CCL: A test language for automating spacecraft checkout operations

Every Complex Spacecraft undergoes rigorous testing of 3 to 6 months before being declared ready for launch. The satellite integration and testing activities are an important milestone in the realization of any spacecraft. The time and effort required to completely test any spacecraft is enormous and any means of reducing the time and effort and still delivering a fully tested fault free spacecraft is a very challenging job. The only way to achieve this is by improving automation efforts in this phase of spacecraft building. The in-house designed and developed Checkout Command Language (CCL) helps in preparing the test schedules and test procedure files well in advance, reduces the manpower requirements and minimizes testing time. CCL is a powerful procedure language for complete automation of test environment. CCL is Simple, English like, easy to learn and provides all the necessary instruction required for testing a spacecraft. The 50 odd instructions provide means to send telecommands to spacecraft, check the telemetry, instructions for test equipment monitoring and Control. CCL also provides means to call another test procedure file. With the help of CCL procedures once written can be executed many times, thus ensuring repetivity of tests. These procedures written can be executed either in Automode or single step mode or interactive mode depending on the operator/test need. CCL compiler will check for the syntax of the test procedure before execution. An interpreter for CCL is developed which is used for executing the test procedures written using CCL. Interpreter has additional features like linking the files, proving statistical information about the tests which help in improving automation. This paper will present in detail the features of CCL and the feedback from the users and the improvements planned in future.