This paper describes cooperative work in real-time flight operations in the SAMPEX Mission Operations Room at NASA Goddard Space Flight Center. This domain is an example of distributed supervisory control, where a team of human operators supervises a dynamic, complex, highly automated system. Such operational environments differ in important ways from artifact-centered collaboration (e.g., collaborative drawing, writing, design). This paper explores those differences and also articulates the need for activity management tools for dynamic control environments. Candidate models from the human-machine systems engineering literature are proposed to provide the underlying structure for such tools.