The Space Shuttle Discovery's mission STS-119, launched on March 15, 2009, was a pivotal operation in the assembly and enhancement of the International Space Station (ISS). This mission's Execute Package FD12, dated March 26, 2009, provided detailed instructions for the crew's activities on Flight Day 12, focusing on pre-landing communications checks and preparations for re-entry and landing. Understanding the context and content of this execute package offers insight into the meticulous planning and execution required for such complex space missions.

Overview of STS-119

STS-119 was the 125th flight of NASA's Space Shuttle program and the 36th mission for the orbiter Discovery. The primary objective was to deliver and install the fourth starboard Integrated Truss Segment (ITS) and the fourth set of solar arrays and batteries to the ISS. These components were essential for augmenting the station's power generation capabilities, enabling the accommodation of a larger crew and supporting future scientific endeavors. The mission also involved the exchange of crew members, with Koichi Wakata of the Japan Aerospace Exploration Agency (JAXA) joining the ISS and Sandra Magnus returning to Earth after an extended stay. The mission duration was 12 days, 19 hours, 29 minutes, and 33 seconds, culminating in a successful landing at Kennedy Space Center on March 28, 2009. ([nasa.gov](

Understanding the Execute Package

An Execute Package is a comprehensive document provided to the Space Shuttle crew, detailing the daily schedule, procedures, and tasks to be performed during each flight day. These packages are meticulously crafted to ensure mission objectives are met while maintaining crew safety and operational efficiency. They encompass a wide range of activities, including scientific experiments, maintenance tasks, spacewalks (extravehicular activities or EVAs), and, as in the case of FD12, preparations for re-entry and landing.

Contents of FD12 Execute Package

The FD12 Execute Package for STS-119, dated March 26, 2009, outlined the following key activities:

  • Pre-Landing Communications Checks: Scheduled communications checks with White Sands Space Harbor (WSSH) and Dryden Flight Research Center (DFR) were to occur one day earlier than usual due to timeline constraints. These checks were crucial for ensuring clear communication channels during re-entry and landing operations. The procedures specified that during the WSSH check, Mission Control Center (MCC) would contact the crew on UHF radio, and the crew's responses would be triple simultaneous (triple simo). For the DFR check, MCC would make individual calls on different frequencies, with the crew responding in triple simo to all calls. Notably, the MILA (Merritt Island Launch Area) communication check was scheduled for Flight Day 13 at the nominal L-1 time frame, with MCC routing a payload bay camera to satisfy the video component of the DFR check. Video was not required for the WSSH check. ([](
  • Post-EVA EMU Reconfiguration and Transfer: Following the completion of the mission's third EVA, procedures were outlined for reconfiguring the Extravehicular Mobility Units (EMUs) and transferring items to the airlock floor bag. This process was divided over two days, with one hour allocated on FD10 and the remainder to be completed on FD11. The updated procedure included a verification section for transfer items, ensuring all equipment was properly accounted for and secured. ([](
  • Grease Gun Cleanup: The package specified the materials required for the 15A Grease Gun Cleanup procedure, including dry towels, ziplock bags, and airlock restow items. This task was essential for maintaining the cleanliness and functionality of the equipment used during the mission. ([](
  • Airlock Restow: The crew was instructed to begin tidying up the airlock by returning tethers to the tether staging area and placing any tools not in bags into the "Done Tools" mesh bag. This process ensured that all equipment was properly stowed and secured, facilitating a smooth transition to re-entry preparations. ([](

Significance of FD12 Activities

The activities outlined in the FD12 Execute Package were critical for the safe and efficient conclusion of the STS-119 mission. The pre-landing communications checks ensured that all communication systems were functioning correctly, which is vital for coordinating re-entry and landing operations. The post-EVA EMU reconfiguration and transfer procedures were necessary to prepare the crew for re-entry, ensuring that all equipment was properly secured and that the crew was ready for the transition from microgravity to Earth's gravity. The grease gun cleanup and airlock restow tasks were part of the standard protocol to maintain the shuttle's cleanliness and operational readiness, preventing any potential issues during re-entry and landing.

Conclusion

The FD12 Execute Package for STS-119 exemplifies the meticulous planning and attention to detail inherent in NASA's space missions. Each task and procedure was designed to ensure the safety of the crew and the success of the mission's objectives. By understanding the components and significance of this execute package, one gains insight into the complexities of spaceflight operations and the critical importance of thorough preparation in the execution of space missions.

Sources

  • NASA — STS-119 Mission Overview —
  • Editor — NASA STS-119 Execute Package FD12 —
  • Editor — NASA STS-119 Execute Package FD10 —