We describe the development of the Spaceport Throughput Analysis Resource (STAR), which evaluates Kennedy Space Center spaceport launch throughput. STAR integrates simulation and limited rescheduling, using a constraint programming model to check constraints and reschedule events. The outputs of STAR are launch delays, and the constraint violations leading to those delays, that can be used to inform infrastructure investments to reduce future delays. At STAR's core is a constraint program representing a limited horizon scheduling problem used to identify resource constraint violations, and revise schedules in the presence of unexpected events that disrupt the launch schedule. We describe the design and implementation of STAR using illustrative examples, and describe performance results on use cases showing how increased launch rates stress KSC infrastructure.