TABLE OF CONTENTS System engineering is the comprehensive engineering task in spacecraft design. It makes the subsystems work together and makes the whole greater than the parts. System engineering includes the following major functions: 1) requirements definition, 2) resource allocation and management, especially power and mass, 3) conduct of system level trade studies, for example comparing navigation by ground operations and by onboard navigation, and 4) technical integration of the subsystems into a spacecraft system and integration of the spacecraft with other project elements: launch vehicle, ground systems, etc. In this chapter we will take a top view of a spacecraft and a design project. We will discuss the anatomy of a spacecraft, the resources and margins needed, and the launch vehicle interface. This chapter will follow NASA practice and terminology [1]; however, all government agencies have similar practices.
In this section we will discuss the life cycle of a spacecraft project, the composition of a spacecraft project, and the subsystems of which a spacecraft is made.
A spacecraft is born by stages, as shown in Fig. 2.1. The design activities on a spacecraft vary substantially during the life cycle. The first step is an idea: "I wonder if we couldn't get surface pictures of Venus through the clouds using synthetic aperture techniques?". An idea can originate anywhere in the aerospace community, from a customer, from a university, or from a contractor. Most corporations and customers maintain small organizations with the purpose of...
