CHAPTER 12 DAY IN THE LIFE: EMPTY HOUSE—DECREWING THE INTERNATIONAL SPACE STATION 218 was identified and unpowered, the flight controlled team would wait approximately 30 minutes to an hour for a fire to extinguish, and then reactivate ventilation to maintain the ISS atmospheric conditions and dilute any smoke in the cabin. If the fire reignited, ventilation would again be shut down. Additional scrutiny and powerdowns would follow prior to reactivating ventilation. Recrewing Per the ISS Program priorities, the team also took time to determine what actions, both on the ground and on board ISS, would best prepare for the arrival of a new crew to a decrewed station. This included identifying any consumables or equipment that would need to be launched with the new crew members, or prior to their arrival. Additionally, the team identified a list of items that the crew would need for quick access upon entering the station. This equipment included tools, air sampling devices, and personal protection equipment (i.e., gloves, goggles, masks) in case of an emergency on board while the space station was uninhabited. The current crew would gather these items and stage them in the Russian Segment where the new crew would be docking. A recrewing procedure and timeline was developed to return the ISS to a nominal configuration in the same way the team developed a procedure and timeline for implementing the decrewed configuration. Training Two important aspects of training were associated with developing the decrewed configuration. The first concern was crew training. In addition to preflight ground training, new crews received “handover” training from the current space station crews. This training revealed the most up-to-date configuration of the ISS, and provided hands- on tips and tricks to performing common procedures. If decrewing happened, the new crew would not have the benefit of this handover training. With that in mind, on-board crew members began making video recordings of common procedures, including voice-overs of the topics usually included during handover. They also recorded video tours of the ISS helping the ground teams understand the exact physical configuration of station systems and stowage. These videos were added to the training of the next crew and they continue to be used for future crew training. Additionally, the next-to- launch crew members aided in the development of the decrewing and recrew procedures. This added to their familiarity with the procedures and would greatly benefit the team in the event the ISS was decrewed. Second, the flight control team executed a decrewed configuration simulation. To do this, the ISS training team configured the ISS simulator to the expected decrew configuration. A team of experienced operators were then put through an exercise to respond to simulated equipment failures and emergency situations. This was used to test the decrew configuration and operational response. Although the team learned that some procedures would need to be modified, the simulation showed that the flight control team could maintain the ISS in a decrewed configuration. Conclusion When Progress 44P was lost due to a problem in the engine of the Soyuz U rocket’s third stage, the ISS Program was faced with the possibility of needing to leave the ISS uncrewed for an unknown amount of time. As seen in the past, the program, engineering, and operations team quickly stepped up to the challenge. First, priorities were defined. These included maintaining ISS safety and operability, increasing ISS system robustness, and assuring the capability of flight control teams to respond to off-nominal situations, thus enabling a returning crew to quickly recover nominal operations and continue scientific research. Using these priorities and building on previous discussions and documentation, the ground teams developed procedures, plans, and training to place the ISS in the best configuration to support uncrewed operations and return to a crewed configuration. The Russian Space Agency was able to determine the cause of the Progress 44P accident and return to