Engineering Papers⌕ Search

Engineering topics

Garrison, G. W.

Publications and source records attributed to Garrison, G. W..

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Electric Propulsion Orbital Platform

This paper describes the Electric Propulsion Orbital Platform (EPOP), of which the primary objective is to provide an instrumented platform for testing electric propulsion devices in space. It is anticipated that the first flight, EPOP-1, will take place on the Shuttle-deployed Wake Shield Facility in 1996, and will be designed around a commercial 1.8 kW arcjet system which will be operated on gaseous hydrogen propellant. Specific subsystems are described, including the arcjet system, the propellant and power systems, and the diagnostics systems.

Friedly, V. J.↗
NASA NTRS1992

EPOP - Toward the realization of an Electric Propulsion Orbital Platform

This paper describes the results of a feasibility study for an Electric Propulsion Orbital Platform (EPOP), whose primary objective is to provide an instrumented platform for testing electric propulsion devices in space. It is anticipated that the first flight, EPO-1, will take place on the Shuttle-deployed Wake Shield Facility in 1996, and will be designed around a modified version of a commercial 1.8 kW hydrazine arcjet system, to be operated on gaseous hydrogen propellant. Specific subsystems are described, including the arcjet system, the propellant and power systems, and the diagnostics systems. Also, system engineering and integration issues are discussed.

Friedly, V. J.↗
NASA NTRS1979

Voyager telecommunications - The broadcast from Jupiter

The means by which the data collected by the Voyager 1 mission to Jupiter were returned to earth are presented. Radio links between the earth and the spacecraft are used for the transmission of both imaging and nonimaging telemetry from the spacecraft and commands from the earth and for radiometric observations of the spacecraft and its environment. Features which have lead to vast improvements in the capability of the Voyager telecommunications system over that of previous space probes include the use of X-band rather than S-band telemetry, a dual power X-band traveling wave tube amplifier, a 3.7 m spacecraft antenna and a single channel telemetry system with concatenated coding. Communications equipment at the three ground complexes of the Deep Space Network for telemetry reception includes 64 m steerable antennas, cryogenic maser preamplifiers and a phase-lock loop receiver. Voyager 1 has met or exceeded all of its telecommunications requirements, providing a 98% data return and a total of 2 x 10 to the 11th data bits during the Jupiter encounter.

Edelson, R. E.↗
NASA NTRS1975

National law enforcement telecommunications network

Alternative approaches are analyzed to a National Law Enforcement Telecommunications Network (NALECOM) designed to service all state-to-state and state-to-national criminal justice communications traffic needs in the United States. Network topology options were analyzed, and equipment and personnel requirements for each option were defined in accordance with NALECOM functional specifications and design guidelines. Evaluation criteria were developed and applied to each of the options leading to specific conclusions. Detailed treatments of methods for determining traffic requirements, communication line costs, switcher configurations and costs, microwave costs, satellite system configurations and costs, facilities, operations and engineering costs, network delay analysis and network availability analysis are presented. It is concluded that a single regional switcher configuration is the optimum choice based on cost and technical factors. A two-region configuration is competitive. Multiple-region configurations are less competitive due to increasing costs without attending benefits.

Reilly, N. B.↗
NASA NTRS1975

Telecommunications systems design techniques handbook

Handbook presents design and analysis of tracking, telemetry, and command functions utilized in these systems with particular emphasis on deep-space telecommunications. Antenna requirements are also discussed. Handbook provides number of tables outlining various performance criteria. Block diagrams and performance charts are also presented.

Edelson, R. E.↗