Engineering topics
Publications and source records attributed to Garman, John R..
A series of viewgraphs on computer networks at the Johnson Space Center (JSC) are given. Topics covered include information resource management (IRM) at JSC, the IRM budget by NASA center, networks evolution, networking as a strategic tool, the Information Services Directorate charter, and SSC network requirements, challenges, and status.
Flight data systems' software development is chronicled for the period encompassing NASA's Apollo, Space Shuttle, and (ongoing) Space Station Freedom programs, with attention to the methodologies and 'development tools' employed in each case and their mutual relationships. A dominant concern in all three programs has been the accommodation of software change; it has also been noted that any such long-term program carries the additional challenge of identifying which elements of its software-related 'institutional memory' are most critical, in order to preclude their loss through the retirement, promotion, or transfer of its 'last expert'.
The array of technologies and methodologies involved in the development and integration of avionics software has moved almost as rapidly as computer technology itself. Future avionics systems involve major advances and risks in the following areas: (1) Complexity; (2) Connectivity; (3) Security; (4) Duration; and (5) Software engineering. From an architectural standpoint, the systems will be much more distributed, involve session-based user interfaces, and have the layered architectures typified in the layers of abstraction concepts popular in networking. Typified in the NASA Space Station Freedom will be the highly distributed nature of software development itself. Systems composed of independent components developed in parallel must be bound by rigid standards and interfaces, the clean requirements and specifications. Avionics software provides a challenge in that it can not be flight tested until the first time it literally flies. It is the binding of requirements for such an integration environment into the advances and risks of future avionics systems that form the basis of the presented concept and the basic Integration, Test, and Verification concept within the development and integration life cycle of Space Station Mission and Avionics systems.
The NASA environment is described with attention given to mission data systems in NASA and the strategic view. Space Station data systems are characterized into the following: distributed data systems, functionality and complexity, session oriented user interface, and distributed software development. The concept of a support software environment within the Space Station Program is elucidated and a strategic model for integrated data processing is presented.