Spacecraft Attitude and Orbit Determination from the Cost and Reliability Viewpoint: A Review

Spacecraft attitude and orbit control subsystem (AOCS) is responsible for about 30% of the failures of spacecraft. Spacecraft Attitude and orbit determination (SAOD) are two main tasks which are executed by an AOCS. For some spacecraft missions, mission success criterion is related directly to the performance of AOCS. A typical SAOD process is composed from software and hardware. SAOD software has many functions such as management of normal and abnormal operation, in addition to state estimation. SAOD hardware is composed from various sensors, processors, and peripherals. Thus, calculating and increasing the reliability of these interconnected components is a real challenge taking into account the constraints associated with AOCS design. These constraints contain and not limited to high reliability, limited processing power, overall subsystem mass, overall subsystem cost, and limited electric power capabilities. Thus, to increase system reliability against failures, subsystem cost should be carefully considered and minimized. The current article reviews the methods of SAOD in addition to reliability and cost associated with it. Keywords – Spacecraft, Attitude, Orbit, Cost, reliability.