Communication, Command and Telemetry System (CCATS) in the Apollo era

Picture #01

Credit to UNISYS.

Picture #02

Credit to UNISYS.

Picture #03

Credit to NASA.

Picture #04

Credit to NASA.

Picture #05

Credit to NASA.

Picture #06

Credit to NASA.

Picture #07

Credit to NASA.

The seven camera viewpoints on the CCATS floor plan.

Credit to NASA.

Floor plan of the Communication, Command and Telemetry System (CCATS)

CCATS floor plan
CCATS consisted of six subsystems:
  • the communications subsystem;
  • the command subsystem;
  • the voice subsystem;
  • the telemetry subsystem;
  • the pneumatic tube subssystem and
  • the central processor
CCATS Central Processor (Room 116 and 116B)
Three systems can be distinguished (A, B and C)
At the core of each system a mainframe UNIVAC 494. To this mainframe peripheral systems were connected: additional magnetic core memory units, disk drive units, tape units, line printers, card readers, teletype units, data adapters etc..

One of those three systems was sufficient to support an Apollo mission.
One mainframe was active, a second mainframe was in dynamic standby and did the same work in parallel with the primary mainframe but its output was not used to support the mission. A switch to the standby mainframe could be done swiftly in case the primary would fail. The third mainframe was kept in reserve or was used for simulations, to make preparations for the next upcoming Apollo mission.

The CCATS was located at the first floor of the Operations Wing of the Mission Control Center (MCC) in Houston)
(This MCC building had 3 wings: the Administrative Wing, the Lobby Wing and the Operations Wing)
The Operations Wing had 3 floors. In 1960's and 1970's there were two Mission Operations and Control Rooms, one MOCR at the second floor and the other MOCR at the third floor).

Typical system configuration of an UNIVAC 494 for CCATS

UNIVAC 494 system configuration

In this diagram a typical UNIVAC 494 system configuration is shown as used in the MCC.
The peripheral systems are depicted for one of the mainframes (CPU A).
The diagram shows how all the three mainframes were interconnected and also how they are connected with other MCC systems.

An overall context diagram is shown on this page about the MCC.

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Copyright 2020 by Sander Panhuyzen
Comments and questions welcome. All pictures and drawings contained on these pages are the author's, unless otherwise noted. No unauthorized reproduction without permission.