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All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Telecommunications in cometary environments

Propagation effects on telecommunications in a cometary environment include those due to dust, the inhomogeneous plasma of the coma and tail, and ionization generated by impact of neutral molecules and dust on the spacecraft. Attenuation caused by dust particles is estimated to be on the order of 10 to the minus 5th power dB for the Halley Intercept Mission. Ionization generated by impact on the spacecraft is estimated to result in an electron content of 10 to the 12th power to 10 to the 13th power el/sq meters (3 eV electrons) along the telecommunications path. An estimate of the electron content due to Comet Halley itself is 10 to the 16th power to 10 to the 17th power el/sq meters, compared to a content of 10 to the 16th power to 10 to the 18th power el/sq meters for the Earth's ionosphere and 10 to the 17th power to 10 to the 18th power el/sq meters for the interplanetary medium. The electron content of the plasma near Comet Halley will cause excess range delay, and a Doppler shift of the signal from the spacecraft will occur in propagation to the rate of change of the path electron content. It is recommended that S and X down-link frequencies by employed to monitor the path electron content and amplitude scintillation and spectral broadening of the received signals. These measurements will provide a quantitative base of knowledge that will be valuable for radio science and telecommunications system design purposes.

Flock, W. L.↗
NASA NTRS1985

Telecommunications forecast for ITU Region 2 to the year 1995

Telecommunications activity was studied. The primary objective was to forecast the need for fixed service satellites (FSS) by countries within ITU Region 2 excluding the United States and Greenland. Forecasts of telecommunications equipment needs were developed as a yardstick of the relative level of telecommunications activity among developing countries within the region. A likely scenario for the implementation of domestic and regional communications satellites is forecasted to provide services to and among countries in ITU Region 2. By 1995, it is forecast that 15 fixed service satellites will be implemented. A forecast of the countries requirements indicates that, with the possible exception of Canada, this constellation of satellites will meet these countries' needs to beyond the year 2000.

Hollansworth, J. E.↗
NASA NTRS1989

Telecommunications and navigation systems design for manned Mars exploration missions

This paper discusses typical manned Mars exploration needs for telecommunications, including preliminary navigation support functions. It is a brief progress report on an ongoing study program within the current NASA JPL Deep Space Network (DSN) activities. A typical Mars exploration case is defined, and support approaches comparing microwave and optical frequency performance for both local in situ and Mars-earth links are described. Optical telecommunication and navigation technology development opportunities in a Mars exploration program are also identified. A local Mars system telecommunication relay and navigation capability for service support of all Mars missions has been proposed as part of an overall solar system communications network. The effects of light-time delay and occultations on real-time mission decision-making are discussed; the availability of increased local mass data storage may be more important than increasing peak data rates to earth. The long-term frequency use plan will most likely include a mix of microwave, millimeter-wave and optical link capabilities to meet a variety of deep space mission needs.

Hall, Justin R.↗
NASA NTRS1991

An assessment of technology alternatives for telecommunications and information management for the space exploration initiative

On the 20th anniversary of the Apollo 11 lunar landing, President Bush set forth ambitious goals for expanding human presence in the solar system. The Space Exploration Initiative (SEI) addresses these goals beginning with Space Station Freedom, followed by a permanent return to the Moon, and a manned mission to Mars. A well designed, adaptive Telecommunications, Navigation, and Information Management (TNIM) infrastructure is vital to the success of these missions. Utilizing initial projections of user requirements, a team under the direction of NASA's Office of Space Operations developed overall architectures and point designs to implement the TNIM functions for the Lunar and Mars mission scenarios. Based on these designs, an assessment of technology alternatives for the telecommunications and information management functions was performed. This technology assessment identifies technology developments necessary to meet the telecommunications and information management system requirements for SEI. Technology requirements, technology needs and alternatives, the present level of technology readiness in each area, and a schedule for development are presented.

Ponchak, Denise S.↗
NASA NTRS1991

Tropical medicine: Telecommunications and technology transfer

The potential for global outbreaks of tropical infectious diseases, and our ability to identify and respond to such outbreaks is a major concern. Rapid, efficient telecommunications is viewed as part of the solution to this set of problems - the means to link a network of epidemiological field stations via satellite with U.S. academic institutions and government agencies, for purposes of research, training in tropical medicine, and observation of and response to epidemic emergencies. At a workshop, telecommunications and technology transfer were addressed and applications of telecommunications technology in long-distance consultation, teaching and disaster relief were demonstrated. Applications in teaching and consultation in tropical infectious diseases is discussed.

Legters, Llewellyn J.↗
NASA NTRS1991

Use of satellite telecommunications for telemedicine

The use of space telecommunications facilities in the interests of medicine should establish a reliable and timely connection between the specialists involved and access for each of them to information sources the need. Since a certain global-scale program should be implemented for this goal to be achieved, one of the top-priority tasks is to determine appropriate orbital facilities for telecommunications as well as appropriate areas and countries for them, outlining the territories where portable data receive/transport records can be placed and stations that are cheap and simple enough to operate can be stored. Eventually the satellite telecommunications system should encourage health workers to unite in a world community on the basis of a regular and efficient information exchange with the goal of protecting the health of man and the peace of Earth. This goal could only be achieved by gradually removing differences in the domain of medical education and information in different regions over the globe, by providing a possibility of rapid and coordinated access to the information on medical problems of interest on the global scale, as well as by coordinating the discussion and solution of all problems associated with the development and progress of the satellite communications system.

Tamkovich, Gennady↗
NASA NTRS1996

The Telecommunications and Data Acquisition Report

This quarterly publication provides archival reports on developments in programs managed by JPL's Telecommunications and Mission Operations Directorate (TMOD), which now includes the former Telecommunications and Data Acquisition (TDA) Office. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC). TMOD also performs work funded by other NASA program offices through and with the cooperation of OSC. The first of these is the Orbital Debris Radar Program funded by the Office of Space Systems Development. It exists at Goldstone only and makes use of the planetary radar capability when the antennas are configured as science instruments making direct observations of the planets, their satellites, and asteroids of our solar system. The Office of Space Sciences funds the data reduction and science analyses of data obtained by the Goldstone Solar System Radar. The antennas at all three complexes are also configured for radio astronomy research and, as such, conduct experiments funded by the National Science Foundation in the U.S. and other agencies at the overseas complexes. These experiments are either in microwave spectroscopy or very long baseline interferometry. Finally, tasks funded under the JPL Director's Discretionary Fund and the Caltech President's Fund that involve TMOD are included. This and each succeeding issue of 'The Telecommunications and Data Acquisition Progress Report' will present material in some, but not necessarily all, of the aforementioned programs.

Yuen, Joseph H.↗
NASA NTRS2000

A New Generation of Telecommunications for Mars: The Reconfigurable Software Radio

Telecommunications is a critical component for any mission at Mars as it is an enabling function that provides connectivity back to Earth and provides a means for conducting science. New developments in telecommunications, specifically in software - configurable radios, expand the possible approaches for science missions at Mars. These radios provide a flexible and re-configurable platform that can evolve with the mission and that provide an integrated approach to communications and science data processing. Deep space telecommunication faces challenges not normally faced by terrestrial and near-earth communications. Radiation, thermal, highly constrained mass, volume, packaging and reliability all are significant issues. Additionally, once the spacecraft leaves earth, there is no way to go out and upgrade or replace radio components. The reconfigurable software radio is an effort to provide not only a product that is immediately usable in the harsh space environment but also to develop a radio that will stay current as the years pass and technologies evolve.

Adams, J.↗
NASA NTRS2004

Analyzing Spacecraft Telecommunication Systems

Multi-Mission Telecom Analysis Tool (MMTAT) is a C-language computer program for analyzing proposed spacecraft telecommunication systems. MMTAT utilizes parameterized input and computational models that can be run on standard desktop computers to perform fast and accurate analyses of telecommunication links. MMTAT is easy to use and can easily be integrated with other software applications and run as part of almost any computational simulation. It is distributed as either a stand-alone application program with a graphical user interface or a linkable library with a well-defined set of application programming interface (API) calls. As a stand-alone program, MMTAT provides both textual and graphical output. The graphs make it possible to understand, quickly and easily, how telecommunication performance varies with variations in input parameters. A delimited text file that can be read by any spreadsheet program is generated at the end of each run. The API in the linkable-library form of MMTAT enables the user to control simulation software and to change parameters during a simulation run. Results can be retrieved either at the end of a run or by use of a function call at any time step.

Kordon, Mark↗
NASA NTRS2016

Small Aerostationary Telecommunications Orbiter Concept for Mars in the 2020s

Current Mars science orbiters carry UHF proximity payloads to provide limited access and data services to landers and rovers on Mars surface. In the era of human spaceflight to Mars, very high rate and reliable relay services will be needed to serve a large number of supporting vehicles, habitats, and orbiters, as well as astronaut EVAs. These will likely be provided by a robust network of orbiting assets in very high orbits, such as areostationary orbits. In the decade leading to that era, telecommunications orbits can be operated at areostationary orbit that can support a significant population of robotic precursor missions and build the network capabilities needed for the human spaceflight era. Telecommunications orbiters of modest size and cost, delivered by Solar Electric Propulsion to areostationary orbit, can provide continuous access at very high data rates to users on the surface and in Mars orbit.In the era of human spaceflight to Mars very high rate andreliable relay services will be needed to serve a largenumber of supporting vehicles, habitats, and orbiters, aswell as astronaut EVAs. These could be provided by arobust network of orbiting assets in very high orbits. In thedecade leading to that era, telecommunications orbiterscould be operated at areostationary orbit that could support asignificant population of robotic precursor missions andbuild the network capabilities needed for the humanspaceflight era. These orbiters could demonstrate thecapabilities and services needed for the future but withoutthe high bandwidth and high reliability requirements neededfor human spaceflight.Telecommunications orbiters of modest size and cost,delivered by Solar Electric Propulsion to areostationaryorbit, could provide continuous access at very high datarates to users on the surface and in Mars orbit. Twoexamples highlighting the wide variety of orbiter deliveryand configuration options were shown that could providehigh-performance service to users.

Lock, Robert E.↗
NASA NTRS2003

Telecommunications systems evolution for Mars exploration

This paper describes the evolution of telecommunication systems at Mars. It reviews the telecommunications capabilities, technology and limiting factors of current and planned Mars orbiters from Mars Global Surveyor to the planned Mars Telecommunications Orbiter (MTO)

Franklin, Stephen F.↗
NASA NTRS1997

(abstract) The Galileo Spacecraft: A Telecommunications Legacy for Future Space Flight

The Galileo mission to Jupiter has implemented a wide range of telecommunication improvements in response to the loss of its high gain antenna. While necessity dictated the use of these new techniques for Galileo, now that they have been proven in flight, they are available for use on future deep space missions. This telecommunications legacy of Galileo will aid in our ability to conduct a meaningful exploration of the solar system, and beyond, at a reasonable cost.

Galileo telecommunications Deep Space Network↗
NASA NTRS1997

The Galileo Spacecraft: A Telecommunications Legacy for Future Space Flight

The Galileo mission to Jupiter has implemented a wide range of telecommunication inprovements in response to the loss of its high gain antenna. While necessity dictated the use of these new techniques for Galileo, now that they have been proven in flight, they are available for use on future deep space missions. This telecommunications legacy of Galileo will aid in our ability to conduct a meaningful exploration of the solar system, and beyond, at a reasonable cost.

Galileo telecommunications Deep Space Network↗
NASA NTRS2003

An evolving Mars telecommunications network to enable exploration and increase science data return

The coming decade of Mars exploration involves a variety of unique telecommunications challenges. Increasing spatial and spectral resolution of in situ science instruments drive the need for increased bandwidth. At the same time, many innovative and low-cost in situ mission concepts are enabled by energy-efficient relay communications. In response to these needs, the Mars Exploration Program has established a plan for an evolving orbital infrastructure that can provide enhancing and enabling telecommunications services to future Mars missions. We will present the evolving capabilities of this network over the coming decade in terms of specific quantitative metrics such as data volume per sol and required lander energy per Gb of returned data for representative classes of Mars exploration spacecraft.

Mars Telecommunication↗
NASA NTRS2006

The Mars Telecommunications Orbiter a key asset in the Mars Network

The Mars Telecommunications Orbiter (MTO) to be launched in 2009 will play a key role in the Mars Network since it will be the first interplanetary mission whose primary objective is to provide communications to existing and upcoming Mars missions, This paper presents a basic description of the primary mission an provides trajectory information for the Mars Telecommunication Orbiter.

Mars Telecommunications Orbiter (MTO)↗
NASA NTRS1994

Small Deep Space Mission Telecommunications

Unique requirements imposed on deep space telecommunications, such as operation at extreme ranges, have historically led to high cost, one-of-a-kind spacecraft telecommunications systems. Yet future deep space misssions must fit within severe cost, mass and power constraints. JPL recently completed a study to find ways of reducing telecommunicaitons cost for future deep space missions. They identified and evaluated alternative telecommunicaitons systems architectures capable of satisfying these needs and design constraints. Future missions are expected to occur more frequently than in the past. The study recommends that a standard deep space transponder be developed. It also recommends spacecraft power amplifier and antenna development efforts.

telecommunications↗
NASA NTRS1972

Telecommunications Systems Design Techniques Handbook

The Deep Space Network (DSN) increasingly supports deep space missions sponsored and managed by organizations without long experience in DSN design and operation. The document is intended as a textbook for those DSN users inexperienced in the design and specification of a DSN-compatible spacecraft telecommunications system. For experienced DSN users, the document provides a reference source of telecommunication information which summarizes knowledge previously available only in a multitude of sources. Extensive references are quoted for those who wish to explore specific areas more deeply.

Edelson, R. E.↗