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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

The Spaceflight and Tracking Data Network data handling system in the 1980's

The NASA Spaceflight Tracking and Data Network (STDN) in the 1980's will employ the Tracking and Data Relay Satellite System (TDRSS). The TDRSS includes a pair of geosynchronously orbiting communications satellites which will relay data from most NASA earth-orbiting spacecraft directly to a TDRSS ground station in the U.S. A description is given of the expected evolution of the STDN, the supporting NASCOM, and the integrated communications and data handling configurations that will be needed for NASA space missions in the 1980's.

Dickinson, W. B.↗
NASA NTRS2000

Real-time transmission of full-motion echocardiography over a high-speed data network: impact of data rate and network quality of service

With high-resolution network transmission required for telemedicine, education, and guided-image acquisition, the impact of errors and transmission rates on image quality needs evaluation. METHODS: We transmitted clinical echocardiograms from 2 National Aeronautics and Space Administration (NASA) research centers with the use of Motion Picture Expert Group-2 (MPEG-2) encoding and asynchronous transmission mode (ATM) network protocol over the NASA Research and Education Network. Data rates and network quality (cell losses [CLR], errors [CER], and delay variability [CVD]) were altered and image quality was judged. RESULTS: At speeds of 3 to 5 megabits per second (Mbps), digital images were superior to those on videotape; at 2 Mbps, images were equivalent. Increasing CLR caused occasional, brief pauses. Extreme CER and CDV increases still yielded high-quality images. CONCLUSIONS: Real-time echocardiographic acquisition, guidance, and transmission is feasible with the use of MPEG-2 and ATM with broadcast quality seen above 3 Mbps, even with severe network quality degradation. These techniques can be applied to telemedicine and used for planned echocardiography aboard the International Space Station.

NASA Discipline Cardiopulmonary↗
NASA NTRS1994

The network data delivery service: A real-time data connectivity system

A network data-sharing system, the Network Data Delivery Service (NDDS), is discussed. The NDDS system relies on a bipartite model consisting of the following: information producers (sources) and information consumers (sinks). The example provided by a dual-arm robotic system is examined.

Pardo-Castellote, Gerardo↗
NASA NTRS1993

Design and implementation considerations of a MSAT packet data network

The Mobile Data System, which is intended to provide for packet switched data services is currently under development. The system is based on a star network topology consisting of a centralized Data Hub (DH) serving a large number of mobile terminals. Through the Data Hub, end-to-end connections can be established between terrestrial users on public or private data networks and mobile users. The MDS network will be capable of offering a variety of services some of which are based on the standard X.25 network interface protocol, and others optimized for short messages and broadcast messages. A description of these services and the trade-offs in the DH design are presented.

Karam, Fouad G.↗
NASA NTRS1990

World-wide interactive access to scientific databases via satellite and terrestrial data network

In order to demonstrate the possibilities for scientific networking and data transfer, a first temporary satellite network link was installed between Czecholovakia and the European space operations center in Darmstadt, during the meeting of the inter-agency consultative group for space science in Prague. Several experiments to show interactive nature of the facility and the capability of the system were carried out, and it was proven that, despite the temporary nature of the installation, the planned demonstrations could be conducted in real time. Demonstrations included electronic mail message, orbit prediction and solar X-ray data. The results of the experiment provided insight into possibilities of data exchange.

Sanderson, T. R.↗
NASA NTRS2012

Characterization of HIRF Susceptibility Threshold for a Prototype Implementation of an Onboard Data Network

An experiment was conducted to characterize the effects of HIRF-induced upsets on a prototype onboard data network. The experiment was conducted at the NASA Langley Research Center s High Intensity Radiation Field Laboratory and used a generic distributed system prototyping platform to realize the data network. This report presents the results of the hardware susceptibility threshold characterization which examined the dependence of measured susceptibility on factors like the frequency and modulation of the radiation, layout of the physical nodes and position of the nodes in the test chamber. The report also includes lessons learned during the development and execution of the experiment.

Torres-Pomales, Wilfredo↗
NASA NTRS2008

Read You Loud and Clear! The Story of NASA's Spaceflight Tracking and Data Network

A historical account is provided of NASA's Spaceflight Tracking and Data Network (STDN), starting with its formation in the late 1950s to what it is today in the first decade of the 21st century. It traces the roots of the tracking network from its beginnings at the White Sands Missile Range in New Mexico to the Tracking and Data Relay Satellite System space-based constellation of today. The story spans the early days of satellite tracking using the Minitrack Network, through the expansion of the Satellite Tracking and Data Acquisition Network and the Manned Space Flight Network, and finally, to the Space and Ground networks of today. These accounts tell how international goodwill and foreign cooperation were crucial to the operation of the network and why the space agency chose to build the STDN as it did.

Tsiao, Sunny↗
NASA NTRS1990

Seismotectonics of thin- and thick-skinned deformation in the Andean foreland from local network data - Evidence for a seismogenic lower crust

Local network data from San Juan, Argentina, provides new information about crustal seismicity in the Andean foreland above a horizontal segment of the subducted Nazca Plate. Two areas of foreland seismicity are found, one associated with the Sierras Pampeanas basement uplifts, and the other beneath, but not within, the Precordillera foreland fold-thrust belt. The Precordillera seismicity provides direct evidence for basement deformation beneath the sediments of the thrust belt and supports the idea that its eastern part is significantly modified by underlying basement deformation. In both areas, events are concentrated between 15 and 35 km depth and have volumetric, rather than planar, faultlike distributions. The depth distribution is unusually deep for intraplate earthquakes and suggests a brittle-ductile transition near 30-35 km.

Smalley, Robert, Jr.↗
NASA NTRS2006

The NASA Space Communications Data Networking Architecture

The NASA Space Communications Architecture Working Group (SCAWG) has recently been developing an integrated agency-wide space communications architecture in order to provide the necessary communication and navigation capabilities to support NASA's new Exploration and Science Programs. A critical element of the space communications architecture is the end-to-end Data Networking Architecture, which must provide a wide range of services required for missions ranging from planetary rovers to human spaceflight, and from sub-orbital space to deep space. Requirements for a higher degree of user autonomy and interoperability between a variety of elements must be accommodated within an architecture that necessarily features minimum operational complexity. The architecture must also be scalable and evolvable to meet mission needs for the next 25 years. This paper will describe the recommended NASA Data Networking Architecture, present some of the rationale for the recommendations, and will illustrate an application of the architecture to example NASA missions.

Israel, David J.↗
NASA NTRS1975

Spaceflight tracking and data network support in the space tug era

This paper describes the Spaceflight Tracking and Data Network (STDN) which will be used to provide command, telemetry and tracking support to the Space Tug in the 1980's. A description of the mission support capabilities of the two major elements of the STDN - the ground based sites (GSTDN) and the Tracking and Data Relay Satellite System (TDRSS) - is provided. This paper also contains a summary description of the mission/STDN RF and Data Handling interface.

Stelter, L. R.↗
NASA NTRS1987

Verification of mesoscale objective analyses of VAS and rawinsonde data using the March 1982 AVE/VAS special network data

Various combinations of VAS (Visible and Infrared Spin Scan Radiometer Atmospheric Sounder) data, conventional rawinsonde data, and gridded data from the National Weather Service's (NWS) global analysis, were used in successive-correction and variational objective-analysis procedures. Analyses are produced for 0000 GMT 7 March 1982, when the VAS sounding distribution was not greatly limited by the existence of cloud cover. The successive-correction (SC) procedure was used with VAS data alone, rawinsonde data alone, and both VAS and rawinsonde data. Variational techniques were applied in three ways. Each of these techniques was discussed.

Doyle, James D.↗
NASA NTRS1988

Verification of mesoscale objective analyses of VAS and rawinsode data using the March 1982 AVE/VAS special network data

Various combinations of VAS (Visible and Infrared Spin Scan Radiometer Atmospheric Sounder) data, conventional rawinsonde data, and gridded data from the National Weather Service's (NWS) global analysis, were used in successive-correction and variational objective-analysis procedures. Analyses are produced for 0000 GMT 7 March 1982, when the VAS sounding distribution was not greatly limited by the existence of cloud cover. The successive-correction (SC) Procedure was used with VAS data alone, rawinsonde data alone, and both VAS and rawinsonde data. Variational techniques were applied in three ways. Each of these techniques was discussed.

Doyle, James D.↗
NASA NTRS2001

QoS for Real Time Applications over Next Generation Data Networks

Viewgraphs on Qualtity of Service (QOS) for real time applications over next generation data networks are presented. The progress to date include: Task 1: QoS in Integrated Services over DiffServ networks (UD); Task 2: Interconnecting ATN with the next generation Internet (UD); Task 3: QoS in DiffServ over ATM (UD); Task 4: Improving Explicit Congestion Notification with the Mark-Front Strategy (OSU); Task 5: Multiplexing VBR over VBR (OSU); and Task 6: Achieving QoS for TCP traffic in Satellite Networks with Differentiated Services (OSU).

Ivancic, William↗
NASA NTRS1981

The evolution of the spaceflight tracking and data network

The evolution of the Minitrack Network, the first worldwide satellite tracking capability (1957-1962), into the Satellite Tracking and Data Acquisition Network (1960-1966) is described. Attention is also given to the Mercury Network, which became operational in 1961, was the foundation for the Manned Space Flight Network, and supported the Gemini and Apollo missions. The development of the NASA Communications Network, which began to take shape in the early 1960s, is described. An account is also given of the way in which all these functions began playing together (1965) and were consolidated in the early 1970s as the Space Tracking and Data Network.

Hocking, W. M.↗