This dissertation presents the design, fabrication and testing of a sounding rocket flight computer for the South African Astronomical Observatory (SAAO).
Sounding rockets carry instruments with which to take measurements in the Earth’s atmosphere in sub-orbital flight. The South African Astronomical Observatory (SAAO) requires a flight computer for their sounding rockets. This flight computer is to replace the current commercial flight computer currently in use improving on its functionality and expandability.
Based on SAAO’s requirements a specification has been derived. This specification includes the functions required of the flight computer, the stresses and constraints the flight computer must operate under and the testing procedures to verify the operation of the flight computer. From this specification a modular and extensible flight computer has been designed and implemented. The design included the design of the hardware as well as the design of the operating system and algorithms to run on the flight computer hardware. In order to meet the requirements of SAAO a master-slave architecture was chosen in the design using the Controller Area Network bus.
Once designed the flight computer was prototyped and tested using tests outlined in the specification. The hardware has been taken through three prototyping phases, with each phase bringing the flight computer closer to meeting the specification. Algorithms were prototyped and simulated on a PC in the C language before being ported to embedded C with fixed point arithmetic to run on the hardware. Simulations were carried out with actual flight data obtained from the RDAS mailing list. Also developed was a graphical user interface, using the Qt framework in the C++ language, to interface with the flight computer and to display simulations results.