Solar array power communication

FIGURE 9-14 Solar array power communication satellites. 

The solar-array output power is reduced after each year of operation in space regardless of satellite category. To explain the solar-array power degradation, the output power of the solar array for a communications satellite with operational life of seven years is assumed to be 650 W in the beginning of the first year of operation. This power output is reduced to 610 W after one year of operation, to 570 W after two years of operation, to 548 W after three years of operation, to 525 W after four years of operation, to 510 W after five years of operation, to 480 W after six years of operation, and finally to 450 W after seven years of operation. 

Following launch the first set of mechanisms operated are those involved in the deployment of antennae, booms, solar arrays etc. Deployment normally occurs very soon afim launch to ensure that communication and power are established as rapidly as possible. These are invariably one-shot devices, which may have been tested in excess of 50 times before launch. Key features are the separation of latches, launch locks and clamped interfaces without adhesion. Mechanisms range from simple springs to pin-pullers, memory alloy elements, cable cutters, thermal knives, powered hinges, DC motor gearheads, dampers of various types etc. 

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