- This paper seeks to provide a brief overview of the somewhat unfamiliar concept underlying system identification, especially as it applies to large flexible space structures. Having elaborated on the concept, the writers provide a detailed description of the identification process including model development, its experimental validation, and final certification. This is followed by a classification of the different identification methods and a brief evaluation of the potential of existing methodology to address special circumstances of large flexible space structures. This overview seeks to draw attention to the fact that existing methodology in system identification may not be adequate to solve many of the identification problems implicit in the next generation of orbital missions. Hence substantial research is needed to extend these existing methods to better address the special circumstances of large flexible space structures. ASCE.