Space surveillance is the activity of keeping a current catalog of information on manufactured, Earth-bound resident space objects. Some necessary functions to perform this task are search and detection, acquisition and tracking, tasking and scheduling, and data reduction and processing. The Midcourse Space Experiment satellite, launched 24April 1996, carries the Space-Based Visible sensor packagedesigned for conducting space surveillance froma spaceplatform.Other contributionsto this issue discuss Space-BasedVisible operations,data reduction, and accuracy. The Space-Based Visible provides high-accuracy angle measurements (right ascension and declination). Based on these data, space-based space surveillance catalog maintenance can be demonstrated. To this end, orbits are calculated based on ground-based data, space-based data, and various combinations of these data. From these results a number of surveillance functions can be demonstrated, for example, compatibility and fusion of space-based and ground-based metric (position) data. When an independent, high-accuracy orbit is available, an assessment of the orbit accuracy is made. In other cases, differences between the orbits are computed. In addition, access to the complete geosynchronous belt and catalog maintenance for geosynchronous satellites will be demonstrated. Effectiveness of space-based space surveillance data is assessed.