McMoon: How the Earliest Images of the Moon Were so Much Better than we Realised

Earthrise
An Earthrise over the moon’s horizon, taken by Lunar Orbiter 1 on August 24th 1966. Credit NASA/LOIRP.

Fifty years ago, 5 unmanned lunar orbiters circled the moon, taking extremely high resolution photos of the surface. They were trying to find the perfect landing site for the Apollo missions. They would be good enough to blow up to 40 x 54ft images that the astronauts would walk across looking for the great spot. After their use, the images were locked away from the public until after the bulk of the moon landings, as at the time they would have revealed the superior technology of the USA’s spy satellite cameras, which the orbiters cameras were designed from. The main worry was the USSR gaining valuable information about landing sites that the US wanted to use. In 1971 many of the images were released, but nowhere near to their potential quality, and mainly to an academic audience as public interest in the moon had waned. Up until 2008 most of the reported images from the project were the 1966 versions that were grainy and lower quality.

Earthrise difference
Comparison of the Earthrise image shown to the public in 1966 on top, and the restored image directly from the tape on the bottom. The bottom image was released in 2008, 42 years after it was taken. Credit: NASA/LOIRP.

These spacecraft were Lunar Orbiter I to V, and they were sent by NASA during 1966 and 67. In the late 1960’s, after the Apollo era, the data that came back on analog tapes was placed in storage in Maryland. In the mid 1980’s they were transferred to JPL, under the care of Nancy Evans, co-founder of the NASA Planetary Data System (PDS). The tapes were moved around for many years, until Nancy found Dennis Wingo and Keith Cowing. They decided they needed to be digitised for future generations, and brought them to NASA Ames Research Centre. They set up shop in an abandoned McDonalds, offered to them as free space. They christened the place McMoon. The aim was to digitise these tapes before the technology used to read them disappeared, or the tapes destroyed.

The Mcdonalds
The McDonalds nicknamed McMoon, with the trademark skull and crossbones flag denoting the “hacker” methodology. Credit: MIT Technology Review.

The Lunar Orbiters never returned to Earth with the imagery. Instead, the Orbiter developed the 70mm film (yes film) and then raster scanned the negatives with a 5 micron spot (200 lines/mm resolution) and beamed the data back to Earth using lossless analog compression, which was yet to actually be patented by anyone. Three ground stations on earth, one of which was in Madrid, another in Australia and the other in California recieved the signals and recorded them. The transmissions were recorded on to magnetic tape. The tapes needed Ampex FR-900 drives to read them, a refrigerator sized device that cost $300,000 to buy new in the 1960’s.

FR-900
The FR-900 that was used to restore the old images. A mix of old and new equipment to get the images to modern PC’s. Credit: MIT Technology Review.
FR-900 signed
The back of the first FR-900 has been signed by the people who brought the project to life, including Nancy Evans. Credit: MIT Technology Review.

The tape drive that they found first had to be restored, beginning with a wash in the former restaurants sink. The machine needed a custom built demodulator to extract the image, an analog to digital converter, and a monitor connection to view what was happening. As the labelling system of the tapes had been forgotten, and documentation was not readily available, they had to hand decode the coordinates on the tapes. They also had a big collection from parts of other FR-900’s and similar designs. The spare parts were constantly needed to keep the recorder going, there was good reason that the format didn’t continue for long.

moon image reels
These are just some of the reels of moon images. They use this machine to hand inspect the reels, mainly to figure out the coordinate labelling system. Credit: MIT Technology Review.

In order to read the tapes, the heads of the FR-900 apply a magnetic field to the tape inducing a current through it. The current can be measured and run through the demodulator. This pulls out the image signal, that is then run through an analog to digital converter. The data is then processed on a computer using the custom system they set up. They made custom software that interfaced with Photoshop to link the relevant parts of the image together. The orbiters sent out each image in multiple transmissions, with each strip (one tin) making up part of the image. the software manages to link up the images nearly seamlessly at the full potential resolution. The best of the images can show the lunar surface at a resolution less than 1m, much better than any other orbiter that has been there.

tapes tapes tapes
The image shows the sheer amount of tapes that the few images are stored on. Inside McMoon you can also see a sleeping bag some poor guy had to stay in. Credit: thelivingmoon.com.

They were huge files, even by today’s standards. One of the later images can be as big as 2GB on a modern PC, with photos on top resolution DSLRs only being in the region of 60MB you can see how big these images are. One engineer said you could blow the images up to the size of a billboard without losing any quality. When the initial NASA engineers printed off these images, they had to hang them in a church because they were so big. The below images show some idea of the scale of these images. Each individual image when printed out was 1.58m by 0.4m.

NASA printing
This image shows the large thin strip images being laid out on the floor of a large room so the engineers could look for good landing spots. Credit: NASA.
NASA Engineer
The image shows a NASA technician with a ream of photograph printouts used to assemble the overall image. Credit: NASA.

Orbiter IV was there to produce a single big image of the front side of the moon. In pictures taken between May 11-25, 1967 the Orbiter took a number of images that span the area from the north pole to the south pole and from the eastern limb to the western limb. The complete mosaic of an image stretched 40 by 45 ft. The engineers laid it out on the floor and all the observers including the astronauts had to crawl over it and take off their shoes. The images were so good, even at this size that some astronomers used magnifying glasses. This giant image was the primary source to select the sites for Orbiter V  to photograph in a higher resolution. The images taken by Orbiter V decided the exact locations for Apollo 11 to land.

Tsiolkovskiy Crater
The very prominent feature in this image is the Tsiolkovskiy Crater on the far side of the moon. Taken by Orbiter 3 on 19 February 1967. Credit: NASA/LOIRP.

Since 2007 the Lunar Orbiter Image Recovery Project has brought back 2000 images from 1500 analog tapes. The first ever picture of an earthrise. As Keith Cowing said “an image taken a quarter of a fucking million miles away in 1966. The Beatles were warming up to play Shea Stadium at the moment it was being taken.” To find more of those images go to their website, but I warn you those images are huge.

Thank You for reading, take a look at my other posts if you are interested in space or electronics, or follow me on Twitter to get updates on projects I am currently working on.


78 thoughts on “McMoon: How the Earliest Images of the Moon Were so Much Better than we Realised”

    1. Totally agree, mistake on my part. The context of the number is just to give a general guideline of how huge the images produced are compared to something people can relate to.

          1. Still, top resolution DSLRs were 10MB in 2007-ish. Now it’s at around 60MB. I know it’s a small detail and not the point of the article, but please don’t spread misinformation, thanks.

          2. When you say 60MB is an uncompressed high res image for a modern camera, can one compare that with 2GB (or GiB?!) raw digitized film for one orbiter picture? Then an analogue cam + a photolab + digitizer like on lunar orbiter would kick 52 years advanced digicams out of saturns rings.

      1. Ryan….

        This is Dennis Wingo, co-founder of the LOIRP project.

        A medium resolution LOIRP image is about 700 megabytes. A High resolution image, broken into three parts is over 2 gigabytes…

    1. lol right… Small typo in rhetorical “banana for scale” statement and out come the pitch forks.

      Enjoyed the read as well. Any job openings at McMoon?

    2. I have more of a problem that he used “costed.” The past tense of “cost” is “cost.” There is no such word as “costed.”

      1. This website has good information about the word “costed” at http://grammarist.com/usage/costed/ .
        Examples:
        1. Today milk costs $4.10 a gallon. (present tense)
        In 1995 milk cost $2.95 a gallon. (past tense)

        2. Today milk is costed (priced) at $4.10 a gallon. (present tense)
        In 1995 milk was costed (priced) at $2.95 a gallon. (past tense)

    3. Liam said exactly what I was thinking. I couldn’t have put it better. Photography and parenting “mistakes” will send any comment section to the 5th circle of hell.

  1. “Instead, the Orbiter […] beamed the data back to Earth using lossless analog compression, which was yet to actually be patented by anyone.”
    Any details on the method used?
    Could this be used as prior art to revoke some patents ?

    1. I don’t know have any further detail of the method of transmission yet. That being said I am looking to do a follow up with a more detailed and slightly more technical overview of the camera and the Lunar Orbiter.

        1. Dennis- Glad this labor of love is coming to light. I caught the exhibit opening a couple of years ago at the New Museum in Los Gatos. I do think Nancy Evans’ role in saving the tapes and one-of-a-kind tape machine can’t be overemphasized. If not for that backstory there would have been no McMoon project. Cheers.

    2. It used a method called vestigial sideband where a precise (1hz) people lot tone was used as a means to allow the stripping away of one half the waveform and then using that tone on the other end to reconstitute the missing side band. It is still used in communications today.

      1. “People lot tone”… I love autocorrect! 🙂

        Thank-you Dennis, to you and your team. It would have been a tragedy to loose these historic images.

        1. So… cheeky ans funny as your answers may be, if the proper term isn’t “people lot tone”, which is it then? 😛

  2. Wonder how the (east german) MKF_6 that the russians used compares to this (the optical part, the MKF_6 films where brought back to earth, no digitalisation/transmission there)

      1. Exceptionally hard in the 1960’s to bring the film back. I would estimate that 95+ percent of the fidelity of the original images were retained in the ground station tapes that we digitized. We worked with the tape data in a “predemodulated” format, meaning that the original radio waves from the spacecraft ( frequency shifted to a 10 MHz IF frequency) were recorded on tape. It does not get any better than that!

        1. It’s beyond AMAZING that necessity sparked such fantastic innovation. I look forward to enjoying some of these images.
          That was indeed a great read.

    1. They really would, I especially like the earthrise picture! All the images are available online, there may be slightly lower resolution versions that would be more suitable as a wallpaper.

          1. There used to be a wall sized poster (many sheets together) of earthrise from the surface of the moon. I bought mine about 40 years ago from The Smithsonian gift shop.

  3. It fascinates me how engineers of that era were able to bootstrap a digital imaging system with no “computer” support as we understand it today. The concept of line by line digitization of film negatives for the movie industry was not commercially available until 20 years later (from memory) yet they did it in orbit and processed film as well. The 20th century truly had some great minds. Are we that clever today or do we simply stand of the shoulders of these giants?

    1. It was used in television from the 70’s at least, but obviously at much lower resolution (in the region of 640 x 480 pixels per frame) and machines the size of three 19″ racks sucking large amounts of power, to broadcast and record film, making this satellite based process even more incredible.

    2. I seem to recall basic line scanning (or at least, the concept of it), was already used to transmit crude images through the telegraph system for newspapers.

  4. “After their use, the images were locked away from the public, as at the time they would have revealed the superior technology of the USA’s spy satellite cameras, which the orbiters cameras were designed from. Instead the images from that time were grainy and low resolution, made to be so by NASA.”

    Where is the evidence to support this?

    The camera was designed by Eastman Kodak, see: https://www.youtube.com/watch?v=7HRF8rQD1Vw and when the orbiter sent back the data in 1966, the technology did not exist to produce a full-resolution image so for decades, images existed as a grainy black-and-white photos. More than forty years later, NASA recreated the image from the original data, producing for the first time a high-resolution view of the Moon and Earth from the Lunar Orbiter Missions. The image was released on November 13, 2008. See: https://earthobservatory.nasa.gov/IOTD/view.php?id=35906.

    To say that ” the images were locked away from the public, as at the time they would have revealed the superior technology of the USA’s spy satellite cameras ” is a little bit of journalistic license, don’t you feel?

    1. Well they didn’t release the images in their true form to the public and just stored them away. They had the technology to print them out at maximum resolution and walk around on them. True they didn’t have the technology to make the digital images smaller but they could have easily released a much much higher quality image than they did if they wanted to. I understand what you are saying, and I appreciate the comment but I don’t think I have stretched the truth.

      1. Considering that the method described here (image into film, develop film, scan with tv camera and radio data back to earth) was exactly how the USAF originally designed its SAMOS observation satellite, they were probably directly responsible for a lot of the system design. And in the 1960s spy satellite stuff was still impossibly classified–like, *weather* satellites were classified because they supported spy sat operatjons!–so it’s not at all strange that these photos would have to be intentionally degraded before public release.

      2. WRT “they could have easily released a much much higher quality image than they did if they wanted to.” No they could not. If NASA could have released higher res imagery (which they did not have) then why would they have gone to the absurd length of printing huge things on paper for internal use? Keith Cowing Co-lead LOIRP

        1. Keith: I think he meant that they had the technical means to release a higher res version than what they did – but they probably did not have the authorization to do so.

  5. totally incredible – i had no idea this scanning tech existed back then or the mag tape size either – I worked on scitex systems back in the very early 90s and a 90 megabyte Mag tape was considered state of the art the Hell and cross field scanners the imaging manipulation system and the tape drives were all told around half a million, i thought this was the highest end stuff out then ! so to see these 2 gig images on tape drives that a could hold them transmitted from the moon and scanned at 200 lines per millimeter is AMAZING ! thanks for the article
    PS Dennis Wingo very cool that a you are participating in this discussion
    PPS – the guy on the ladder is AIRBRUSHING that moon pic probably exaggerating hilite and shadow detail

    1. The 2GB image is from digitizing the analog signal on the tape (slightly) beyond its actual capacity for information (ie some of the data is noise or redundant). In an analog image like the above it is perfectly acceptable if, when you digitize the image one time you get a level of “25” and the next you get a level of “22” (and the original might have been something different at that moment of recording but it was never actually quantized because it was analog). If you wanted to use this for lossless digital data (where no bits can be compromised) you would instead want to use frequencies and quantized signal levels well below the noise threshold of your recording medium and in addition add parity/error checking bits.

  6. Great article and great “ressurection job”on the recovery from tapes.

    This whole thing would,make an awesome subreddit under IAmA or such…

  7. When thousands of the most able brains were put to the business of just sending a few people off our world to another and bringing them back alive (instead of prosecuting war), the ingenuity used and the sheer quality of results is staggering. Even the tedious problem of developing film in zero gravity, then scanning it, all fully automatically with 60s technology, is really impressive. I’m sure I didn’t have that number of developing marks on my negatives back then, but these photos trump mine any day.

    1. My father, Dr. Leonard W. Tregillus led the technical team at Eastman Kodak Research Labs, in a section called Emulsion Research, that under contract to NASA, developed the Bimat transfer process used to develop film in lunar orbit. Our house was full of moon pictures before 1968. He also told me that the same process had military applications in Southeast Asia, operating out of Air Force bases in Thailand. The film was developed before the F-111 return to base. He had a small unit which we used at home to develop tri-x film, with a developed negative and positive film strip. The image restoration program is awesome!

  8. NASA was apparently able to use these extremely detailed photographs of the moon to build the large plaster three dimensional models of the moon that they used to shoot some of the special effects for the Apollo missions, for shots where the lunar module appears to be circumnavigating the moon as well as shots of it appearing to land on the moon. VERY cool.

  9. Awe inspiring. Humbling. Amazing. My elders did this. I crawled around on the carpet hoping for another arrowroot biscuit while this was happpening. A gorgeous example of the wonder of man when we take our eyes off eachother and lift them instead to the skies. Humans need more: because this.

  10. Fascinating stuff. Thanks for writing this. The research must have been a lot of fun. It is stunning to me how expensive computer hardware was (and I assume the software too in terms of how few licenses there must have been and the associated development costs).

    Great article! Good work.

  11. It is good,
    I cannot help but wonder where it all went wrong. Being able to put a man on the moon and take him back to earth,,,alive.Incredible, Fantastic but that was the peak achievement I am afraid.
    Thousands of refugee children have been separated from their parents on the Mexican border deliberately. The commander in chief of the USA has told Abe that he can give him 25 million Mexicans. He has launched trade wars all around the globe. Trade wars are good he says.N Korea is now safe he says.
    What went wrong folks, ?
    George,

    1. Which has been law and procedure for some time now, but has curiously becomr an issue only AFTER the current occupant of the White House took over. Oh– and thank you for bringing absolutely untelated politicking and virtue signaling into what was a perfectly good scientific discussion.

  12. The US operated a reconnaissance satellite program beginning in the late 1950s known by the code name “Corona”. It was highly classified at the time but used very high-resolution film cameras to photograph areas of the earth in which the US Intelligence agencies had an interest. The film was spooled into a capsule (later two per satellite) that was ejected from the satellite, re-entered earth’s atmosphere, and was recovered mid-air by special capture aircraft. The Corona program was not declassified until 1992. Later satellites, beginning with the famous KH-11, used electro-optical systems to produce digital images. The capability of the satellite was inadvertently (at least partly) revealed by a photograph published by Jane’s in 1984 that showed a Kiev-class aircraft carrier under construction. Digital detectors of the resolution NASA deemed necessary for the lunar photographs did not exist at the time, so scanning film was a way to get the resolution needed without having to return the film itself. The Corona program did it, but from earth orbit, not lunar orbit. I am very glad that these photographs were saved (unlike some of the Apollo 11 landing slow-scan video; the tapes on which it was recorded were over-written when the tapes were supposedly erased and re-used).

  13. Absolutely astonishing photos, the tech involved to take and process them in orbit, scan them, send the information back, and print such huge prints at a time I was still at school is unbelievable. Mind truly blown!
    I worked in print pre-press for a time, around 1995, and I was trained to use a Crosfield 6250 drum scanner with Mac interface, and I used to scan transparencies and prints at 300dpi, then clean up and retouch in Photoshop, those images were roughly 40-50Mb, for reproduction up to A4, sometimes A3; the size of the images printed off from the orbiter’s scans are beyond what most would consider practical today, apart from those huge coverings put up on building developments, and I doubt the resolution of those is much more than I was producing twenty-odd years ago.
    Thanks to everyone involved in recovering these historically important images for everyone to enjoy.

  14. Exceptionally fascinating story including the efforts and dedication of the staff who recovered and digitized the information. Now, if they could only find the original moon landing tapes…

  15. Okay, since others have started the grammar/usage pedantry, I’ll chime in:

    No apostrophes needed when pluralizing numbers (“1960s” not “1960’s”). But “restaurants sink” needs one because it’s a possessive.

    1. As a budding grammar Nazi myself let me advise not to confuse rules with style.

      The apostrophe in restaurant’s sink is a rule. The apostrophe in 19060s versus 1960’s is a style.

      Solider on, ever vigilant !

  16. MegaByte Schmegabyte, this isn’t a scientific paper, it’s a testimony to Homo Habilus.

    “Unsung heros” sounds like a cliche’, but how else do we describe these folks who go to work everyday just to advance our knowledge of our world? Neil Armstrong was standing on their shoulders.

    Thanks

  17. I sit here in stunned amazement pondering the series of events and actions and coordinations of people that made this happen. When the human brain focuses on a desire to achieve a result and then achieves that result is truly magic. Merging of old and new technology. Just truly astounding stuff. My deepest respect to those that achieved this. My most fervent wish is that minds like these can be focused on the many other problems of the world.

  18. I paid several visits to McMoons during this amazing project, and was taken back by the sheer complexity of what they had to do. The FR900 is basically a insturmentation version of a quadruplex videotape recorder. It used the same heads, required a vacuum guide to hold the tape in the correct position, and required new bearing be made to some incredible precision. The signal recover process was once highly classified, and that apparently had a page of equations and a block diagram to work from. Brilliant signal system engineer Al Stern, formerly of Ampex, designed a digital approximation of the original analog signal system that apparently worked on the first try. Although my involvement with the project was very trivial, it was something I will always remember.

  19. To my eye it looks as though the “NASA technician with a ream of photograph printouts used to assemble the overall image” (caption) has an airbrush in his hand, and is airbrushing a larger mural based on the smaller printouts. Was the larger mural then photographed again? What’s going on here?

    Wonderful article. I’ve been considering film processing baths in orbit / zero-g, which is an incredible achievement. Those “reels of moon images” (caption) look like they’re 35mm in size, not 70mm, as described in the article. Are they different?

  20. Fantastic seeing this article bring folks out of the proverbial woodwork to share other stories.

    Dennis, out of curiosity, how long did it take the orbiters to transmit that much data ? Seems like comms in those days were so low-bandwidth it must have been slower than the (much lower res) Pluto images coming back gradually.

  21. P.s. ‘Schoole’ is not spelt like that. It’s ‘School’ so before you come at someone else, make sure you ‘fix your writing’ first.

  22. The resolution of the lunar orbiter images was quite amazing. A rough calculation indicates the size of each three part high resolution Lunar Orbiter image. If the the 70 mm film was scanned at a resoluition of 200 spots per millimeter and the image area was about 65 mm wide then the image had about 13,000 spots across a frame. Note all the imaging system was fundimentally analogue so I use the term “spot” rather than pixel. The three parthigh resolution frame had proportions of about 3.75 x 1 (15×4) suggesting approximately the data had approximately had about 634×10^6 spots in each high resolution frame.

  23. This is a great article about an awe-inspiring effort (as was everything about Apollo). Thank you Nancy, Dennis and Keith for taking it on!

    And since we’re being pedantic, I’ll point out that the description of reading magnetic tapes is slightly… confused. When the tape is recorded the magnetic field at the heads magnetizes (reorients) particles on the tape. When it’s played back the magnetized particles passing by the heads induce a current in the heads, which is then amplified, demodulated, etc.

    As for the analog compression, that was about saving bandwidth in transmission between the orbiter and earth, not about compressing the image itself.

  24. While this article was entirely a wonderful and highly informative read, one mystery remains: how on earth does one abandon a McDonald’s?

  25. Thanks for a fascinating story! One thing I don’t understand: in 1966, how did they produce prints that would maintain the high resolution from the signals received back from Orbiter? It doesn’t seem like the printers of the day would be up to the task, so did they recreate a negative and use a photographic process?

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