Engineering topics

Schreur, Barbara

Publications and source records attributed to Schreur, Barbara.

4 records

NASA NTRS1998

Presenting the Shuttle Main Engine Software

Originally, this project was to produce an animated Powerpoint presentation of the 'Shuttle Engine and its Software' and to produce a web page with animation including the same materials but with greater detail in the description of the software. The principal emphasis was to be on the web page. Midway through the first year of the project, we were advised by the technical coordinator of this work at MSFC to concentrate on the web page alone. Also, the project was expanded to include a web presentation of the MRECS (Modular Rocket Control System). For the SSME project, the web page presentation has been completed. The integration of the animation into the web page is complete although we have been asked to speed up the animation. Also, the addition of greater detail to the description of the SSME controller software has been added. Much of the work on this program was done by students as their task for their senior project course, the capstone course of their program of study. The students gained a great deal from this project. They have learned to use VISIO, POWERPOINT, PHOTOSHOP, and several web page software packages. The starting point for this project was a PowerPoint presentation by the PI while on a Summer Faculty Fellowship at MSFC. For this project, about half of the drawings of the SSME were improved and about half were completely redrawn. The original still drawings have been animated to illustrate the fuel flow through the SSME system.

Schreur, Barbara↗

NASA NTRS1996

The shuttle main engine: A first look

Anyone entering the Space Shuttle Main Engine (SSME) team attends a two week course to become familiar with the design and workings of the engine. This course provides intensive coverage of the individual hardware items and their functions. Some individuals, particularly those involved with software maintenance and development, have felt overwhelmed by this volume of material and their lack of a logical framework in which to place it. To provide this logical framework, it was decided that a brief self-taught introduction to the overall operation of the SSME should be designed. To aid the people or new team members with an interest in the software, this new course should also explain the structure and functioning of the controller and its software. This paper presents a description of this presentation.

Schreur, Barbara↗

NASA NTRS1994

Evaluation of the efficiency and reliability of software generated by code generators

There are numerous studies which show that CASE Tools greatly facilitate software development. As a result of these advantages, an increasing amount of software development is done with CASE Tools. As more software engineers become proficient with these tools, their experience and feedback lead to further development with the tools themselves. What has not been widely studied, however, is the reliability and efficiency of the actual code produced by the CASE Tools. This investigation considered these matters. Three segments of code generated by MATRIXx, one of many commercially available CASE Tools, were chosen for analysis: ETOFLIGHT, a portion of the Earth to Orbit Flight software, and ECLSS and PFMC, modules for Environmental Control and Life Support System and Pump Fan Motor Control, respectively.

Schreur, Barbara↗

NASA NTRS1993

Evaluation of the efficiency and fault density of software generated by code generators

Flight computers and flight software are used for GN&C (guidance, navigation, and control), engine controllers, and avionics during missions. The software development requires the generation of a considerable amount of code. The engineers who generate the code make mistakes and the generation of a large body of code with high reliability requires considerable time. Computer-aided software engineering (CASE) tools are available which generates code automatically with inputs through graphical interfaces. These tools are referred to as code generators. In theory, code generators could write highly reliable code quickly and inexpensively. The various code generators offer different levels of reliability checking. Some check only the finished product while some allow checking of individual modules and combined sets of modules as well. Considering NASA's requirement for reliability, an in house manually generated code is needed. Furthermore, automatically generated code is reputed to be as efficient as the best manually generated code when executed. In house verification is warranted.

Schreur, Barbara↗