The Coldplate is the black cushion that sits on top of the MBSU to keep it cool. Ammonia runs through tunnels in the cold plate collecting waste heat from the MBSU.
What do Radiators do on the EATCS? Radiators are used in the External Active Thermal Control System. The radiators are fully deployable and retractable along with the ability to swivel so that they can maximize heat rejection into space. It is through the radiators that waste heat from the ISS is rejected into space. The radiators are attached to Radiator Beams, which are attached to one of the ISS Truss sections by the Thermal Radiator Rotary Joint (TRRJ), which rotates to allow for Radiator Beam rotation of 104 degrees (See Exhibit 8, 9, &10). When the radiators are in sunshine they are turned with their edges toward the sun to maximize heat radiation away from the radiators into space. When the earth eclipses the ISS from the sun the radiators are turned face to earth to receive some of the earth’s warmth so that the radiators do not freeze. The direction and deployment of the radiators is controlled by the Thermal Control System Software, which is an intricate computer program that monitors temperatures within the radiators.
The radiators are located on the Integrated Truss Assembly, which provides the structures to attach and link together the many components and modules of the ISS. Radiators are located on Truss T1 and S1 that are on either side of the center Truss T0, where Destiny Lab is located. There are 12 Truss segments in all that when combine make up the Integrated Truss Assembly which provides the structural design of the ISS.
The web site http://www.nasa.gov/externalflash/ISSRG/pdfs/integrated.pdf has an excellent picture of the Integrated Truss Assembly structures.
