The Space Mission Life Cycle

Table 1-2 illustrates the life cycle of a space mission, which typically progresses through four phases:

• Concept exploration, the initial study phase, which results in a broad definition of the space mission and its components.

• Detailed development, the formal design phase, which results in a detailed definition of the system components and, in larger programs, development of test hardware or software.

• Production and deployment, the construction of the ground and flight hardware and software and launch of the first full constellation of satellites.

• Operations and support, the day-to-day operation of the space system, its maintenance and support, and finally its deorbit or recovery at the end of the mission life.

These phases may be divided and named differently depending on whether the sponsor—the group which provides and controls the program budget—is DoD, NASA, one of the many international organizations, or a commercial enterprise. The time required to progress from initial concept to deorbiting or death of the space asset appears to be independent of the sponsor. Large, complex space missions typically require 10 to IS years to develop and operate from 5 to 15 years, whereas small, relatively simple missions require as few as 12 to 18 months to develop and operate for 6 months to several years.

Procurement and operating policies and procedures vary with the sponsoring organization, but the key players are the same: the space mission operator, end user or customer, and developer. Commercial space missions are customer driven. The main difference between users and customers is that customers usually pay for a service, whereas users receive services that others pay for. Operators control and maintain the space and ground assets, and are typically applied engineering organizations. End users receive and use the products and capability of the space mission. They include astronomers and physicists for science missions, meteorologists for weather missions, you and me for communication and navigation missions, geologists and agronomists for Earth resources missions, and the war fighter for offensive and defensive military

TABLE 1-2. Space Program Development Phases. Every space program progresses through the top-level phases. Subphases may or may not be part of a given program. The time required to complete the process varies with the scope. (Diagram courtesy R. Bertram).)
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