Dynamic spatial ability is one's ability to estimate when a moving object will reach a destination, or one's skill in making time-to-contact (TTC) judgments. In 2 studies, we investigated the nature of dynamic spatial ability and its role in psychomotor (PM) task performance. In the first study, 405 basic military trainees were given both spatial and nonspatial versions of TTC and comparative arrival-time tasks, and we found that the spatial and nonspatial versions of the tasks were more highly correlated than the spatial tasks were to each other, suggesting that a timing, rather than a spatial, mechanism underlies performance of dynamic spatial tasks. In the second study with 376 military trainees, we found that performance on a set of PM tasks was predicted by a general working-memory (WM) Capacity factor (r = 0.45) and an orthogonal Temporal Processing (TP) factor (r = 0.55), suggesting the importance of the dynamic spatial, or of the TP factor, in many real-world activities.