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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Telescience at the University of California, Berkeley

The University of California at Berkeley (UCB) is a member of a university consortium involved in telescience testbed activities under the sponsorship of NASA. Our Telescience Testbed Project consists of three experiments using flight hardware being developed for the Extreme Ultraviolet Explorer project at UCB's Space Sciences Laboratory. The first one is a teleoperation experiment investigating remote instrument control using a computer network such as the Internet. The second experiment is an effort to develop a system for operation of a network of remote workstations allowing coordinated software development, evaluation, and use by widely dispersed groups. The final experiment concerns simulation as a method to facilitate the concurrent development of instrument hardware and support software. We describe our progress in these areas.

Telemetry/instrumentation/methods↗
NASA NTRS1992

An assembly to provide a time reference for the JPL Network Operations Control Center, Real-Time

A device is described which provides the value of date coordinated universal time (date UTC) to the JPL Network Operations Control Center, Real Time (NOCC-RT) facility. The NOCC-RT is the real time portion of the NOCC upgrade task. The time scale is generated in the NOCC-RT clock processor; however, there is a continuous reference to UTC, as realized by the National Institute of Standards and Technology and transmitted by Earth orbiting satellites. An important functional design requirement is the 99.9 pct. availability.

Clements, P. A.↗
NASA NTRS1975

Station coordinates in the standard earth 3 system and radiation-pressure perturbations from ISAGEX camera data

Simultaneous and individual camera observations of GEOS 1, GEOS 2, Pageos, and Midas 4 obtained during the International Satellite Geodesy Experiment are utilized to determine station coordinates. The Smithsonian Astrophysical Observatory Standard Earth III system of coordinates is used to tie the geometrical network to a geocentric system and as a reference for calculating satellite orbits. A solution for coordinates combining geometrical and dynamical methods is obtained, and a comparison between the solutions and terrestrial data is made. The radiation-pressure and earth-albedo perturbations for Pageos are very large, and Pageos' orbits are used to evaluate the analytical treatment of these perturbations. Residual effects, which are probably of interest to aeronomists, remain in the Pageos orbits.

Gaposchkin, E. M.↗
NASA NTRS1979

A telephone multiline signaling system

Telephone system interconnects users of from one to eight telephone lines in network. System is useful in coordinating activities in large plants and installations. It permits spontaneous conferences, paging, and monitoring from key locations.

Toole, P. C.↗
NASA NTRS1984

Satellite Precipitation and Cloud Experiment (SPACE)

An experiment plan was formulated to support an investigation of the precipitation processes associated with mesoscale systems and the interaction of rain producing cloud complexes with the meso and macro-scale environment. The field program necessary to accomplish the scientific goals is designed to incorporate satellite information (VIS and IR as well as VAS data), special radiosonde and surface observing capabilities, radar observations of storms development, special observations from aircraft and ground based lightning measurements. The observing network comprises rawinsonde stations located in northern Alabama and eastern Tennessee. A high density raingauge network and the MSFC lightning location network also cover the area. Coordination with NASA U2 and ER2 aircraft programs and with the operational requirements of the microburst severe thunderstorm program can assure the most efficient utilization of the observing resources.

Arnold, J. E.↗
NASA NTRS1988

Telescience at the University of California, Berkeley

The University of California at Berkeley (UCB) is a member of a university consortium involved in telescience testbed activities under the sponsorship of NASA. The Telescience Testbed Project consists of three experiments using flight hardware being developed for the Extreme Ultraviolet Explorer project at UCB's Space Sciences Laboratory. The first one is a teleoperation experiment investigating remote instrument control using a computer network such as the Internet. The second experiment is an effort to develop a system for operation of a network of remote workstations allowing coordinated software development, evaluation, and use by widely dispersed groups. The final experiment concerns simulation as a method to facilitate the concurrent development of instrument hardware and support software. Progress in these areas is described.

Chakrabarti, S.↗
NASA NTRS1990

International Space Network interoperability results and status

In 1986, NASA, ESA, and NASDA instituted the Space Network Interoperability Panel (SNIP) to coordinate the activities of these three national agencies during the exploratory phase of new space communications systems' development. To date, the deliberations of SNIP have led to (1) ESA's changing of its European Data Relay Satellite's S-band center frequency from fixed to tunable, (2) NASDA's changing of two comsats' Ka-band return link frequency from 32 GHz to the 26 GHz standard adopted by ESA, and (3) NASA's adoption of the Ka-band, in addition to the Ku-band, as the high data rate interorbital link of the ATDRS. A tabulation of interoperability considerations for the three space agencies is presented.

Fahnestock, Dale↗
NASA NTRS1992

Cerebellar neurocontroller project, for aerospace applications, in a civilian neurocomputing initiative in the 'decade of the brain'

A key question is how to utilize civilian government agencies along with an industrial consortium to successfully complement the so far primarily defense-oriented neural network research. Civilian artificial neural system projects, such as artificial cerebellar neurocontrollers aimed at duplicating nature's existing neural network solutions for adaptive sensorimotor coordination, are proposed by such a synthesis. The cerebellum provides an intelligent interface between higher possibly symbolic levels of human intelligence and repetitious demands of real world conventional controllers. The generation of such intelligent interfaces could be crucial to the economic feasibility of the human settlement of space and an improvement in telerobotics techniques to permit the cost-effective exploitation of nonterrestrial materials and planetary exploration and monitoring. The authors propose a scientific framework within which such interagency activities could effectively cooperate.

Pellionisz, Andras J.↗
NASA NTRS2007

DSN Resource Scheduling

TIGRAS is client-side software, which provides tracking-station equipment planning, allocation, and scheduling services to the DSMS (Deep Space Mission System). TIGRAS provides functions for schedulers to coordinate the DSN (Deep Space Network) antenna usage time and to resolve the resource usage conflicts among tracking passes, antenna calibrations, maintenance, and system testing activities. TIGRAS provides a fully integrated multi-pane graphical user interface for all scheduling operations. This is a great improvement over the legacy VAX VMS command line user interface. TIGRAS has the capability to handle all DSN resource scheduling aspects from long-range to real time. TIGRAS assists NASA mission operations for DSN tracking of station equipment resource request processes from long-range load forecasts (ten years or longer), to midrange, short-range, and real-time (less than one week) emergency tracking plan changes. TIGRAS can be operated by NASA mission operations worldwide to make schedule requests for the DSN station equipment.

Wang, Yeou-Fang↗
NASA NTRS2005

Transformational Spaceport and Range Concept of Operations: A Vision to Transform Ground and Launch Operations

The Transformational Concept of Operations (CONOPS) provides a long-term, sustainable vision for future U.S. space transportation infrastructure and operations. This vision presents an interagency concept, developed cooperatively by the Department of Defense (DoD), the Federal Aviation Administration (FAA), and the National Aeronautics and Space Administration (NASA) for the upgrade, integration, and improved operation of major infrastructure elements of the nation s space access systems. The interagency vision described in the Transformational CONOPS would transform today s space launch infrastructure into a shared system that supports worldwide operations for a variety of users. The system concept is sufficiently flexible and adaptable to support new types of missions for exploration, commercial enterprise, and national security, as well as to endure further into the future when space transportation technology may be sufficiently advanced to enable routine public space travel as part of the global transportation system. The vision for future space transportation operations is based on a system-of-systems architecture that integrates the major elements of the future space transportation system - transportation nodes (spaceports), flight vehicles and payloads, tracking and communications assets, and flight traffic coordination centers - into a transportation network that concurrently accommodates multiple types of mission operators, payloads, and vehicle fleets. This system concept also establishes a common framework for defining a detailed CONOPS for the major elements of the future space transportation system. The resulting set of four CONOPS (see Figure 1 below) describes the common vision for a shared future space transportation system (FSTS) infrastructure from a variety of perspectives.

Source record↗
NASA NTRSDate not supplied

Separation Assurance in Urban Air Mobility Systems Using Shared Scheduling Protocols

Ensuring safe separation between aircraft is a critical challenge in air traffic management, particularly in urban air mobility (UAM) environments where high traffic density and low altitudes require precise control. In these environments, conflicts often arise at the intersections of flight corridors, posing significant risks. We propose a tactical separation approach leveraging shared scheduling protocols, originally designed for Ethernet networks and operating systems, to coordinate access to these intersections. Using a decentralized Markov decision process framework, the proposed approach enables aircraft to autonomously adjust their speed and timing as they navigate these critical areas, maintaining safe separation without a central controller. We evaluate the effectiveness of this approach in simulated UAM scenarios, demonstrating its ability to reduce separation violations to zero while acknowledging trade-offs in flight times as traffic density increases. Additionally, we explore the impact of non-compliant aircraft, showing that while shared scheduling protocols can no longer guarantee safe separation, they still provide significant improvements over systems without scheduling protocols.

Separation Assurance↗
NASA NTRSDate not supplied

Separation Assurance in Urban Air Mobility Systems Using Shared Scheduling Protocols

Ensuring safe separation between aircraft is a critical challenge in air traffic management, particularly in urban air mobility (UAM) environments where high traffic density and low altitudes require precise control. In these environments, conflicts often arise at the intersections of flight corridors, posing significant risks. We propose a tactical separation approach leveraging shared scheduling protocols, originally designed for Ethernet networks and operating systems, to coordinate access to these intersections. Using a decentralized Markov decision process framework, the proposed approach enables aircraft to autonomously adjust their speed and timing as they navigate these critical areas, maintaining safe separation without a central controller. We evaluate the effectiveness of this approach in simulated UAM scenarios, demonstrating its ability to reduce separation violations to zero while acknowledging trade-offs in flight times as traffic density increases. Additionally, we explore the impact of non-compliant aircraft, showing that while shared scheduling protocols can no longer guarantee safe separation, they still provide significant improvements over systems without scheduling protocols.

system safety↗
NASA NTRS1994

The evolution of magnetic network elements in the quiet Sun

Using the 155-h coordinated magnetograph data of Huairou and Big Bear Solar Observatories, we have studied the evolution and lifetime of magnetic network elements in an enhanced network region. Both statistical and counting methods give a mean lifetime of network elements of 50h. The network elements are divided into two categories according to their evolution: 'breakup' and 'merging'. They have similar average lifetimes. We also find that the number of the elements that disappear by merging is about twice that by breakup. This may indicate that the creation and disappearance of magnetic network elements are balanced.

Liu, Y.↗
NASA NTRS2004

Coordination of Mars Orbiting Assets to Support Entry, Descent, and Landing (EDL) Activities

NASA policy requires continuous telecommunications with missions during the execution of their critical events, which implies constraints on where missions to other planets may land or inject into orbit. JPL is working to establish a telecommunications network at Mars to provide contact with inbound missions to Mars and assets that have landed on the Martian surface, thus reducing the constraints on where critical events may be performed. Coordination of network assets is required to cover an inbound mission's critical event, such as EDL. This paper describes the development of a tool to evaluate EDL coverage capability of Mars network assets over a specified launch date/arrival date space.

Mars Network↗
NASA NTRS1977

National Geodetic Satellite Program, Part II: Ohio State University

Data analysis was carried out to obtain an improved global network combining all participating tracking stations in a single worldwide coordinate system. Mathematical formulations were derived, programmed, and tested. Observational data were used to determine the relative positions of tracking stations in an arbitrary Cartesian coordinate system. The position of this coordinate system was estimated with respect to an absolute system. A primary network was established in which station positions were known to an internal consistency of 10 meters or better for the following purposes: (1) to establish the relative relationships between the various geodetic datums in use around the world; and (2) to connect isolated tracking stations, islands, navigational beacons, and other points of interest. Results are presented.

Mueller, I. I.↗
NASA NTRSDate not supplied

Synchronizing the Cosmos: The Critical Role of Timekeeping Systems in Gateway's Operational Success

This paper explores the critical role of Universal Spacecraft Time (UST) in the operation of National Aeronautics and Space Administration’s (NASA) Lunar Gateway, a central component of the Artemis program aimed at establishing a sustained human presence on the Moon and facilitating future manned missions to Mars. With the Gateway's design incorporating advanced technologies such as Time-Triggered Ethernet (TTE) for network synchronization, the distinction between network time and UST becomes paramount. UST, defined via the Network Time Protocol (NTP), is essential for coordinating the myriad of operations within the Gateway, from life support systems to scientific experiments. Additionally, the paper will define Mission Elapse Time (MET) and network time, delving into their use and applications within the Gateway framework. This examination provides an in-depth analysis of the challenges in space timekeeping, the implementation and management of UST, MET, and network time, and their pivotal roles in ensuring mission success. Through the precise synchronization of the Gateway's operations, these timekeeping systems not only address the unique temporal dynamics of space travel but also enhance operational efficiency and safety. The paper underscores the indispensable nature of precise timekeeping in the broader context of space exploration, highlighting its implications for future missions and the continued advancement of human capabilities beyond Earth.

Gateway↗
NASA NTRS1982

On the establishment and maintenance of a modern conventional terrestrial reference system

The frame of the Conventional Terrestrial Reference System (CTS) is defined by an adopted set of coordinates, at a fundamental epoxh, of a global network of stations which contribute the vertices of a fundamental polyhedron. A method to estimate this set of coordinates using a combination of modern three dimensional geodetic systems is presented. Once established, the function of the CTS is twofold. The first is to monitor the external (or global) motions of the polyhedron with respect to the frame of a Conventional Inertial Reference System, i.e., those motions common to all stations. The second is to monitor the internal motions (or deformations) of the polyhedron, i.e., those motions that are not common to all stations. Two possible estimators for use in earth deformation analysis are given and their statistical and physical properties are described.

Bock, Y.↗