ABSTRACT
A satellite consists of various systems designed to meet the mission specific requirements. All but the simplest satellites require a common set of systems shown by the solid lines in Figure 1.1. Complex satellites require additional systems shown by the dotted lines. The systems are classified into two groups, the payload and the bus. The payload consists of the communications equipment in commercial satellites or science instruments in research satellites. The bus consists of all remaining equipment grouped into several functional systems that support the payload. The power system is one of the bus systems that consist of the solar array, battery, power electronics, distribution harness, and controls. Other essential bus systems are the communications and data handling system to receive commands and return information, telemetry sensors to gage the satellite state, and a
central computer to coordinate and control activities of all the systems. Satellites with complex missions also require systems to determine the spacecraft attitude and orbit orientation, and propulsion to control both. Satellite design is generally optimized to the fullest extent such that any
change would result in a higher cost. The total mission cost, however, is a complex function of many variables, and so is the power system cost. The cost, C, in dollars per watt of power generated can be expressed as a function of four major variables as follows:
C ¼ fðX1;X2;X3;X4Þ ð1:1Þ
where X1 ¼ cost per kg of the power system mass launched, X2 ¼ cost per liter of the power system volume launched, X3 ¼ cost per watt of the power system generation capacity, and X4 ¼ cost of altitude control related with power system components.
