Page 213 - Intro to Space Sciences Spacecraft Applications

Introduction to Space Scieplces and Spacecraft Applications
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Figure 9-1. Systems approach. A structured approach is used in the design
of complex systems such as spacecraft.

into a number of phases through which the designer conducts the distinct
steps of the systems approach.
The initial period in the life cycle is the planning period. During this
period, the need for the system is established, system concepts are formu-
lated, and their feasibility and worth are established. The output of the
planning period is an identification of a system concept and a set of sys-
tem requirements. The acquisition period includes those steps necessary
to design, test, and evaluate the system, and to produce and install it, The
use period consists of those activities and resources required to operate,
support and maintain the system.
The phases associated with the planning period consist of the concepru-
al study phase and the mission analysis phase. The acquisition period starts
with the system definition phase and ends with the system development
phase which includes launch and initiation of operation. Within these two
periods, the activities associated with systems engineering are defined. It is
during these periods that maximum benefit may be realized in following
the design process of the systems approach. As shown in Figure 9- 1, these
are mainly applicable to the planning phases and the phases concerned