Communication satellites

Beryllium is used as an alloying agent in producing beryllium copper, which is extensively used for springs, electrical contacts, spot-welding electrodes, and non-sparking tools. It is applied as a structural material for high-speed aircraft, missiles, spacecraft, and communication satellites. Other uses include windshield frame, brake discs, support beams, and other structural components of the space shuttle. 

Nickel-Hydrogen, Nickel-Iron, and Nickel-Metal Hydride. First developed for communication satellites in the early 1970s, nickel-hydrogen batteries are durable, require low maintenance, and have a long life expectancy. The major disadvantage is the high initial cost. For these batteries to be a viable option for electric vehicles, mass production techniques will have to be developed to reduce the cost. 

The first experiments with the thermal electric engine were conducted in Russia in 1929 by its inventor, Valentin P. Glushko, who later became a world-famous authority in rocket propulsion. For more than forty years, the United States and Russia have devoted many resources to research and development of various kinds of EREs. First tested in space by the Russians in 1964, these engines have found some limited applications in modern space technology. For more than two decades Russian weather and communication satellites have regularly used electric rocket engines for orbital stabilization. The first spacecraft to employ ERE for main propulsion was the American asteroid exploration probe Deep Space 1, launched in 1998. The performance of... 

A small fire in a computer room, a telephone exchange, or an assembly plant for communication satellites can cause enormous damage because of minute amounts of corrosion on circuit elements. Furthermore, if either water or a halogenated agent is used to control the... 

The effects of the radiation flux in space on polymer materials is now of considerable importance due to the increasing use of communications satellites. Geosynchronous orbit corresponds to the second Van Allen belt of radiation, which comprises mainly electrons and protons of high energy. 

Communication Satellites. The next example illustrates an expert system similar to those under development in process control and instrumentation companies. These systems are designed to diagnose faults and suggest corrective actions. 

Subsequently, basic scientific research made great contributions to our nation s economic strength and its security. Some wonderful examples are described in a series of publications called Beyond Discovery The Path from Research to Human Benefit produced by the National Academies. Each brochnre chronicles some discovery in basic science and how it has had applications beyond what anybody could have imagined. Often as a side benefit, many new products emerged from federal government support (for example, communications satellites) and a series of new discoveries was made. 

In the Cold War there were also some specific needs that energized basic research. For example, prior to communications satellites, using the ionosphere to reflect radio waves was the only way to communicate around the world at the... 

CODASYL—See Conference on Data Systems Languages Communications and network, 37-44 Communications satellite, 41 Computer... 

It was asked what velocity and height must a satellite have so that it remains stationary above the same point on Earth s surface that is, have the same rotation period, one day, as the earth. Three such satellites, placed 120 degrees apart around the earth, could make instantaneous communication with all points on the earth s surface possible. From the fact that period squared is proportional to the cube of the radius and the above periods of the moon and satellite and the moon s distance, it is found that the communication satellite would have to be located 26,000 mi from earth s center or 22,000 mi above the surface. Its velocity must be about 6,800 MPH. Many such satellites are now in space around the earth. 

Hydrazine has been studied extensively for use in monopropellant thrusters for space flights of long duration. Thrusters are used or altitude control of communication satellites. Here the decomposition of hydrazine over a packed bed of alumina-supported iridium catalyst is of interest. " In a proposed study, a 2% hydrazine in 98% helium mixture is to be passed over a packed bed of cylindrical particles 0.25 cm in diameter and 0.5 cm in length at a gas-phase velocity of 15m/s and a temperature of 750 K. The kinematic viscosity of helium at this temperature is 4.5 X 10 nF/s. The hydrazine decomposition reaction is believed to be externally mass transfer-limited under these conditions. If the packed bed is 0.05 m in length, what conversion can be expected Assume isothermal operation. 

Secondary batteries Portable electronic devices cell phones, cordless phones, laptops, camcorders, toys. Communications satellites, military radios. Transportation electric vehicles, car ignition batteries. Defense torpedoes, missiles. 

Launch systems Communication Satellites Spacecraft Space shuttle... 

Major polymer applications surface protective coatings (protective and decorative - automotive, metal cans, industrial flooring, anticorrosive paints), electrical/elec-tronics (printed circuit panels, conductive adhesives), composites (building/construction, marine, electrical/electronics, aircraft, communication satellites, automotive, pipes, consumer products), bonding and adhesives, flooring, tooling and casting, biosensors... 

Other well known productive programs outside the chemical area are the miniaturization of solid state electronics and the communications satellites, both with NASA. 

Hydrazine has been studied extensively for use in monopropellani thrusters for space flights of long duration. Thrusters are used for altitude control of communication satellites. Here the decomposition of hydrazine over a packed bed of alumina-supported... 

The nickel-cadmium battery (Ni-Cd) is the most common battery used in communication satellites, in Earth orbiters, and in space probes. The chemical reactions are ... 

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