Mission Operations Control Room (MOCR)

Wide angle view of the Mission Operations Control Room just after lift-off of Apollo 15.
The plots on the large screens are meant to enable the flight controllers to ascertain whether the Saturn V stays within its flight envelope. Altitude, downrange distance, inertial flight path angle and velocity are the most important parameters for the assessment. The 2nd and the 3rd plot screens from right to left, are also meant to oversee the several abort mode regions in a flight path angle versus velocity plot. An abort will result in a landing into the Atlantic Ocean of the Command Module or a contingency orbit for the Command & Service Module.

Credit to NASA.

Floor plans of the Mission Operations Control Room (MOCR) and the Projection Room

Floor plan of the Mission Operations Room is based on the figure in ref.1 page 1-01-28-01.
Arrangement of projectors and fold mirrors in the Projection Room is based on the figure in ref.1 page 1-01-23-01.
Eidophor physical appearance based on film clip of ref.2
Eidophor physical dimensions based on ref.5
Projector assembly unit physical appearance based on film clip of ref.2 and ref.3 figure 2-2-4.
Projector assembly unit functional description based on film clip of ref.2 and ref.6 page 80 and 81.
Projector assembly unit physical dimensions have been estimated.
The arrangement of the seven slide projectors of the projector assembly unit is an educated guess.

Mission Operations Control Room
Fourth row of consoles (The "Trench")

BOOSTER - Booster System Engineers
Monitoring the performance of all three stages of the Saturn V

OSO - Orbital Science Officer
EO - Experiments Officer
ASE - ALSEP Senior Engineer
When all three stages of the Saturn V had done their work, the tasks of the BOOSTER engineers were over. The mission had entered a phase in which science became an important focus. The console was taken over by the OSE, the OSE was the primary interface between the flight control team and the scientists in the Science Operations Room and the Satellite Control Room. Altough the EO was sitting in the Science Operations Room and the ASE in the ALSEP Control Room both officers could be found occasionally in MOCR when science activities required intensive consultation between the science team, the flight controllers and the flight crew. (ALSEP: Apollo Lunar Surface Experiment Package)

RETRO - Retrofire Officer
Is reponsible for getting the spacecraft back in case of mission abort and during the return phase of a mission. During the mission RETRO always kept a list of abort options to take swiftly adequate actions in case of emergencies.

FDO - Flight Dynamics Officer
Monitoring the flight trajectory of the launch vehicle and the spacecraft. FDO was also responsible for producing the data to compensate for flight path deviations.

GUIDO - Guidance Officer
Ensure that the Apollo Primary Guidance, Navigation and Control Systems (PGNCS) on both the Command Module and the Lunar Module operate correctly.

Third row of consoles

SURGEON - Life Systems Officer / Flight Surgeon
Medical doctor who monitored the health of the crew.

CAPCOM - Capsule Communicator
Was usually a colleague astronaut and was in his role as flight controller the only one in the room who was allowed to talk directly to the spacecraft's crew.

EECOM - Electrical, Environmental and Communications
Watching over the Command and Service Module's electrical and environmental systems.
The "communications" part was moved over to INCO after the Apollo 10 mission to ease the elaborate task of EECOM.

GNC - CSM Guidance, Navigation and Control
The GNC operator monitored the state of the reaction-control systems and the Service Module's main engine, as well as the hardware components of the spacecraft's guidance systems.

TELMU - Telemetry, Electrical and EVA Mobility Unit
Watching over electrical and environmental systems of the Lunar Module and the Lunar suits.

CONTROL - LM Guidance, Navigation and Control
The CONTROL operator monitored the state of the reaction-control systems, the descent and the ascent engines of the Lunar Module, as well as the hardware components of the spacecraft's guidance systems.

Second row of consoles

INCO - Instrumentation and Communication Officer
INCO monitored the communications systems for both the Command Module and the Lunar Module, taking these tasks from EECOM and TELMU respectively.

O & P - Operations and Procedures
Making sure that flight controllers followed all of the procedures when asking for data or communicating with people, all according to flight control operations handbook.

AFLIGHT - Assistant Flight Director
Duplicating the flight director's duties, monitoring the mission and supplementing the flight director's control.

FLIGHT - Flight Director
The flight director, FLIGHT, can be compared to an orchestra leader. FLIGHT had ultimate authority to do anything necessary to ensure the crew's safety and the mission's success, in that order of priority.

FAO - Flight Activities Officer
FAO, was the timeline manager for the mission and ensured that the preplanned activities for each mission were occurring on schedule.

NETWORK - Network Controller
NETWORK functioned as the interface with the global network of MSFN data collection and transmission stations which served NASA.
(MSFN: The Manned Space Flight Network was a set of tracking stations built to support the American Mercury, Gemini, Apollo, and Skylab space programs)

First row of consoles

PAO - Public Affairs Officer
PAO provided audio narration for the mission, which would be broadcast on radio and television. PAO commentary helped the public understand what they were seeing on their screens during the televised portions of a mission, and also gave news media something on which to base their own commentary.

DFO - Director of Flight Operations
The director functioned as an interface between Mission Control and space center management.

HQ - NASA Headquarters (Mission Operations Directorate)
This position acted as a liaison between the Mission Control team and NASA headquarters in Washington, DC.

DOD - Department of Defense Officer
A representative from the Department of Defense, usually a high ranking officer.
The military was responsible for coordinating the recovery of the spacecrafts after splashdown.

Projection Room

Edited version of figure on ref.4 page 43.

Extracted from ref.3 figure 2-2-4.

Edited version of ref.7 figure 4-4.
In this picture is illustrated the internal workings of a scribing or plotter projector.

Plotting curves
A stylus mounted in a glassplate is moved with high precision by servo motors. These servo motors were controlled by a Projection Plotting Controller which translated the digital input plotting data from the RTCC into control signals.

Scribing characters
The Plotting Controller also had control logic for scribing a set of 77 characters and symbols onto the opaque slide. The input data should contain the character ID, the scale factor and a position coordinate to have a character with desired size scribed in a particular spot on the slide.

Operating principle of the Eidiphor EP6

In the picture on the left is shown the principle of an Eidophor projector
An electron gun draws the video images with a scan frequency of about 17 kHz onto a concave mirror which was covered with a thin film of oil. The optical properties of this oil was proportional susceptible to the intensity of the scanning electron beam. This film of oil made it therefore possible to modulate the reflection properties of this mirror arrangment. By illuminating this concave surface with a powerful light source and the use of additional optics video signal were in this way transformed into projected optical images.

The Eidophor EP 6 was equipped with three guns and three optical arrangements to facilitate color video in which each video image is composed out of three overlapping images for the primary colors red, green and blue.

Video still from ref.2; timestamp: 9:00 (year 1970)

An Eidophor EP6 in the Projection Room

Video still from ref.2; timestamp: 9:04 (year 1970)

An Projector Assembly Unit in the Projection Room

The Group Displays were backlit by three Eidophor projectors and two projector assembly units.
Large mirrors were used to fold the optical paths.

The three Eidophor projectors were used to display video information.

The projector assembly units were used to display plots on background images. An assembly unit was basically a bank of seven slide projectors to superimpose images from seven different sources onto a single screen.

    Three types of projectors could be distinguished (self-made name type).
  • Type B(ackground reference) projector (1x), to project a reference background slide like a worldmap.
  • Type P(lotter) projector (4x), to project an opaque (metal coated) slide. This projector type was equipped with a micro X-Y plotter to scratch or scribe information onto the opaque slide which resulted in the projection of the scracthed information onto the group display. A plot of a real-time groundtrack of a spacecraft projected on a worldmap is an example of the capabilities. If all four plotter projectors were in use, projector color filters were used to make a distinction between the scribed information.
  • Type S(ymbol or spotting) projector (2x), to project a moving symbol or icon onto the group display. The projector was also equipped with a micro X-Y plotter to move the slide containing an icon to show, for example, the location of a spacecraft in real-time on a world map.
In the floor plan only the optical paths of the background projectors of the assembly units are shown.

Group Displays of the Mission Operations Control Room (MOCR)

This picture illustrates how the large group displays were used. This example reflects a mission phase in which the spacecraft is on its way to the moon and the lunar module is about to be docked by the CSM (the mother spacecraft) and to be extracted from the S-IVB stage. The large displays were large etched glass panels which were backlit by various projectors.

MOCR Group Plotting Display: Principle of Operation

Edited version of ref.3 figure 3-3-4-1.

This illustration shows how geographical information pertaining the spacecraft was shown.
For simplicity only three projectors out of the bank of seven projectors are shown.

Three type of projectors were used:
Projector type B to project a slide containing a reference background, in the current example the reference background is a world map with a geographic grid;
Projector type P to project the progressing ground track. A computer driven micro plotter was scribing onto an opaque slide scratching the covering layer which resulted in a glowing curve projected on the display screen;
Projector type S to project a symbol or an icon representing the spacecraft. The projector was equiped with computer driven optics to show the position of the spacecraft on the projected world map.

Some more information about how the group displays were used can be found on this page

Paper model (1:25) of the Mission Operations Control Room (MOCR)







  1. MCC Operational Configuration for Mission J1
    AS-510 / SC-112 / LM-10
    Apollo 15
    PHO-TR155, 15 April 1971
    by the Manned Spacecraft Center, Houston

  2. This is Mission Control
    A NASA report about the Mission Control Center (documentary film)
    Produced by A-V Corporation, Houston, 1970
    Source: Internet Archives: https://archive.org/details/ThisIsMissionControl

  3. Mission Control Center Houston
    Familiarization Manual
    PHO - FAM001
    Prepared by Philco, Houston, 30 June 1967

  4. The History of the EIDOPHOR Large Screen Television Projector
    by Heinrich Johannes
    Gretag Aktiengesellschaft
    Switzerland, 1989

  5. Swiss technology on the moon
    Blog by Juri Jaquement
    Curator of the Information and Communication Technology Collection
    Museum of Communication, Bern, 13 March 2019

  6. Apollo Mission Control
    The Making Of A Historic Landmark
    by Manfred Ehrenfried
    Springer International Publishing AG, part of Springer Nature, 2018

  7. Displays Formats Manual
    PHO - TR515
    Under Contract NAS 9-1261
    Prepared for NASA Manned Spaceflight Center
    By Philco-Ford Corporation, 12 January 1973

  8. Science Operations Support Plan
    Prepared by NASA Flight Control Division
    Manned Spacecraft Center, Houston, (Release date not mentioned in report)

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Copyright 2020, 2023 by Sander Panhuyzen
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