The LPS is composed of three major subsystems: the Checkout, Control and Monitor Subsystem (CCMS), the Central Data Subsystem (CDS), and the Record and Playback Subsystem (RPS).[1]
The Checkout, Control and Monitor Subsystem (CCMS) controls the actual processing and launch of the Space Shuttle.[4] This subsystem consists of the staffed consoles in the firing room, as well as minicomputers, and data transmission and recording systems, which monitor the pre-launch performance of all electrical and mechanical systems on board the Shuttle vehicle. The various systems being monitored are managed from operator-controlled consoles, which are clustered together based on the type of systems.[1] The LPS master console in the firing room links the CCMS with the other subsystems of the LPS.
The Central Data Subsystem (CDS) consists of a cluster of high-end minicomputers which store vital data such as vehicle test and performance data, test procedures, historical data, etc.[4] There are two primary interfaces into the CDS. The first is a real-time interface with the CCMS. The second is a video simulation interface which allows testing of firing room systems without the need to have a vehicle present.[1]
The CDS originally consisted of two mainframe computers. It was upgraded in 1999 to its current clustered state, and was renamed the Shuttle Data Center (SDC)[1]
The CDS/SDC is located on the second floor of the Launch Control Center.
The Record and Playback Subsystem (RPS), as the name implies, records unprocessed data from various sources during testing and countdown. This can be played back at a later time for analysis. The RPS consists of tape recorders, telemetry equipment, and computers to perform analysis and data reduction.[4]