User:Bradrb

Thermal is one of two EECOM Space Shuttle flight controller MPSR positions. The Thermal is primarily responsible for all vehicle cooling and management of water produced by the Shuttle's fuel cells for cooling, crew consumption, and transfer to the International Space Station (ISS).

Automatic Thermal Control System (ATCS)
The ATCS consists of two fluid coolant loops filled with Freon-21. These loops pick up heat from the orbiter's fuel cells, Water Coolant Loops, and various electronics external to the crew cabin. This heat is then rejected primarily by the radiators located on the payload bay doors, but may also be rejected by the Flash Evaporator or Ammonia Boiler systems. The Thermal is responsible for maintaining the Freon-21 within acceptable limits.

Flash Evaporator System (FES)
The FES provides additional cooling to the ATCS when needed by spraying water produced by the fuel cells into the vacuum of space, resulting in vaporization of the water. The FES consists of two, redundant cores that may be used simultaneously in high heat load situations and three redundant controllers. The Thermal is responsible for managing usage of the FES based on heat load and demand for stored fuel cell water. The Thermal may also be required to troubleshoot the formation of ice that has been known to collect within the FES cores due to improper vaporization.

Ammonia Boiler System (ABS)
The ABS work similarly to the FES. However, the ABS is intended for use while the Shuttle in exposed to Earth's atmosphere. It is primarily used to provide cooling after landing until Ground Service Equipment can provide cooling. The Thermal will determine when it necessary to activate this system.

Water Coolant Loops (WCL)
In order to prevent astronaut exposure to toxic substances, all equipment within the Shuttle's crew cabin are water cooled. This includes thermal conditioning of cabin air. This heat is then transfered to the ATCS. The Thermal is responsible for maintaining adequate cooling to all equipment. It is also a major concern of the Thermal to prevent freezing of a WCL where it interfaces with the ATCS.

Supply Water System
The Supply Water System consists of four tanks contained within the crew cabin that stores water produced by the Shuttle's fuel cells. This water may be consumed by the astronauts, used for cooling by the FES, transfered to the International Space Station, or it may be relieved overboard. During typical operations, the Thermal is primarily concerned with the management of the water in this system. This requires the scheduling of activities to prevent overfilling the system while maintaining enough water in the system to provide needed cooling.