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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 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Results of thin-route satellite communication system analyses including estimated service costs

A variety of cost and performance tradeoffs are addressed and the preliminary design of a communications satellite system capable of meeting isolated rural users' needs is presented. Small inexpensive rural earth stations are linked via the satellite to a nation wide network of large earth stations which are, in turn, interconnected to the switching exchanges of the conventional telephone network. Optimum earth station EIRP and G/T and satellite transponder power are defined as a function of a wide variety of system options.

Wright, D. L.↗
NASA NTRSDate not supplied

TECHEDSAT-7 and 10: The Little Spacecraft That Could

The NOW (Nanosatellite Orbital Workshop) of NASA Ames Research Center (ARC) has two cubesats in orbit at this time: 6 U TechEdSat-10 (T-10) and the 3U TechEdSat-7 (T-7). T10 was jettisoned from the ISS via the NANORACKS system 7/13/2020, and T-7 was launched via Virgin Orbit 1/17/2021. Both were built by the Nano-satellite Orbital Workshop (NOW) at NASA ARC, and designed and fabricated by interns and students in collaboration with educational institutions. Prototyping novel technologies for non-powered re-entry and communications from orbit are primary research interests, however all subsystems including power generation and distribution, subsystem control, navigation, positioning, heat management etc. extend current technologies. Use of distributed processors using open software platforms and standards other based technologies and software is integral to all segments of spacecraft design. Here, we will present an overview of the spacecraft, experiments, and accomplishments – as well as the next three flight experiments. Some of these experiments include: The exo-brake re-entry system is being developed to enable sample return and end of life disposal; Internal communications for sensors, inter-subsystem and experiments uses both a Zigbee based PAN and internal Wi-Fi for high-speed inter-device communications; The Iridium small message LEO system (Short Burst Data) is used to both command the spacecraft and send data to the ground; Experimental use of the Global-Star system for L-band system comparison and back-up; Collaborative NOAA an experiment to communicate from LEO to the GOES geostationary satellite using the DCS (Data Collection System) with on-board Doppler correction; Mars and Lunar experimental communication systems for future cis-lunar and interplanetary nano-satellites; First demonstration of the NASA Near Earth Network systems with nano-satellites at NASA/Wallops Island; Solar array design and implementation for unique future flexible structures; Power distribution using Tardigrade rad-hard processor omni-board (designed by the team); Distributed processors with internal Wi-Fi connectivity; and Initial experiments with AI/Machine Learning.

M Murbach↗
NASA NTRS1977

Analysis of economics of a TV broadcasting satellite for additional nationwide TV programs

The influence of a TV broadcasting satellite, transmitting four additional TV networks was analyzed. It is assumed that the cost of the satellite systems will be financed by the cable TV system operators. The additional TV programs increase income by attracting additional subscribers. Two economic models were established: (1) each local network is regarded as an independent economic unit with individual fees (cost price model) and (2) all networks are part of one public cable TV company with uniform fees (uniform price model). Assumptions are made for penetration as a function of subscription rates. Main results of the study are: the installation of a TV broadcasting satellite improves the economics of CTV-networks in both models; the overall coverage achievable by the uniform price model is significantly higher than that achievable by the cost price model.

Becker, D.↗
NASA NTRS2001

Future Evolution of NASA's SLR and VLBI Networks

Over the first half of this decade the NASA Space Geodesy Program is planning a major transformation of its existing (Satellite Laser Ranging) SLR network of stations and also further evolutionary changes to its network of (Very Long Base Interferometry) VLBI stations. These network changes will be made to meet the ever more demanding requirements of the earth and space science programs that these networks support while seeking through automation and electronic data communications to increase efficiency and decrease cost of operations and maintenance. The major aspects of the NASA plan will be outlined and the benefits to the scientific community will be addressed.

Bosworth, John M.↗
NASA NTRS1977

Lageos orbital acquisition and initial assessment

Orbital elements for the satellite Lageos, launched on 4 May, 1976, were generated through use of Baker-Nunn camera data. Camera observations of the apogee kick motor provided the node and perigee, the inclination and the eccentricity, while the mean anomaly and the mean motion were determined from observations of the satellite. During the month following the launch, the Smithsonian Astrophysical Observatory and NASA laser tracking networks acquired about 110 satellite passes. The laser tracking system has been applied to a variety of orbital configurations, including elevation angles below 20 deg. Single-pass range residuals versus time were plotted for 741 laser observations of the satellite; the standard deviation of the total system noise was found to be 7 cm.

Pearlman, M. R.↗
NASA NTRS1999

Mars Network Operations Concept

NASA has initiated at Jet Propulsion Laboratory the design of a Communications and Navigation Network at Mars.

NASA Jet Propulsion Laboratory JPL Satellites Mars↗
NASA NTRS2001

Aeronautical-Satellite-Assisted Process Being Developed for Information Exchange Through Network Technologies (Aero-SAPIENT)

Communications technologies are being developed to address safety issues during aviation travel. Some of these technologies enable the aircraft to be in constant bidirectional communications with necessary systems, people, and other aircraft that are not currently in place today. Networking technologies, wireless datalinks, and advanced avionics techniques are areas of particular importance that the NASA Glenn Research Center has contributed. Glenn, in conjunction with the NASA Ames Research Center, NASA Dryden Flight Research Center, and NASA Langley Research Center, is investigating methods and applications that would utilize these communications technologies. In mid-June 2000, the flight readiness of the network and communications technologies were demonstrated via a simulated aircraft. A van simulating an aircraft was equipped with advanced phased-array antennas (Advanced Communications/Air Traffic Management (AC/ATM) Advanced Air Transportation Technologies (AATT) project) that used commercial Ku-band satellite communications to connect Glenn, Dryden, and Ames in a combined system ground test. This test simulated air-ground bidirectional transport of real-time digital audio, text, and video data via a hybrid network configuration that demonstrated the flight readiness of the network and communications technologies. Specifically, a Controller Pilot Data Link Communications application was used with other applications to demonstrate a multiprotocol capability via Internet-protocol encapsulated ATN (Aeronautical Telecommunications Network) data packets. The significance of this combined ground test is its contribution to the Aero Information Technology Base Program Level I milestone (Software Technology investment area) of a real-time data link for the National Airspace System. The objective of this milestone was to address multiprotocol technology applicable for real-time data links between aircraft, a satellite, and the ground as well as the ability to distribute flight data with multilevel priorities among several sites.

Zernic, Michael J.↗
NASA NTRS1995

Network flexibility of the IRIDIUM (R) Global Mobile Satellite System

The IRIDIUM system is a global personal communications system supported by a constellation of 66 low earth orbit (LEO) satellites and a collection of earth-based 'gateway' switching installations. Like traditional wireless cellular systems, coverage is achieved by a grid of cells in which bandwidth is reused for spectral efficiency. Unlike any cellular system ever built, the moving cells can be shared by multiple switching facilities. Noteworthy features of the IRIDIUM system include inter-satellite links, a GSM-based telephony architecture, and a geographically controlled system access process. These features, working in concert, permit flexible and reliable administration of the worldwide service area by gateway operators. This paper will explore this unique concept.

Hutcheson, Jonathan↗
NASA NTRSDate not supplied

The Status of NASA SCaN's Efforts to Integrate Commercial Satellite Communication Service Providers Into the Near Space Network

The National Aeronautics and Space Administration’s (NASA) Space Communication and Navigation (SCaN) program intends to deliver operationally ready commercial space-based communications relay services to missions by 2031. The high-throughput, demand-responsive networks that commercial providers are building and operating will remove long-standing network constraints, enhancing mission capability and data-return.

Near Space Network↗
NASA NTRSDate not supplied

PetitSat - a 6U CubeSat to Examine Plasma Density Enhancements in the Ionosphere

PetitSat is a CubeSat mission designed to examine the link between Medium-Scale Traveling Ionospheric Disturbances (MSTIDs) in the upper atmosphere and plasma density enhancements. The mission will provide in situ measurements of the plasma density, 3D ion drift, as well as ion and neutral composition. The instrument suite includes a combined retarding potential analyzer and cross-track drift meter and an ion-neutral mass spectrometer. This instrument suite will provide comprehensive information about the fluctuations in plasma, as well as changes in the neutral profile. petitSat will launch into a 51 deg inclination orbit at 400 km (consistent with an International Space Station deployment), allowing for numerous conjunctions with the Boston University All-Sky Imager network and GPS receivers from the International Global Navigation Satellite Systems (GNSS) Service (IGS) network over the mission lifetime.

Jeffrey Hamilton Klenzing↗
NASA NTRS1999

The CEOS International Directory Network Progress and Plans: Spring, 1999

The Global Change Master Directory (GCMD) serves as the software development hub for the Committee on Earth Observation Satellites' (CEOS) International Directory Network (IDN). The GCMD has upgraded the software for the IDN nodes as Version 7 of the GCMD: MD7-Oracle and MD7-Isite, as well as three other MD7 experimental interfaces. The contribution by DLR representatives (Germany) of the DLR Thesaurus will be demonstrated as an educational tool for use with MD7-Isite. The software will be installed at twelve nodes around the world: Brazil, Argentina, the Netherlands, Canada, France, Germany, Italy, Japan, Australia, New Zealand, Switzerland, and several sites in the United States. Representing NASA for the International Directory Network and the CEOS Data Access Subgroup, NASA's contribution to this international interoperability effort will be updated. Discussion will include interoperability with the CEOS Interoperability Protocol (CIP), features of the latest version of the software, including upgraded capabilities for distributed input by the IDN nodes, installation logistics, "mirroring', population objectives, and future plans.

Olsen, Lola M.↗
NASA NTRS1999

The CEOS International Directory Network: Progress and Plans, Spring, 1999

The Global Change Master Directory (GCMD) serves as the software development hub for the Committee on Earth observation Satellites' (CEOS) International Directory Network (IDN). The GCMD has upgraded the software for the IDN nodes as Version 7 of the GCMD: MD7-Oracle and MD7-Isite, as well as three other MD7 experimental interfaces. The contribution by DLR representatives (Germany) of the DLR Thesaurus will be demonstrated as an educational tool for use with MD7-Isite. The software will be installed at twelve nodes around the world: Brazil, Argentina, the Netherlands, Canada, France, Germany, Italy, Japan, Australia, New Zealand, Switzerland, and several sites in the United States. Representing NASA for the International Directory Network and the CEOS Data Access Subgroup, NASA's contribution to this international interoperability effort will be updated. Discussion will include interoperability with the CEOS Interoperability Protocol (CIP), features of the latest version of the software, including upgraded capabilities for distributed input by the IDN nodes, installation logistics, "mirroring", population objectives, and future plans.

Olsen, Lola M.↗
NASA NTRS2014

EDSN Development Lessons Learned

The Edison Demonstration of Smallsat Networks (EDSN) is a technology demonstration mission that provides a proof of concept for a constellation or swarm of satellites performing coordinated activities. Networked swarms of small spacecraft will open new horizons in astronomy, Earth observations and solar physics. Their range of applications include the formation of synthetic aperture radars for Earth sensing systems, large aperture observatories for next generation telescopes and the collection of spatially distributed measurements of time varying systems, probing the Earths magnetosphere, Earth-Sun interactions and the Earths geopotential. EDSN is a swarm of eight 1.5U Cubesats with crosslink, downlink and science collection capabilities developed by the NASA Ames Research Center under the Small Spacecraft Technology Program (SSTP) within the NASA Space Technology Mission Directorate (STMD). This paper describes the concept of operations of the mission and planned scientific measurements. The development of the 8 satellites for EDSN necessitated the fabrication of prototypes, Flatsats and a total of 16 satellites to support the concurrent engineering and rapid development. This paper has a specific focus on the development, integration and testing of a large number of units including the lessons learned throughout the project development.

Technology Demonstration↗
NASA NTRS1995

Increasing cellular coverage within integrated terrestrial/satellite mobile networks

When applying the hierarchical cellular concept, the satellite acts as giant umbrella cell covering a region with some terrestrial cells. If a mobile terminal traversing the region arrives to the border-line or limits of a regular cellular ground service, network transition occurs and the satellite system continues the mobile coverage. To adequately assess the boundaries of service of a mobile satellite system an a cellular network within an integrated environment, this paper provides an optimized scheme to predict when a network transition may be necessary. Under the assumption of a classified propagation phenomenon and Lognormal shadowing, the study applies an analytical approach to estimate the location of a mobile terminal based on a reception of the signal strength emitted by a base station.

Castro, Jonathan P.↗
NASA NTRS1999

PV-Diesel Hybrid SCADA Experiment Network Design

The essential features of an experimental network for renewable power system satellite based supervisory, control and data acquisition (SCADA) are communication links, controllers, diagnostic equipment and a hybrid power system. Required components for implementing the network consist of two satellite ground stations, to satellite modems, two 486 PCs, two telephone receivers, two telephone modems, two analog telephone lines, one digital telephone line, a hybrid-power system equipped with controller and a satellite spacecraft. In the technology verification experiment (TVE) conducted by Savannah State University and Florida Solar Energy Center, the renewable energy hybrid system is the Apex-1000 Mini-Hybrid which is equipped with NGC3188 for user interface and remote control and the NGC2010 for monitoring and basic control tasks. This power system is connected to a satellite modem via a smart interface, RS232. Commands are sent to the power system control unit through a control PC designed as PC1. PC1 is thus connected to a satellite model through RS232. A second PC, designated PC2, the diagnostic PC is connected to both satellite modems via separate analog telephone lines for checking modems'health. PC2 is also connected to PC1 via a telephone line. Due to the unavailability of a second ground station for the ACTS, one ground station is used to serve both the sending and receiving functions in this experiment. Signal is sent from the control PC to the Hybrid system at a frequency f(sub 1), different from f(sub 2), the signal from the hybrid system to the control PC. f(sub l) and f(sub 2) are sufficiently separated to avoid interference.

Kalu, Alex↗
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.↗