variables in numerical models, which allow IMERG estimates to be extended from the 60°N/S latitude band to the entire globe. Evaluation against both instantaneous passive microwave retrievals and ground measurements demonstrates the general improvement in the precipitation field of the new approach. Most of the model variables tested exhibited similar performance, but total precipitable water vapor was chosen as the source of the motion vectors for IMERG V06 due to its competitive performance and global completeness. Continuing assessments will provide further insights into possible refinements of this revised morphing scheme in future versions of IMERG.

Jackson Tan↗
NASA NTRSDate not supplied

Uncertainty Estimates for Sonic-Boom Pressure Signatures and Loudness Carpets

A non-intrusive uncertainty quantification method is applied to computational analysis of supersonic, low-boom aircraft. The mean and standard deviation statistics of the pressure waveforms and loudness metrics are evaluated through use of numerical quadrature. The probability density function (p.d.f.) of these outputs is evaluated via kernel density estimation. The simulations use an inviscid, embedded-boundary Cartesian-mesh flow solver in the nearfield combined with an augmented Burgers’ equation solver for propagation in the farfield. The results show that the p.d.f. of the waveform is bimodal at shocks, which makes the mean and standard deviation statistics inappropriate. Despite this limitation, we show that the moment statistics can provide effective assessment of discrepancies when comparing with experimental data. This is demonstrated by presenting uncertainty analysis of a wind-tunnel test and showing that we significantly improve the predictions when we include the test uncertainties in the simulation. Normal distributions are obtained for the ground signature and loudness metrics, which is primarily due to the careful shaping of the low-boom waveform. Separation of variables and error control are used to reduce computational cost. We demonstrate that this is an efficient approach in the sense of balancing numerical errors in the statistics quadrature with discretization errors in the solvers.

ARMD↗
NASA NTRS1993

The Coherent Launchsite Wind Sounder (CLAWS)

This talk will provide a description of the Coherent Launchsite Wind Sounder (CLAWS) program for the development of a near real-time launchsite wind measurement system. The CLAWS program was motivated by the need to have wind measurements for spacecraft launch systems that are more timely than those from balloons. and that measure the winds along the booster's flight path. This program went from conceptual development to the testing of a breadboard system at KSC in concert with the launch of STS-48 in September of 1991. The system demonstrated the capability to measure the wind field, that a launch vehicle will traverse, from ground level to an altitude of 26 Km in approximately six minutes. The presentation will cover the concept, the hardware and the algorithms required, the test program and some results from the CLAWS system.

Price, Douglas B.↗
NASA NTRS1992

Investigation of advanced propulsion technologies: The RAM accelerator and the flowing gas radiation heater

The two principal areas of advanced propulsion investigated are the ram accelerator and the flowing gas radiation heater. The concept of the ram accelerator is presented as a hypervelocity launcher for large-scale aeroballistic range applications in hypersonics and aerothermodynamics research. The ram accelerator is an in-bore ramjet device in which a projectile shaped like the centerbody of a supersonic ramjet is propelled in a stationary tube filled with a tailored combustible gas mixture. Combustion on and behind the projectile generates thrust which accelerates it to very high velocities. The acceleration can be tailored for the 'soft launch' of instrumented models. The distinctive reacting flow phenomena that have been observed in the ram accelerator are relevant to the aerothermodynamic processes in airbreathing hypersonic propulsion systems and are useful for validating sophisticated CFD codes. The recently demonstrated scalability of the device and the ability to control the rate of acceleration offer unique opportunities for the use of the ram accelerator as a large-scale hypersonic ground test facility. The flowing gas radiation receiver is a novel concept for using solar energy to heat a working fluid for space power or propulsion. Focused solar radiation is absorbed directly in a working gas, rather than by heat transfer through a solid surface. Previous theoretical analysis had demonstrated that radiation trapping reduces energy loss compared to that of blackbody receivers, and enables higher efficiencies and higher peak temperatures. An experiment was carried out to measure the temperature profile of an infrared-active gas and demonstrate the effect of radiation trapping. The success of this effort validates analytical models of heat transfer in this receiver, and confirms the potential of this approach for achieving high efficiency space power and propulsion.

Bruckner, A. P.↗
NASA NTRS2011

Cryogenic Thermal Vacuum Testing with Remote Optical Metrology

Flexure Engineering was awarded an SBIR to research and develop technology needed to build a thermal vacuum chamber made to take laser radar metrology through a window. The XATF test is proof of concept for this, and demonstrated the need for such a chamber. XATF refers to two pieces of critical ground support equipment for NASA's JWST (James Webb Space Telescope) Integrated Science Instrument Module (ISIM), the ISIM Alignment Target Fixture (IATF) and the Master Alignment Target Fixture (MATF). These optical alignment assemblies require characterization while under cryogenic temperature. A thermal vacuum chamber equipped with a shroud cooled with gaseous and liquid nitrogen was used. An inner shroud was cooled with liquid helium to approximately 30K. The XATF assemblies were kinematically mounted and oriented inside the inner shroud such that the optical targets were visible from outside an optical window on one of the chamber ports. Laser radar and theodolite mounted outside the window took measurements of various optical targets. Two cold cycles were completed. A third cycle was aborted. Metrology was successfully taken. There were some problems with the helium system. The cryo pumps were turned off to reduce vibrations during metrology. Many new technologies and testing methods must be developed for JWST and future programs that will require precision measurements. These technologies will be applicable to other cold temperature applications, such as lunar missions and superconductors. Remote metrology technologies can also be applicable to testing in harsh environments. Facilities with remote metrology capability will be valuable.

Boyd, Guinevere↗
NASA NTRS2014

Creating a Test Validated Structural Dynamic Finite Element Model of the Multi-Utility Technology Test Bed Aircraft

Small modeling errors in the finite element model will eventually induce errors in the structural flexibility and mass, thus propagating into unpredictable errors in the unsteady aerodynamics and the control law design. One of the primary objectives of Multi Utility Technology Test Bed, X-56A, aircraft is the flight demonstration of active flutter suppression, and therefore in this study, the identification of the primary and secondary modes for the structural model tuning based on the flutter analysis of X-56A. The ground vibration test validated structural dynamic finite element model of the X-56A is created in this study. The structural dynamic finite element model of the X-56A is improved using a model tuning tool. In this study, two different weight configurations of the X-56A have been improved in a single optimization run.

structural dynamic model tuning↗
NASA NTRSDate not supplied

NASA's Current Optical Communications Efforts

NASA continues to make significant investments in optical communications technology for near Earth and deep space applications. Optical communications will enable new science and exploration missions by providing high data rates and better navigation over long distances. Small low mass terminals, even at low data rates, is also extremelty beneficial to NASA. In 2021, NASA will launch the Laser Communications Relay Demonstration (LCRD) on a Department of Defense Space Test Program satellite. LCRD consists of two optical terminals in geosynchronous (GEO) orbit and two ground stations, and it is a joint project between NASA’s Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory, California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL). Also in 2021, GSFC and MIT/LL will fly the TeraByte InfraRed Delivery (TBIRD) 200 Gbps Cubesat Demo in Low Earth Orbit. In 2022, JPL will launch Psyche to a unique metal asteroid orbiting the Sun between Mars and Jupiter. Psyche will carry the Deep Space Optical Communications (DSOC) payload. In 2023, NASA will do a lunar flyby with the first crewed mission of the Orion spacecraft and it will carry the MIT/LL developed Optical to Orion (O2O) payload. In addition to these flight demonstrations of optical communications, NASA is also working with civil space agencies around the world to develop international standards for optical communications via the Interagency Operations Advisory Group (IOAG) and the Consultative Committee for Space Data Systems (CCSDS).

Bernard L Edwards↗
NASA NTRS2013

Surface Telerobotics: Development and Testing of a Crew Controlled Planetary Rover System

In planning for future exploration missions, architecture and study teams have made numerous assumptions about how crew can be telepresent on a planetary surface by remotely operating surface robots from space (i.e. from a flight vehicle or deep space habitat). These assumptions include estimates of technology maturity, existing technology gaps, and operational risks. These assumptions, however, have not been grounded by experimental data. Moreover, to date, no crew-controlled surface telerobot has been fully tested in a high-fidelity manner. To address these issues, we developed the "Surface Telerobotics" tests to do three things: 1) Demonstrate interactive crew control of a mobile surface telerobot in the presence of short communications delay. 2) Characterize a concept of operations for a single astronaut remotely operating a planetary rover with limited support from ground control. 3) Characterize system utilization and operator work-load for a single astronaut remotely operating a planetary rover with limited support from ground control.

Bualat, Maria G.↗
NASA NTRS1996

Atmospheric Turbulence Statistics from GOLD Experiments

The Ground-Orbiter Lasercomm Demonstration (GOLD) is an international co-operative effort between NASA, NASDA, CRL, and JPL involving optical communication experiments between the Table Mountain Observatory (TMF) and the Japanese Engineering Test Satellite (ETS-VI). Experiments verify the feasibility of daytime acquisition and tracking in two-way space-to-ground laser communication from geostationary ranges using multibeam uplinks. Experimental data clearly show significant reduction in scintillation with multiple beams. Collected data includes a combination of atmospheric effects as well as spacecraft vibrations and pointing errors. Furthur analyses are required to deconvolve these effects.

optical↗
NASA NTRS1972

Solar-electric propulsion breadboard thrust subsystem

A solar-electric propulsion breadboard thrust subsystem has been designed, built, and tested. A 1500-h test was performed to demonstrate the functional capabilities of the subsystem. Described are the subsystem functions and testing process. The results show that the ground work has been established for development of an engineering model of the thrust subsystem.

Masek, T. D.↗
NASA NTRS1977

Ion beam plume and efflux characterization flight experiment study

A flight experiment and flight experiment package for a shuttle-borne flight test of an 8-cm mercury ion thruster was designed to obtain charged particle and neutral particle material transport data that cannot be obtained in conventional ground based laboratory testing facilities. By the use of both ground and space testing of ion thrusters, the flight worthiness of these ion thrusters, for other spacecraft applications, may be demonstrated. The flight experiment definition for the ion thruster initially defined a broadly ranging series of flight experiments and flight test sensors. From this larger test series and sensor list, an initial flight test configuration was selected with measurements in charged particle material transport, condensible neutral material transport, thruster internal erosion, ion beam neutralization, and ion thrust beam/space plasma electrical equilibration. These measurement areas may all be examined for a seven day shuttle sortie mission and for available test time in the 50 - 100 hour period.

Sellen, J. M., Jr.↗
NASA NTRS1989

Rebuilding the space technology base

NASA's Civil Space Technology Initiative (CSTI) will not only develop novel technologies for space exploration and exploitation, but also take mature technologies into their demonstration phase in earth orbit. In the course of five years, CSTI will pay off in ground- and space-tested hardware, software, processes, methods for low-orbit transport and operation, and fundamental scientific research on the orbital environment. Attention is given to LOX/hydrogen and LOX/hydrocarbon reusable engines, liquid/solid fuel hybrid boosters, and aeroassist flight experiments for the validation of aerobraking with atmospheric friction. Also discussed are advanced scientific sensors, systems autonomy and telerobotics, control of flexible structures, precise segmented reflectors, high-rate high-capacity data handling, and advanced nuclear power systems.

Povinelli, Frederick P.↗
NASA NTRS1996

Atmospheric Turbulence Statistics from GOLD Experiments

Ground-Orbiter Lasercomm Demonstration (GOLD) includes the following: (1) Optical communication experiments between Table Mountain Observatory (TMF) and Japanese Engineering Test Satellite (ETS-VI); (2) International cooperative effort between NASA, NASDA, CRL and JPL; and (3) Phase 1 transmissions from October 1995 to January 1996 and Phase 2 transmissions from March 1996 to May 1996.

Jeganathan, Muthu↗