Upgrading unmanned spacecraft quality and reliability through environmental testing.
Reliability in unmanned spacecraft by environmental testing, specifically of Ariel I, Echo II and Relay I
UNMANNED SPACECRAFT↗
SEARCH · Engineering Papers
Results for “Relays”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Seismometer designed for remote operation in random orientation
Portable seismometer mounted in a rugged housing can be placed in inaccessible locations and operate efficiently in other than a vertically upright position. The instrument housing contains an amplifier, transmitter, and antenna to relay measurement data to a receiving station.
Lehner, F. E.↗
Solid-state switch increases switching speed
Solid state switch for commutating capacitors in an RC commutated network increases switching speed and extends the filtering or commutating frequency spectrum well into the kilocycle region. The switch is equivalent to the standard double- pole double-throw /DPDT/ relay and is driven from digital micrologic circuits.
Mc~gowan, G. F.↗
A system for automatic accumulation of radiation data
Digital clock, scanner, and relay box for system for automatic accumulation of radiation data on semiconductor devices
DIGITAL TECHNIQUE↗
Magnetic shielding of spacecraft hardware
Magnetic shielding of spacecraft relays and switches
MAGNETIC SHIELDING↗
A feasibility study of a communications satellite for deep-space monitoring
Use of earth orbiting satellite as communications relay between earth and space vehicles on interplanetary missions
SPACE VEHICLE↗
GEOS command assignment
Satellite operational reliability by assigning command functions to relay matrix positions of command subsystem
SATELLITE COMMUNICATION↗
Communications in space.
Book on communications satellites design, testing, operation and power systems for Echo, Telstar, Relay, Syncom, ground stations, etc
COMMUNICATIONS SATELLITE↗
Improved fluid control circuit operates on low power input
Standard electromagnetic relay actuates fluid control circuits with low level electrical signals by switching a fluid amplifier that drives a spool valve.
Gebben, V.↗
Hybrid solid state switch replaces motor- driven power switch
Hybrid solid state switch replaces existing motor-driven power switches used on spacecraft. It uses a transistor circuit to limit the open circuit voltage and allow small relay contacts to handle high transient currents at reasonable cycle life.
Booth, R. A.↗
SiC/Si diode trigger circuit provides automatic range switching for log amplifier
SiC/Si diode pair provides automatic range change to extend the operating range of a logarithmic amplifier-conversion circuit and assures stability at or near the range switch-over point. the diode provides hysteresis for a trigger circuit that actuates a relay at the desired range extension point.
Source record↗
Continuous wave detector has wide frequency range
Portable battery-operated detector indicates the presence of steady state signals exceeding a predetermined value over a wide frequency range by the closure of output relay contacts. It was designed to monitor electronic equipment used in the Saturn 2 program.
Deutsch, W. F.↗
The Post Office communication system ground station at Goonhilly, Cornwall
The initial purpose of the Post Office satellite system earth station at Goonhilly Downs, Cornwall, is to obtain information on the performance of experimental communication satellite systems; such information will be of great importance to the designers of systems for commercial operation. To facilitate this dissemination the UK and USA Governments prepared and signed, in February 1961, a Memorandum of Understanding regarding collaboration between the British Post Office and the United States National Aeronautics and Space Administration (NASA) on the testing of experimental communication satellites to be launched by NASA. The first phase of the tests covered Projects Telstar and Relay, both active satellites.
COMMUNICATIONS SATELLITE↗
The Goonhilly 85-ft. steerable dish aerial
The choice of the basic type of aerial for a satellite communication ground station is of major importance in view of its influence on the overall performance, cost and time to complete the installation. In the case of the Post Office satellite communication earth station at Goonhilly Downs, Cornwall, a decision was made early in 1961 to use an 85-ft diameter steerable paraboloidal dish aerial, without a radome for tests with the Telstar and Relay, and other communication satellites. Tests with smaller paraboloidal dish aerials with the feed in the aperture plane had shown that a satisfactory electrical performance could be obtained, and experience with the 250-ft diameter radio telescope at Jodrell Bank had shown that the mechanical problems could be overcome. An important factor in the present case was the limited time--less than one year--available for the design, manufacture, construction and testing of the aerial.
COMMUNICATIONS SATELLITE↗
Computing and data transmission for the prediction steering of the Goonhilly satellite-communication aerial
The Goonhilly satellite-communication aerial uses an 85-ft. diameter paraboloidal reflector with waveguide feed at the focus. The aerial is movable in azimuth and elevation, and is provided with independent feedback control systems for these two motions. During a satellite pass, the aerial must be steered so that its axis points continuously, and with high accuracy, in the direction of the satellite. Of the various possible methods of achieving this result, that based on prediction of satellite position has been adopted for the first transatlantic communication experiments using the Telstar and Relay satellites. The process by which orbital predictions originating in the USA are converted to substantially continuous real-time azimuth and elevation pointing instructions at Goonhilly is described herein.
GROUND STATION↗
Waveguide feeder system for the Goonhilly satellite-communication earth station
There are two features which distinguish the feeder arrangements at a satellite earth station from those used in conventional microwave line-of-sight links. The first is the importance of low loss in all waveguides and components and the second is the need for rotating joints. Losses are important in the receive direction because they contribute significantly to the overall system noise temperature while, in the transmit direction, not only do they waste expensive transmitter power but localized points of high loss can give rise to the formation of arcs when the power is applied. Rotating joints are required on the elevation axis of the aerial to permit waveguide connection between apparatus in the turntable cabin and on the dish. In the installation at Goonhilly, three separate waveguide connections are required between the turntable cabin and the focus platform; one each for the Telstar and Relay transmitters operating at 6390 and 1725 Mc/s respectively, and one for the receiver feed, routed via the maser cabin on the back of the dish and operating at 4170 and 4080 Mc/s. Dominate-mode rectangular waveguide is used for these runs, and the components and installation practices used follow normal practice as far as possible.
GROUND STATION↗
Demodulation techniques for use at Goonhilly satellite-communication earth station
As part of the programme of experimental and development work to determine the optimum demodulating techniques for communication satellite systems, three types of demodulators have been investigated at the Goonhilly earth station: 1.A conventional demodulator of the type used in 960-channel telephony or television microwave radio-relay links; 2.A frequency modulation feed-back demodulator in which the deviation of the signal is reduced before it reaches the final discriminator; and 3.A variable-bandwidth 'dynamic-tracking' demodulator in which the resonant frequency of a narrow bandwidth tuned circuit is moved rapidly to follow the nominal instantaneous frequency of the incoming signal. The conventional demodulator will not be discussed in detail here;. however, information is given on two specialized demodulators.
COMMUNICATIONS SATELLITE↗