Product Assurance for the Development of the Sax AOCS Application Software

摘要

The Italian/Dutch SAX satellite, to be launched end of April 1996, is ascientific spacecraft, built to explore celestial X-ray sources. The software for the Attitude and Orbit Control Subsystem on-board computer for SAX consists of special purpose Basic Software, which performs operating system functions, and of Application Software (ASW). The ASW has been developed by NLR, under contract with Fokker Space. Main goal of the application software is to ensure an accurate and stable pointing of the satellite's main axis during periods of up to 28 hours. Due to the mission critical nature of the ASW, which shall be able to operate during extended periods without ground contact, it has to be very reliable. This software has been developed in two phases. The differences in PA during the full scale development phase and the maintenance phase are compared, leading to a number of quantitative and qualitative conclusions.