PRONAOS Ground Control Center: First Operational Ada Application in C.N.E.S

The computer team of the French PRONAOS project decided in 1990 to develop its whole ground control center software in Ada on PC calculators, thus becoming the first operational Ada application in C.N.E.S. After a brief description of the project, this paper will explain the reasons of Ada choice, then describe environment, architecture and main design features of the application software. Then, it discusses the methodological frame of this software development and, as a conclusion, draws the lessons of this experience.