Hawes Mechanical Television Archive by James T. Hawes, AA9DT
Col-R-Tel on the Moon (Part 2)

How the Downlink Converts Moon Signals

Moonscape,  
       with craters receding into inky distance. A shadow of the Command 
       Module glides over barren plains. (NASA photo)

NASA photo

Moon Col-R-Tel used its fields in a different way than Earth TV did. Moon video painted a color picture in six fields. But Earth TV painted that color picture in only two fields. For this reason, video coming from the Moon required conversion before we could view it.

Video 101. We need to define a few terms: A frame is one picture in a series that appears as moving video. Earth televison systems built each video frame from two fields. A field was half of a video frame. Each field contained alternate scan lines: Odd lines in one field. Even lines in the other. The scan lines ran left to right, and drew the picture on the screen. Back to the two video fields. Over time, two fields meshed, reducing flicker effects for the viewer.

Moon vs. Earth Col-R-Tel. The Moon color system was Earth Col-R-Tel in reverse. Recall that Earth Col-R-Tel transformed NTSC television signals into field-sequential signals. Video from the Moon was another matter. It was already field-sequential. The Earth downlink station translated this video to NTSC.

Standard TV sets could reproduce the downlink station's output. Downlink adapters made viewable pictures for home sets across the world. Now let's take a deeper look at the video arriving from the Moon.

Block diagram: Moon Col-R-Tel system (Farbfernsehen, mechanisches 
            Fernsehen)

Mooncam Process

The mooncam process complemented downlink station processes: The mooncam selected one of three colors per field and transmitted that color to the downlink station. Filters in the color wheel caused the camera to ignore or skip the other two colors. Skipping colors reduced the video bandwidth. Due to color-skipping, each color in a mooncam video only updated once per every three video fields. (Wetmore 20) Note: The output of an Earth Col-R-Tel adapter followed the same, lossy mooncam process.

Photo: Moon surface mooncam for lunar surface EVA, by  Westinghouse
WEC Mooncam for lunar surface, color (Wood 29)

Color sensor. RCA's GCTA camera transmitted a “field complete” signal. The camera relayed this signal during the horizontal interval of line 18. Before every green field, a phototransistor picked up a lamp shining through an aperture in the color wheel. There were two such apertures in the wheel. For this reason, every time the wheel revolved, the phototransistor pulsed its signal twice. (RCA 1-12, 1-20, 1-28, 1-29, 1-30, 1-35, & 1-36) The downlink station could use the “field complete” signal as a reference. This reference allowed the downlink to route the correct signal to each input of the color matrix and proc amp.

The WEC camera used a magnet and coil to detect a similar signal. (Apollo Color Television Subsystem Operation and Training Manual 3-9)

(R= Red; B= Blue; G= Green)
Moon Frame 1 Moon Frame 2 Moon Frame 3
Field 1:
R (Odd)
Field 2:
B (Even)
Field 3:
G (Odd)
Field 4:
R (Even)
Field 5:
B (Odd)
Field 6:
G (Even)
Skip B (Odd) Skip G (Even) Skip R (Odd) Skip B (Even) Skip G (Odd) Skip R (Even)
Skip G (Odd) Skip R (Even) Skip B (Odd) Skip G (Even) Skip R (Odd) Skip B (Even)
Transmit
R (Odd)
Transmit
B (Even)
Transmit
G (Odd)
Transmit
R (Even)
Transmit
B (Odd)
Transmit
G (Even)

Making data is tougher than discarding data. Just so, converting Moon Col-R-Tel to NTSC was more difficult than conversion going the other way. While Earth Col-R-Tel worked by losing color data, Moon Col-R-Tel (the downlink) worked by making color data. That is, Earth Col-R-Tel discarded two colors per NTSC video field. At the downlink station, Moon Col-R-Tel borrowed data from adjacent frames, and actually built new frames. The field-sequential to NTSC color conversion equipment was a form of mechanical television.

Time Delays. The downlink conversion process occurred during Moon telecasts, but delayed the output video. (Spacecraft Films, “TV Transmission 33:59 GET”) The Doppler correction alone caused about a 12-second delay. This delay resulted from a tape loop between machines. (Wetmore 20) Additional delays occurred during transmission from downlink stations to synchronous satellites in Earth orbit. Such transmissions occurred between downlink stations and NASA-Houston, and between NASA and other countries. In Europe and Asia, coaxial cable and TV standard conversion caused further delays.

Compensating for Doppler Shift

Doppler shift. Before the downlink station could begin its conversion, it had to correct for Doppler shift in the Moon signal. The shift varied depending on the relative motion of the Earth and the spacecraft. Standard TV sync circuits couldn't reliably lock a Doppler-shifted picture. Without Doppler shift correction, the pictures would tear and flip. The correction process was partly mechanical and partly electronic.

Video Backup. Before sending the Mooncam signals to Houston, downlink stations in California, Spain, and Australia made backup copies of the signals. For the local backups, the downlinks used Ampex VR-660B, video tape recorders. These were early helical VTRs for monochrome signals, not color. Yet because a mooncam didn't send a chroma signal, a monochrome recorder could still capture pictures in color! The VTRs used two-inch tape on reels. (Wood 11, 12)

Diagram: 
             Normal vs. Doppler-shifted horizontal sync. 2 examples: 1-Spacecraft departing; 
             2-Spacecraft approaching.
Normal (top) vs. Doppler-shifted (bottom) horizontal sync. Bottom-left: Departing spacecraft stretches sync & picture. Bottom-right: Approaching spacecraft squeezes sync & picture. (Adaptation from Grob 68)

Two Machines. Houston corrected the signals for Doppler shift. NASA used two, quadruplex, 2-inch videotape machines. One machine recorded. We'll call this machine the recorder. The other machine played back. We'll call this machine the player. (Wood, 7) The two machines operated as an electromechanical time base corrector.

Tape from the recorder ran to the player. Between the recorder and player, the tape was nearly slack. This slackness allowed one machine to operate faster than the other without breaking the tape. There was another complication: Normally when tape tension slackens, a tape sensor shuts down a tape machine. The answer to this problem was a counterweight between the players. The counterweight maintained just enough tape tension. This constant tension kept the tape sensors from stopping either machine. (Wetmore, 20)

Diagram: Apollo
            downlink processes, including Doppler corrector
Doppler corrector, field storage unit and NTSC encoder. (The “Color Converter” was a video disc recorder.) Source: Apollo Color Television Subsystem Operation and Training Manual 5-2.

The recorder taped the TV signal from the spacecraft. This TV signal included sync pulses that stabilized the picture. On the tape, the time between recorded sync pulses varied. This time depended on the direction of spacecraft motion with respect to Earth: When the spacecraft receded, intervals between sync pulses grew longer. When the spacecraft approached, the intervals grew shorter. On the Moon, heating and cooling of the sync generator circuits caused more phase shifts. (Wood 12)

Servo. A crystal-controlled servo drove the player. This servo locked on the NTSC color subcarrier frequency, 3.58 MHz. The servo’s other input was the taped horizontal sync pulses from the recorder. Normally, these horizontal sync pulses followed the NTSC standard and occurred at 15,734 Hz. The crystal frequency and the normal sync frequency had a common quotient of 7,867 Hz: The servo divided the crystal frequency by 455 to produce a 7,867-Hz signal. The servo also divided the horizontal frequency by two. Normally this operation would also produce 7,867 Hz. Yet due to Doppler shift, the result might be off by several Hz.

Subcarrier quotient. As its standard, the servo used the crystal subcarrier quotient (7,867 Hz). The servo compared the two quotient frequencies. Any difference between these two frequencies caused a correction voltage. The servo used this correction voltage to vary the player speed. The varying player speed corrected for differing intervals between sync pulses. Output sync matched the NTSC standard. The player's video output ran to the scan converter.

Conversion from Field-Sequential to NTSC

Downlink station color conversion. Time for a little review. On the Moon, cameras scanned one color video field at a time. After six color fields, a full color frame resulted. This was field-sequential scanning. On Earth, color TV sets scanned all three colors simultaneously. Every Earth field contained three colors. Two Earth fields made up a frame. The three primary colors arrived at an Earth receiver over a chroma signal. Chroma was separate from the monochrome (luminance) signal. The Earth set combined chroma and luminance and voilà: Color TV! But the mooncam didn't provide chroma. Instead, the mooncam mixed color and monochrome data. And that's why NASA needed a downlink converter. The downlink station had to convert the Moon video to Earth video. The conversion process repeated each Moon color field three times, as part of three Earth fields. (Repeats began after the first two Moon fields.)

Distributing data. Despite the data duplication, the downlink equipment never invented new picture elements. Instead of dreaming up the missing data, the process involved distributing received data. For example, Moon fields 1-2-3 became Earth Field 1. Moon fields 2-3-4 became Earth Field 2. Moon fields 3-4-5 became Earth Field 3. Westinghouse called this field-combination method the moving window. The moving window preserved the natural flow of motion over time.

Sheared frames. The downlink process also sheared a half line from the top many Moon fields. Other downlink circuitry added normal luminance, chrominance, burst, and sound to the Moon signal.

Diagram: 'Moving window' method of combining video fields

The “moving window” combined Moon video fields to assemble Earth video fields. Each Moon field repeated three times.

The downlink picture conversion process was analog. The idea was to record Moon fields serially and play them back in parallel. To store, repeat and combine Moon video fields, the Apollo missions used magnetic disc recorders. Ampex developed this type of recorder for use in sporting events. Starting in 1967, such recorders made possible the instant replays that football fans love. (Abramson, 117-118) Westinghouse modified Ampex HS-100 recorders for use in NASA downlink stations.

The stock HS-100 recorder had two discs, and recorded on both sides of each one. This recorder contained 1,800 tracks (450 tracks for per side, times two discs). Each track could record one video field. Alternate fields recorded on alternate disc sides. The HS-100 disc rotated at 3,600 rpm. In one rotation, each side of each disc could record or play back one video field. The next video field would record on the next side. There were four record-play-erase heads, one for each side of the two discs. The four heads could be active at once, with each head operating on a separate track. (Ennes, 485, 488-489)

Block diagram, conceptual: HS-100 disc recorder

Stock Ampex HS-100 disc recorder included 2 discs. Had one record-playback-erase head per disc side. Video fields alternated between disk sides: Field 1 on Disc 1, top. Field 2 on Disc 1, bottom, etc. (Adaptation from Dunlop 111.)

Probable Modification. Downlink operations required six tracks. (Specifications called for activity on five tracks, with the sixth track remaining unchanged.) The need for six tracks (five active at once) would have been beyond the HS-100's capacity. With four heads, the stock machine could only support four active tracks. Likely Westinghouse satisfied its requirements by adding a third disc and two more heads to the recorder. (Or maybe Westinghouse used two disc recorders.)

Right: Likely 3-disc modification of Ampex HS-100. NASA required 6 tracks & 5 simultaneous operations. These goals would require 6 heads A-F. Custom 3-disc, 6-head recorder would have satisfied requirement.
Art: Symbolic drawing of three-disc version of HS-100 recorder

Disc operations. The recorder performed a different task on each track. On each successive disc rotation, this task switched by one operation. Playback (read) tasks occurred simultaneously and built the output video field. Each output field included two matching Moon fields and one that didn't match. For example, one even and two odd fields, or two even and one odd Moon fields. Normal field interlacing caused this mismatch. (Source of the mismatch: Standard odd fields began scanning at the top-left corner of the screen. Even fields began scanning a half line away, at the top-middle of the screen.)

The disc recorder corrected the mismatch by introducing a brief delay. A half-line delay before starting the record head sheared off half a line. After the delay, the resulting Moon field matched the other two Moon fields. Leaving the non-matching field as-is would start scanning at the wrong screen location. A delay line in the disc recorder achieved the shearing effect. (Ennes 493, 495) The delay line was a passive, analog device of the quartz (not RCL) type. The delay before scanning was 31.5 microseconds. (Wood, 6)

Right: Two interlaced fields made up each video frame. First field, odd lines. Second field, even lines. Each field started on different part of screen. Downlink station had to convert every third field from even to odd, or odd to even. Conversion involved shearing off half of first line.

Art: Odd and even TV fields; how system converts 
            one type to the other

Output from Downlink Disc Recorder, Example

(R= Red; B= Blue; G= Green)
(E= Even Field; O= Odd Field)
Moon Fields → R1 + B2 + G3 B2 + G3 + R4 G3 + R4 + B5 R4 + B5 + G6
O — E — O E — O — E O — E — O E — O — E
Field to Shear → Shear B2 Shear G3 Shear R4 Shear B5
Earth Fields
(Output)
Field #1, RBG (O) Field #2, RBG (E) Field #3, RBG (O), Field #4, RBG (E),
Earth Frames
(Output)
R-B-G, Frame #1 R-B-G, Frame #2

About Disc Recorder Tables, Below

Photo: Model holding disc from Ampex HS-100 video disc recorder
Disc from HS-100 recorder (Ampex 8)

Video disc operation. The “Loading Moon Fields” tables below describe operation of the video disc. These tables derive from page 5-4, Figure 27 of this book: Apollo Color Television Subsystem Operation and Training Manual (by Westinghouse, or “WEC”). Each new disc rotation began immediately at the end of the previous rotation. (After Disc Rotation 6, the process at Disc Rotation 1 repeated, only with new data.) There was no time for heads to move radially. That is, “between disc rotations,” the six heads remained stationary. This mode of operation differed markedly from typical operation. Ennes (490) describes typical operation: One or more heads would step to a new track while another head recorded.

Error in Record-Playback Sequence. This page corrects an error in the manual's disc color sequence. The book gave the sequence as R-G-B (red-green-blue). A private email from the late Stanley Lebar clearly and emphatically states that the sequence was R-B-G. The basis of this sequence was the color wheel that revolved before the Moon camera lens. This wheel adhered to Peter Goldmark's original CBS specifications. Not surprisingly, the Col-R-Tel scanning disc also followed Goldmark's R-B-G scanning order.

RCA camera. According to the RCA camera manual, the RCA camera also followed the R-B-G sequence. (RCA 1-12) This sequence is why the same downlink equipment and program would work for both the WEC and RCA cameras.

There was no way to specify which color field was the “first one” to come from the Moon. (Those who wish to view the R-G-B order from the WEC manual may use the color-change buttons. These buttons are beneath each table below.)

First usable field. The disc had to contain three stored Moon fields. Otherwise, the disc couldn't play back enough data for one Earth field. The first four disc rotations recorded Moon fields into tracks 6, 1, 2, and 3. But what the disc played back was incomplete, and no usable Earth field resulted. Usable Earth fields didn't emerge from the system until Rotation 5. Each rotation took 16.7 milliseconds, so Rotation 5 wasn't complete until the 83-millisecond point. For that reason, there was a fleeting delay before the system could process the first Earth field.

The R-B-G colors for each track are examples from Westinghouse. (Apollo Color Television Subsystem Operation and Training Manual, Figure 27, 5-4.) For instance, in the first table: “Track 1: Red-Even.”

Art: Field-sequential video conversion. Reuse of Moon video fields in building Earth fields.
Repeating sequential-color Moon fields (left) to build simultaneous-color Earth fields (right)

Loading Moon Fields 1 & 2

(Disc Rotation 1 = Odd Earth Field; 2= Even Earth Field)
(On the table, time progresses downward. Horizontal processes occur simultaneously.)
Disc Rotation Track 1:
Red-Even
Track 2:
Blu-Odd
Track 3:
Grn-Even
Track 4:
Red-Odd
Track 5:
Blu-Even
Track 6:
Grn-Odd
1 Erase Play Back Shear-Play Back Play Back No Change Record
2 Record Erase Play Back Shear-Play Back Play Back No Change


Loading Moon Fields 3 & 4

(Disc Rotation 3 = Odd Earth Field; 4= Even Earth Field)
(On the table, time progresses downward. Horizontal processes occur simultaneously.)
Disc Rotation Track 1:
Red-Even
Track 2:
Blu-Odd
Track 3:
Grn-Even
Track 4:
Red-Odd
Track 5:
Blu-Even
Track 6:
Grn-Odd
3 No Change Record Erase Play Back Shear-Play Back Play Back
4 Play Back No Change Record Erase Play Back Shear-Play Back


Building Earth Frame 1

(Disc Rotation 5 = Odd Earth Field; 6= Even Earth Field)
(On the table, time progresses downward. Horizontal processes occur simultaneously.)
Disc Rotation Track 1:
Red-Even
Track 2:
Blu-Odd
Track 3:
Grn-Even
Track 4:
Red-Odd
Track 5:
Blu-Even
Track 6:
Grn-Odd
5 Shear-Play Back Play Back No Change Record Erase Play Back
6 Play Back Shear-Play Back Play Back No Change Record Erase
Loop back to “Disc Rotation 1”. Repeat steps until end of Moon data.


After the Disc Recorder

At Houston, the mooncam video underwent various electronic processes. The parallel output from the disc recorder fed to a standard color matrix (multiplexer) circuit. Next after the matrix came a proc (processing) amplifier. (Wetmore 20) NASA used stock equipment, probably by Grass Valley Group. (Wood 11) The matrix had three inputs, one for each color field signal. The matrix output standard NTSC signals. (Apollo Color Television Subsystem Operation and Training Manual 5-5, 5-6) These signals included...

  • A luminance signal (merged RBG fields)

  • In-phase-I and quadrature-Q, amplitude-modulated (QAM), suppressed carrier chroma. The I and Q signals defined the hue (phase)and saturation (intensity) for each primary color in the picture. The chroma bandwidth was one-eighth as detailed as the luminance (black-and-white) bandwidth.

  • The color burst signal, during horizontal blanking.

Diagram: Chroma signals, NTSC and PAL

Phasor diagram: Chroma signals, NTSC (US, Mexico, Canada, Japan, etc.) and PAL TV (Australia, most of Europe, etc.)

The proc amp provided...

  • New, stable horizontal and vertical sync

  • Stronger chroma signals (if necessary)

  • The sound subcarrier, mixing Moon and Earth chatter.

During transmission worldwide via satellite, each country converted the NTSC (U.S.) TV signals to the local format.



Color Fringes

Fringe “Benefit.” Apollo Moon pictures often had color fringes. Such fringes are a flaw of field-sequential scanning. Fringes resulted from unmatched content within neighboring Moon video fields. See photo, right. A mismatch would occur anytime an astronaut moved quickly. The color fringes persisted even after conversion to simultaneous color television (NTSC/PAL/SECAM).

What Viewers Saw. During motion sequences, such as an astronaut waving his arm, viewers noticed colored “trails.” For example, a moving arm would leave a momentary trail of arms: A red, a blue, and a green arm. A moment later, the “arms” would merge again, and appear as a single arm of natural color.

Right: Click picture to watch video of color fringes. (NASA video: Charlie Duke, during Moon surface EVA, Apollo 16. Source: Johnson)

Astronaut Charlie Duke with color fringes on arm

NASA photo


Reception on Earth Col-R-Tel Set

Earth Col-R-Tel TVs could have picked up Moon Col-R-Tel pictures. This reception method would require no NTSC conversion. Consider that downlink stations included Conrac studio monitors that engineers had modified for field-sequential operation. These Col-R-Tel-like monitors could directly receive the Moon, field-sequential telecast. (Wood 11)

Block diagram: Moon and Earth 
      Col-R-Tel converters cancel. Conclusion: Moon Col-R-Tel cameras can
      transmit directly to Earth Col-R-Tel TVs (Farbfernsehen, mechanisches 
      Fernsehen)

Converters cancel. The Col-R-Tel converter and moon-downlink converter canceled each other. Thus without NTSC in between the converters, neither converter would be necessary. The TV pictures would probably come in fine.

Experiment. Someone could prove my statement about Col-R-Tel Moon pictures. The experiment involves transmitting Moon pictures on a standard TV carrier. Then the experimenter would reproduce the unconverted Moon signal. The picture would appear on a Col-R-Tel unit without hue and saturation conversion electronics. Both the Moon and Earth units would maintain their disc-sychronization systems.

Cliff Benham has now performed this experiment, and it works! Cliff's homemade mooncam has reproduced color TV pictures on an original Col-R-Tel set. Since the camera pictures were field sequential, the Col-R-Tel converter worked barefoot! That is, without the adapter electronics. See... Homemade mooncam.

Graphic: Col-R-Tel Commutators. Top-Left: Hue points. Bottom-Left: Disc sync points. (Color Converter, Inc. 8)
Col-R-Tel commutators, schematic view. Top commutator points determine hue. Bottom
       commutator points keep disc colors in step with TV's vertical sync.

How the Standards Differed

Comparison. Below is a comparison of the Moon and Earth color standards vs. the CBS color standard. You can see how close Earth Col-R-Tel signals were to Moon Col-R-Tel signals. Note that both signals used the same vertical and horizontal frequencies. In both cases, the CBS system differed. This critical comparison underscores the statement that...

  • The CBS system didn't go to the Moon.

  • The CBS system couldn't lock a Moon TV signal.

Incidentally, this statement applies both before and after the downlink conversion. Either way, the CBS system was incompatible with Apollo color Moon pictures. On the other hand, Col-R-Tel borrowed extensively from both the CBS and NTSC color systems.


Standards Comparison

Spec Mooncam Col-R-Tel CBS NTSC
Vertical sync 60 Hz 60 Hz 144 Hz* 60 Hz
Horizontal sync 15,134 Hz 15,134 Hz 29,160 Hz 15,734 Hz
Horizontal lines 525 525 405 525
Color type Field-sequential Field-sequential Field-sequential Simultaneous
Color wheel wedges 6 6 6 0
Wheel scanning speed 600 rpm 600 rpm 1,440 rpm 0
Scanning order at tube RBG RBG RBG Simultaneous
3-color fields per second 20 20 48 60
3-color frames per second 10 10 24 30
Flicker Obvious Obvious Slight Usually invisible
Underlying monochrome signal NTSC NTSC CBS NTSC
*Note: Sometimes inaccurately reported as 180 Hz. This was the frequency of the CBS Chromacoder, a later development.

Two-Color Mooncam

Simpler Conversion. If Stanley Lebar had chosen a two-color system, he could have avoided using the disc-based converter. Two-color, field-sequential pictures transmit at the same frequency as normal NTSC does. That is, 30 frames per second. In terms of speed, this rate is a huge improvement over the three-color, field-sequential system that Apollo actually used. Recall that the three-color pictures transmitted at only 10 frames per second.

Still not live. Addition of NTSC signals such as the monochrome signal, chroma, and burst would still occur at the downlink. Also, Doppler correction would still be a requirement. Doppler correction involves a slight tape delay between two video recorders. This delay would remain. Yet two-color pictures could have been slightly closer to “live.”

Why go with three colors, then? Because by Newtonian theory, a three-color system has a broader gamut than does a two-color system. That is, the three-color system can display pictures with more colors and better color fidelity. By the way, Edwin Land would contest this statement. (Land, Experiments; Retinex) About the same time as the color Apollo flights, the Spectrac® TV color converter reinforced Land's point. (Benrey 45-47)

Art: U.S. flag

U.S. flag as it would appear on 2-color TV. The stripes are red-orange. The field is teal. Old Glory still looks fine! (Click button to compare 3-color flag.)


Photo: 1971 prototype 
       Spectrac converter
1971 Spectrac prototype, showing 2-color conver-sion. (Adaptation from Benrey 45)

Resolution. Another disadvantage of the two-color system is that frames transmit at half resolution. There is no odd and even field for each color. Instead, for each color, only one field transmits. As with Spectrac, probably nobody would notice the difference. (Topping patent 1967)

Which 2 colors? A typical two-color system displays orange and teal fields. A standard CRT makes the orange by turning on its red and green guns. To get teal, the CRT activates its blue and green guns. The result is much like the standard, NTSC chrominance I-signal. RCA engineers invented the I-signal because it is in the optimum color range for accurate flesh tones. The eye is more sensitive to flesh tones than to any other color.

Two-Color Mode. Early color TVs included a two-color mode using the high frequencies of the I-signal. Today, few if any TV sets can decode this mode. (Color Television: Simplified Theory 44-45)

One challenge for a two-color mooncam would be the U.S. flags that Apollo astronauts planted on the moon. Reproducing the white stripes and stars would be easy for such a two-color camera: Adding 100 percent orange and 100 percent teal produces white. But the camera's orange and teal axis is far away from either red or blue. What the camera would record would instead be dark red-orange and dark teal. From a reasonable distance, these colors would be fairly good stand-ins for red and blue. Take a look at our two-color flag (above). What do you think?

For more about two-color television, click TV in two colors.


Reference Links


General References About Mooncams

  • Apollo Lunar TV—Its History and Development from Armstrong to Leonov. Links to many Apollo mooncam articles. From Stanley Lebar, program manager who oversaw mooncam development at WEC.

  • NASA docs: More mooncam articles, manuals, and white papers. This is a more comprehensive collection than the above.

  • Video short: Stan Lebar with the Apollo TV cameras. See Lindsay, Honeysuckle Creek

  • Colin Mackellar, ed. “Honeysuckle Creek TV—Gene Cernan at Shorty Crater” https://vimeo.com. Accessed this site on June 30, 2019. URL: ttps://vimeo.com/55766658 Publication date: December 17, 2012
    Monochrome, 8mm movie off Conrac monitor. Engineers converted this monitor to display field-sequential color video from the Moon (apparently after Doppler correction). The movie shows flicker from the roriginal Moon transmission. One can also hear the Super-8 film advancing in the camera. At the Honeysuckle Creek downlink station, Ed von Renouard shot the original Super-8 film with a home movie camera. Colin Mackellar added the sound and painstakingly synchronized it to von Renouard's silent footage. The film documents Cernan's Apollo 17 moonwalk in December 1972.



Background Data: Space Program & Color TV


Alleged “Moon-Landing Hoax”




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