Approach to transaction management for Space Station Freedom

The Space Station Freedom will consist of many systems providing operational support to many user payloads and other Space Station Freedom systems. Some of the operations of the systems and payloads may be potentially hazardous to the space station or its systems or crew. Other operations will require resources and may require stringent environmental conditions for successful conduct. Some operations may disturb the operating environment for other systems and payloads, such that their environmental requirements are not met. Provision for any of these operating requirements is conditioned on other operations and the status of the space station and its systems. That is, determining whether any operation is permissible or should be permitted at any time depends on the status of the space station and the other operations in progress. This paper describes an approach to managing the operations based on their external effects. The approach presumes that there is a conflict free schedule that, if followed, will allow only appropriate operations to occur. The problem then reduces to assuring that operations initiated are within the latitude allowed by the schedule. More simply, the approach ensures that the external effects of such operations are within those allowed by the schedule. This paper describes the currently preferred space station transaction management approach. However, as operations requirements and concepts evolve, the program may alter this approach.