ISS Launch to Activation EVA Cooperative Design

The design challenges presented by the late evolving International Space Station (ISS) Launch to Activation (LTA) thermal concerns required concerted effort and tradeoffs to be made between affected subsystems. The resulting design and mission planning modifications were made with consideration of thermal, electrical power system and extravehicular activity impacts in mind. It was an excellent exercise in cooperative problem solving that allowed each subsystem visibility into potential impacts of their efforts on other related systems and therefore work towards balanced solutions. It was also an excellent exercise in preparing these subsystems for future quick response cooperative problem solving that will be required to support ISS during its lifetime. The author and co-authors were the Boeing Extravehicular Activity (EVA), Electrical Power Systems (EPS) and Thermal Subsystem representatives in a Launch to Activation Tiger Team effort, which was conducted at the Johnson Space Center in 1996. The primary focus was the near term assembly flights AF2A-AF5A, as well as AF7A. The Tiger Team approached the analysis and solutions from a global vehicle perspective and sought to optimize each mission to assist the subsequent mission's LTA challenges. This paper will focus on the EVA aspects of the launch to activation resolution, while touching on the thermal and electrical power system inter-related concerns.