After the first successful flight of an Apollo-Saturn V Rocket, Wernher von Braun credited success "to our automatic checkout procedure."

NASA's critical operations for the Apollo manned lunar missions included the launch control countdown support and equipment ground testing / acceptance checkout for each stage of the Saturn spacecraft and its associated systems. This automatic checkout was the responsibility of the ACE (Automatic Checkout Equipment or Acceptance Checkout Equipment) at Cape Canaveral's Launch Control Center. Through the use of computers, display consoles, and recording equipment, ACE provided an instantaneous, accurate method of spacecraft pre-flight testing. The "brain" of the ACE was the RCA 110A Saturn Ground Control Major Computer System.

ACE relied on the 110A computer as its main constituent, directing the associated input / output equipment for these integrated system checkouts and launch control procedures. Through this process control system all Saturn stages are checked, and data from the engines, and I.U. (Instrument Unit) guidance, flight control, propellants, measurement and telemetry systems was provided. All test transmissions went through the RCA 110A computer; and if it failed, the entire checkout would stop. IBM wrote both the flight programs and the Saturn Operating System that ran on the RCA computers and executed ATOLL (Acceptance Test Or Launch Language) procedures.

The RCA 110A provided a number of significant capabilities:
Input / Output processing simultaneously, General purpose data processing and reduction, Ability of two RCA 110A's to work in tandem via data link, General purpose computing, Real-time control monitoring and testing of multiple digital and analog systems, and Versatile peripheral equipment.

The RCA 110A System consisted of the following compliment of cabinets:
Main frame, Power supply, Memory, Data link, Discretes, Switching, and Peripherals.

The RCA 110A data channels controlled signals to and from many other interfaces such as:
Control consoles, The dual data links to the pad, Digital data systems of the launch vehicle, Computer display systems, The spacecraft computer system, and The launch countdown clock system.

The RCA 110A had two general modes (semi-automatic (Fig 4) and automatic) of operation available for use, and three basic features:
Discrete actions called up from the ESE switches; Call up from the display consoles of test programs and discrete requests or monitoring; and Periodic monitoring of test points, discrete status, and red-line values.

The RCA 110A Saturn Ground Control Computer System primarily supported the Saturn V missions from Complex 39 as shown in Figs. 3 and 4. An RCA 110A 'master' computer system was located in the Launch Control Center (LCC). And an RCA 110A 'slave' computer system was located in the Launch Umbilical Tower (LUT) on the Mobile Launcher Platform (MLP) upon which the Saturn rocket was erected. The slave computer interfaced with the launch vehicle, issuing commands and receiving responses.

Engineers could initiate launch vehicle tests from display consoles linked to programs stored within the master RCA 110A. In performing a test, the responses from each stage were evaluated based on the applied stimuli. The 110A computer would direct the data received from these tests to the stimulus-generating equipment, to be displayed locally at a selected test station, or to be recorded for later hard copy printout. There were 15 display systems in each LCC firing room, with each system capable of giving digital information instantaneously. The test conductor's CRT console was the focal point for maintaining control of all test operations and the computer. 

During the Saturn I program, automation moved forward at a slow, deliberate pace; at any time the launch team could have reverted to manual operation. By the time of the first Saturn IB launch in February 1966, however, KSC was firmly committed to automated testing.  While a completely automated checkout was still a long way off, the RCA 110A computer (a 110 with increased memory) was "on line" for the first IB operation. On-line status represented the decision to use the Saturn IB missions as a testbed for Saturn V automation. As the early use of the RCA 110 indicated trouble-free operations, the 110A major computer became the workhorse of the Saturn V spacecraft ground testing checkout and countdown support at the Cape. (Source: NASA.gov / RCA)


This artifact originally belonged to a NASA Kennedy Space Center engineer who lived in Melbourne, Florida.

NASM, the National Air and Space Museum, of the Smithsonian Institution in Washington, DC, has two examples of this RCA 110A component.

This circuit board measures approximately 8 inches x 4.25 inches; it uses discrete components and contains precious metals ( * this board does not have the connector interface * ).

The last images are reference diagrams (Figs 1-5) related to the RCA 110A information listed above, and a reference photo of the Launch Control Center's ACE system during the Apollo era.

In depth technical information for the NASA RCA 110A computer system is available at the following links: www.hq.nasa.gov/pao/History/SP-4204/ch16-2.html , www.alternatewars.com/SpaceRace/Saturn/ASD_II_Satu... .

Several pages of NASA / RCA 110A Saturn Ground Control Major Computer System information will be included with this purchase.

A classic Apollo-Saturn circuit board for your NASA hardware collection!