Inside the International Space Station: Thermal Control System and SAFER Astronaut Training Manuals

LEARN ABOUT OUR NEW SPACE STATION FROM THE TEXTBOOKS USED BY THE ASTRONAUTS! These astronaut and flight controller training manuals, produced by the Mission Operations Directorate (Space Flight Training Division branch) at NASA's Johnson Space Center, represent a major part of the formal flight crew training process. The manuals and workbooks are extremely detailed and comprehensive, and are designed for self-study. Each is heavily illustrated with vivid line drawings, engineering schematics, and other charts and figures. A full listing of all acronyms and abbreviations used in the text is included. Most include self-test questions and answers. They provide a superb way to learn about Station systems, hardware, and operational procedures. Special emphasis on crew interaction with the displays, controls, and hardware is included.

This up-to-date training manual covers two major areas: Thermal Control Systems and the emergency EVA propulsion backpack known as SAFER. It contains 133 excellent illustrations, figures, tables and charts.

THERMAL CONTROL SYSTEM: Throughout the life of the Space Station, experiments, equipment, and crewmembers inside the modules are generating heat that must be removed. Outside the modules, experiments and equipment must be protected from the environment in low Earth orbit. The purpose of the Thermal Control System (TCS) is to maintain Space Station equipment and payloads within their required temperature ranges. TCS Architecture - The Space Station TCS is composed of Passive and Active thermal control systems. The Passive Thermal Control System (PTCS) consists of insulation, coatings, heaters, and heat pipe radiators. Its components generally have few operational requirements and require low maintenance. PTCS components are also less complex and easier to implement. The Active Thermal Control System (ATCS) uses a mechanically-pumped fluid to perform heat transfer. Although this approach is more complex, the ATCS handles much greater heat loads and provides a higher degree of control over how the heat loads are managed. USOS Passive Thermal Control System - Since temperatures vary drastically across the Space Station, thermal control requirements are different and unique to each location. Temperatures along the truss decrease as the distance from the modules increases because most of the heat is generated around the module area. Temperatures around the modules can vary from -126° to 149° Celsius (C) (-195° to 300° F), while temperatures at the outer limits of the truss can vary from -184 ° to 149° C. SAFER: The Simplified Aid for EVA Rescue (SAFER) is a small, self-contained, propulsive backpack system used to provide free-flying mobility for an extravehicular (EV) crewmember. SAFER is a single-string system for contingency use only; therefore, it does not have system redundancy. SAFER is designed to be used as a self-rescue device for a separated EV crewmember in situations when the Orbiter is docked to a large structure such as the International Space Station (ISS), and therefore cannot provide rescue capability. For these types of EVAs, SAFER will be worn by every EV crewmember during all EVA operations. SAFER is a Johnson Space Center (JSC) project developed and built for use on ISS. A successful on-orbit SAFER Detailed Test Objective (DTO) was conducted on STS-64. This untethered DTO flight test demonstrated SAFER's operational capabilities and collected performance data to augment the design and development of the final SAFER. The STS-76 SAFER was a transitional unit between the DTO unit flown on STS-64 and the final production unit. Hand controller deployment was performed by a tethered but free-floating crewmember; SAFER powerup was performed by a crewmember in a foot restraint on STS-86. SAFER fits around the Extravehicular Mobility Unit (EMU) Primary Life Support Subsystem (PLSS) without limiting suit mobility. SAFER utilizes 24 gaseous-nitrogen (GN2) thrusters to provide 6 degree-of-freedom maneuvering control.