It processes video and data inputs from cameras and video tape recorder channels and routes them to monitors, the VTR or the ground by downlink. Typical uses of the CCTV system for monitoring and recording mission activities include payload bay door operations, remote manipulator system operations, experiment operations, rendezvous and stationkeeping operations, and onboard crew activities. The CCTV system consists of the video control unit, television cameras, VTR and onboard television monitors 1 and 2. A and B can be interleaved with the video output, along with Greenwich Mean Time data from the orbiter master timing unit. The VCU also generates a standard test pattern for use in adjusting the monitors and verifying downlink and provides multiplex capability for two split-screen outputs.
All television cameras are identical with the exception of accessory hardware.
Any camera can be equipped with three types of interchangeable lens assemblies, depending on mission requirements. Both monochrome and color lenses are available with normal field of view. Color lenses are also available with a wide-angle field of view. In addition to focus control for sharp images, several special lens control functions are available. All functions can be controlled by both onboard and ground uplink commands.