58. Lesson: Software Development
Software development should receive the same attention and rigor as hardware development. Ground software should not be an exception. Milestones should be established and tracked with critical attention.
Space missions are just as dependent upon timely and successful development of software as upon hardware. It is traditionally difficult to establish firm milestones which are definable and definite, and there is, therefore, generally less understanding and visibility in the status and progress of this less understood element.
The launch of Skylab was almost delayed due to the status of the mission control center software. The basic programs were available but many of the auxiliary programs were not operable. A major effort was made on the last weeks preceding the launch to speed up the software development, but on launch day, two programs were still inoperable.
The maturity of the development (i.e., the nearness to completion) is difficult to assess using only the traditional approach of measuring the number of hours of test. One reasonable measure is the number of program open anomalies or program notes, which define computing situations which should be avoided.
These lessons learned are from SKYLAB LESSONS LEARNED AS APPLICABLE TO A LARGE SPACE STATION, A dissertation submitted to the faculty of The School of Engineering and Architecture Of the Catholic University of America For the Degree Doctor of Engineering by William C. Schneider, Washington, D.C., 1976.
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