CHAPTER 1 SYSTEMS: INTERNATIONAL SPACE STATION PLANNING—A ROADMAP TO GETTING IT ALL DONE 4 per increment are also set aside for the crew to have time off from work. The remaining time is divided between maintenance or assembly activities or “utilization”—the catchphrase for all scientific research. Construction or developmental tasks dominated crew time during the assembly time frame, with little time available for utilization. Utilization time was so short in the early days of the ISS Program that astronauts would often do volunteer science on Saturdays. However, this practice can lead to overly tired crews and, possibly, burnout. By about 2013, 30 hours a week was being carved out for utilization, which is expected to reach more than 70 hours a week around 2018 when the new US commercial crewed vehicles, which can carry four astronauts, become available. Crews are assigned to an increment at about the same time that the IDRD development kicks off. Early in the program, especially during the assembly phase, crew selection was often based on planned activities. For example, astronauts who were skilled in robotics could be assigned to increments where a great deal of robotic work might be needed. Similar assignments could occur for increments heavy in spacewalks. This proved challenging to the flight control team, astronauts, and trainers as schedules frequently shifted, often due to shuttle mission delays. As the ISS evolves, and as planners gain more experience with the ever- changing nature of ISS operations, crews are being provided with generic skill-based training such as preparation for any type of operation. For example, a crew might be trained to perform a spacewalk and change out a generic box instead of learning the specifics of a particular unit. Electrical connectors for all boxes are similar, thus specific instructions can be provided just prior to a specific extravehicular activity (EVA). Now where did I put that? A lot of equipment and supplies go to and return from the ISS. Experiments and food, for example, go up research specimens and broken parts needing repair come down. Imagine keeping track of everything in your house over many years. Now, add in the complexity that occurs when the residents change every 6 months. Every bit of space on the ISS is used for something—e.g., if a system component or an experiment is not in a spot, that spot is probably being used for stowage. ISS Program personnel try to position as much spare parts, food, and water to keep operations going for as long as possible since supply rockets can, and have, failed to deliver precious supplies. Managing where and how to store all the supplies and equipment required to keep the ISS going is literally a full-time job. That job belongs to the Inventory Stowage Officers (ISOs) in Houston, along with their counterparts in Tsukuba, Munich, Huntsville, and Moscow. Most items have a barcode that can be read by a laser device. These barcodes are similar to those found on products in terrestrial stores or radio frequency identification chips, and are tracked in a database known as the Inventory Management System. The ISO works with the rest of the flight control team to build stowage notes for crew activities. These notes tell crew members where to find the tools and equipment they will need, and where everything goes when they are done. Gathering and stowing tools takes a significant amount of time and is built into the time allocation of each activity. The ISO works out how to unpack and put away cargo brought up to the ISS in arriving vehicles, how to pack whatever needs to be returned to Earth, and where to temporarily store items that will be thrown away. Each week, the ISO tags up with the crew during a short conference to make sure all the instructions that the crew members received for stowage management that week were clear, to answer any questions they may have, and to start the planning process for the next week. Even with barcodes and the ISO team on the ground, items get lost or misplaced. When this happens, the flight control team will actually create a “wanted” poster, alerting crew members to keep their eyes open for the missing hardware. Although most missing items are small, even large ones can disappear, as was the case of a pump module that measured 72.9 x 45.0 x 45.7 cm (28.7 x 17.7 x 18.0 in.). That pump module was eventually found tucked behind a rack. As the increment gets closer, placeholder events documented in the IDRD (e.g., EVAs) evolve into specific tasks such as repairs or experiment payload deploy. The final IDRD is published 1 month before the start of the increment. At this point, planning enters the execution phase with the Operations Planner (OPS PLAN) leading the detailed schedule development. Planning by the flight control team begins in parallel with the final phases of IDRD development. This allows