In this paper two case studies of model validation and verification of large and complex space structures are presented. The first case study focuses on experience gained in performing model validat~on and verification of the mated Russian Mir Space Station and United States Space Shuttle. This study makes use of dynamic test data taken during the STS-81 flight associated with the Mir Structural Dynamics Experiment. The second case study involves the International Space Station P6 truss segment tested in the launch configuration. In both cases, a newly developed capability within UAIINASTRAN is used to perform the model validation and verification. Key technical issues raised in these studies provide useful insight for future pretest planning and model validation and verification efforts.