Software quality assurance of cryocooler drive electronics software used in spacecraft

Software plays an important role in the ISRO space mission. Reliability of this software is vital to achieve zero defects in space systems and services. There are varieties of software used in realization of spacecraft. Mainly it is categorized into onboard, mission and ground software. Evaluation of this software is the major activity for a software quality assurance person. Software quality engineer has to certify the software based on system level requirements, mission requirements and functional requirements. All the hardware and software interactions also have to be verified. Risk management is the key factor for effective software management. Software life cycle activities are carried out based on ISRO software process document. Following these standards and guidelines helps to find the defects in the earlier phase of software development life cycle. This paper mainly describes the software quality assurance activities carried out for control drive electronics unit used in GSAT spacecraft. SQA activities complied against the IEEE12207 standards (ISPD-2) at ISRO level. Pulse Tube Cryocoolers are active cryogenic devices used to generate cryogenic temperatures in the 50K-80K range in a single stage. Cryocooler drive electronics unit generates identical drive to both the compressors of pulse tube cryocooler.