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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 1,693 records · Page 94
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Ocean topography experiment (TOPEX/Poseidon): Emergency support

The DSN (Deep Space Network) mission support requirements for the Ocean Topography Experiment (TOPEX/Poseidon) and the Global Positioning System (GPS) demonstration are summarized. The TOPEX mission consists of a single spacecraft which will be placed in a high earth circular orbit, with an altitude of 1334 km and a 63-deg inclination. The TOPEX mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; and tracking support responsibility.

Stiver, R. A.↗
NASA NTRS1991

Pioneer 6 through 8

The DSN (Deep Space Network) mission support requirements for Pioneer 6, 7 and 8 are summarized. The primary objective of these Pioneer missions is to collect scientific data relative to interplanetary phenomena within a range of approximately 0.8 to 1.2 astronomical units from the sun. Following orbital injection, each spacecraft was oriented with its spin axis normal to the ecliptic plane so that the high gain antenna pattern would be aligned with Earth's orbit. The mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profiles; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

Lozier, D.↗
NASA NTRS1991

Pioneer 10 and 11

The DSN (Deep Space Network) mission support requirements for Pioneer 10 and 11 are summarized. The primary objective of these Pioneer missions is to investigate the interplanetary medium beyond the orbit of Saturn and, in particular, to gather data which may locate the heliopause as these spacecraft cruise out of the solar system to the extreme of their communication capabilities. The mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

Lozier, D.↗
NASA NTRS1991

Pioneer 12 (PN-12)

The DSN (Deep Space Network) mission support requirements for Pioneer 12 are summarized. The Pioneer 12 spacecraft is in a 24-hour elliptical orbit around Venus. Atmospheric and altimetry data are obtained mainly around periapsis, and planetary imaging is normally performed around apoapsis. The Pioneer 12 mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

Lozier, D.↗
NASA NTRS1991

Roentgensatellit (ROSAT)

The DSN (Deep Space Network) mission support requirements for ROSAT (Roentgensatellit) are summarized. ROSAT is an international cooperative program between NASA and the Bundesministerium fuer Forschung and Technologie (BMFT). The satellite was launched on a Delta 2 vehicle and placed in a circular orbit at an altitude of 580 km, with a 53-deg inclination. The mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry and command; and tracking support responsibility.

Guckenbiehl, F.↗
NASA NTRS1991

SAMPEX

The DSN (Deep Space Network) mission support requirements for SAMPEX are summarized. SAMPEX is the first mission of the GSFC Small Explorer Satellite program (SMEX). Its primary scientific objectives are to measure the elemental and isotopic composition of solar energetic particles, anomalous cosmic rays, and galactic cosmic rays over the energy range from approximately one to several hundred MeV per nucleon. The SAMPEX mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

Catena, J.↗
NASA NTRS1991

SOLAR-A

The DSN (Deep Space Network) mission support requirements for SOLAR-A are summarized. The SOLAR-A mission objectives are to investigate high energy phenomena of the Sun using x-ray telescopes and spectrometers during the maximum activity period of the solar cycle. The spacecraft will be launched into a circular earth orbit of approximately 500 km altitude and 31 deg inclination. The mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

Ninomiya, K.↗
NASA NTRS1991

Telecom 2-A (TC2A)

The DSN (Deep Space Network) mission support requirements for Telecom 2-A (TC2A) are summarized. The Telecom 2-A will provide high-speed data link applications, telephone, and television service between France and overseas territories. The mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

Dulac, J.↗
NASA NTRS1991

Telecom 2-B and 2-C (TC2B and TC2C)

The DSN (Deep Space Network) mission support requirements for Telecom 2-B and 2-C (TC2B and TC2C) are summarized. These Telecom missions will provide high-speed data link applications, telephone, and television service between France and overseas territories as a follow-on to TC2A. Mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

Dulac, J.↗
NASA NTRS1991

Tracking and Data Relay Satellite System (TDRSS)

The DSN (Deep Space Network) mission support requirements for the Tracking and Data Relay Satellite System (TDRSS) are summarized. The TDRSS consists of four identical satellites in geosynchronous orbits (35,800 km) and a dedicated ground station. The payload of each satellite is a telecommunications service system that relays communication signals between low earth-orbiting user spacecraft and the TDRSS ground terminal. Mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

Mckenzie, J.↗
NASA NTRS1991

Ulysses

The DSN (Deep Space Network) mission support requirements for Ulysses are summarized. The primary goal of the Ulysses mission is to explore the Sun, its environment, and possible links between solar variability and terrestrial weather and climate. The Ulysses spacecraft will be injected into an interplanetary orbit toward Jupiter after which the spacecraft travels in a heliocentric, out-of-ecliptic orbit with high heliographic inclination. The Ulysses mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

Meeks, W.↗
NASA NTRS1991

Upper Atmosphere Research Satellite (UARS): Emergency support

The DSN (Deep Space Network) mission support requirements for the Upper Atmospheric Research Satellite (UARS) are summarized. The UARS satellite will be placed into a circular orbit of 600 km and 57 deg inclination with a period of 97 minutes. The mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

Osler, S.↗
NASA NTRS1991

Voyager Interstellar Mission (VIM)

The DSN (Deep Space Network) mission support requirements for the Voyager Interstellar Mission (VIM) are summarized. The general objectives of the VIM are to investigate the interplanetary and interstellar media and to continue the Voyager program of ultraviolet astronomy. The VIM will utilize both Voyager spacecraft for the period from January 1990 through December 2019. The mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, control and support systems; and tracking support responsibility.

Rudd, R.↗
NASA NTRS1991

Mark 4A antenna control system data handling architecture study

A high-level review was conducted to provide an analysis of the existing architecture used to handle data and implement control algorithms for NASA's Deep Space Network (DSN) antennas and to make system-level recommendations for improving this architecture so that the DSN antennas can support the ever-tightening requirements of the next decade and beyond. It was found that the existing system is seriously overloaded, with processor utilization approaching 100 percent. A number of factors contribute to this overloading, including dated hardware, inefficient software, and a message-passing strategy that depends on serial connections between machines. At the same time, the system has shortcomings and idiosyncrasies that require extensive human intervention. A custom operating system kernel and an obscure programming language exacerbate the problems and should be modernized. A new architecture is presented that addresses these and other issues. Key features of the new architecture include a simplified message passing hierarchy that utilizes a high-speed local area network, redesign of particular processing function algorithms, consolidation of functions, and implementation of the architecture in modern hardware and software using mainstream computer languages and operating systems. The system would also allow incremental hardware improvements as better and faster hardware for such systems becomes available, and costs could potentially be low enough that redundancy would be provided economically. Such a system could support DSN requirements for the foreseeable future, though thorough consideration must be given to hard computational requirements, porting existing software functionality to the new system, and issues of fault tolerance and recovery.

Briggs, H. C.↗
NASA NTRS1992

Summer graduate research program for interns in science and engineering

The goal of the 10 week graduate intern program was to increase the source of candidates for positions in science and engineering at the Goddard Space Flight Center. Students participating in this program submitted papers on the work they performed over the 10 week period and also filled out questionnaires on the program's effectiveness, their own performance, and suggestions on improvements. The topics covered by the student's papers include: microsoft excel applications; fast aurora zone analysis; injection seeding of a Q-switched alexandrite laser; use of high temperature superconductors; modifications on a communication interface board; modeling of space network activities; prediction of atmospheric ozone content; and applications of industrial engineering.

Lee, Clinton B.↗
NASA NTRS1992

The X-windows interactive navigation data editor

A new computer program called the X-Windows Interactive Data Editor (XIDE) was developed and demonstrated as a prototype application for editing radio metric data in the orbit-determination process. The program runs on a variety of workstations and employs pull-down menus and graphical displays, which allow users to easily inspect and edit radio metric data in the orbit data files received from the Deep Space Network (DSN). The XIDE program is based on the Open Software Foundation OSF/Motif Graphical User Interface (GUI) and has proven to be an efficient tool for editing radio metric data in the navigation operations environment. It was adopted by the Magellan Navigation Team as their primary data-editing tool. Because the software was designed from the beginning to be portable, the prototype was successfully moved to new workstation environments. It was also itegrated into the design of the next-generation software tool for DSN multimission navigation interactive launch support.

Rinker, G. C.↗
NASA NTRS1992

Pointing-error simulations of the DSS-13 antenna due to wind disturbances

Accurate spacecraft tracking by the NASA Deep Space Network (DSN) antennas must be assured during changing weather conditions. Wind disturbances are the main source of tracking errors. The development of a wind-force model and simulations of wind-induced pointing errors of DSN antennas are presented. The antenna model includes the antenna structure, the elevation and azimuth servos, and the tracking controller. Simulation results show that pointing errors due to wind gusts are of the same order as errors due to static wind pressure and that these errors (similar to those of static wind pressure) satisfy the velocity quadratic law. The presented methodology is used for wind-disturbance estimation and for the design of an antenna controller with wind-disturbance rejection properties.

Gawronski, W.↗
NASA NTRS1992

A microwave holography methodology for diagnostics and performance improvement for large reflector antennas

This microwave holography technique utilizes the Fourier transform relation between the complex far field radiation pattern of an antenna and the complex aperture field distribution. Resulting aperture phase and amplitude distribution data can be used to precisely characterize various crucial performance parameters, including panel alignment, panel shaping, subreflector position, antenna aperture illumination, directivity at various frequencies, and gravity deformation effects. The methodology of data processing presented here was successfully applied to the Deep Space Network (DSN) 34-m beam waveguide antennas. The antenna performance was improved at all operating frequencies by reducing the main reflector mechanical surface rms error to 0.43 mm. At Ka-band (32 GHz), the estimated improvement is 4.1 dB, resulting in an aperture efficiency of 52 percent. The performance improvement was verified by efficiency measurements and additional holographic measurements.

Rochblatt, D. J.↗