The thousand-ring circus

On the 50th anniversary of Apollo 11, I thought readers might get a kick out of seeing this funny 1968 memo regarding a problem that needed to be fixed in the Lunar Module (it was), and learning about its extraordinary author, NASA engineer Howard W. “Bill” Tindall, Jr. I wrote about this memo five years ago with just a little information on Tindall, but I wanted to expand on that a fair amount this week because without his efforts, I’m pretty certain we would not have reached the moon before that decade was out.

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I first learned of Tindall in 1989 when I read Apollo: The Race to the Moon by Murray and Cox, which I think will ever remain the definitive Apollo history from the perspective of technical people on the ground, and have since gathered the information that’s included here from 1,700 pages of his memos that the Kennedy Space Center History Office sent to me in 1999, individual memos kindly provided by the University of Houston-Clear Lake from their Johnson Space Center History Collection, some JSC oral histories, and several other books and online resources.

After his earlier work on Mercury trajectories and Gemini rendezvous techniques, Bill Tindall’s parchment-dry title was “Chief, Apollo Data Priority Coordination,” a position created by Apollo Program chief George Low that quite unusually cut across several branches of the Manned Spacecraft Center in Houston. Tindall worked with design engineers, contractors, mathematicians, programmers, mission controllers, and astronauts – everyone, really – to develop and hone the dozens of mission techniques that were used in each one of the twelve distinct phases of lunar missions. Guidance flight controller Steve Bales said of Tindall, “He had a thousand-ring circus going all the time.”

Flight Director Gene Kranz: “Tindall was pretty much the architect for all of the techniques that we used to go down to the surface of the moon. Tindall was the guy who put all the pieces together, and all we did is execute them. If there should have been a plaque left on the moon for somebody in Mission Control or Flight Control, it should have been for Bill Tindall. I respected Bill so much that when the time came for the [Apollo 11] lunar landing, the day of the lunar landing, I saw him up in the viewing room, and I told him to come on down and sit in the console with me for the landing. He didn’t want to come down, but I cleared everybody away and we had Bill Tindall there for landing, and I think that was probably the happiest day of his life. A spectacular guy.”

Late last month, the Johnson Space Center re-opened the painstakingly and beautifully restored Apollo-era Mission Operations Control Room, MOCR 2: https://arstechnica.com/science/2019/06/behind-the-scenes-at-nasas-newly-restored-historic-apollo-mission-control/. How that restoration came about is discussed in detail by JSC Historic Preservation Officer Sandra Tetley and contractor lead Adam Graves in this hour-long episode of “Houston We Have a Podcast”: https://www.nasa.gov/johnson/HWHAP/restoring-the-apollo-mission-control-center

Tindall’s frequent memos – usually two to four a week – were all dictated because Patsy Saur, his secretary, said he’d better learn how because she was not going to lose her shorthand proficiency. They were called Tindallgrams by those who eagerly awaited their common sense, humor, and perfect condensations of discussions and decisions made during the meetings he conducted. Some of those meetings went on for two or three twelve-hour days, with anywhere from half a dozen to a hundred people in the conference room discussing – or, sometimes, shouting and arguing vehemently – and coming to a consensus on every item on the agenda – or, sometimes, accepting Tindall’s final decisions via Tindallgram. Tindall, Buzz Aldrin’s equal in orbital mechanics (Aldrin’s MIT doctoral thesis was “Line-of-Sight Guidance Techniques for Manned Orbital Rendezvous”), once estimated that he spent just 10 to 20% of his time on standard mission techniques and the rest developing finely-detailed “what if” contingency plans, many of which were never needed but some of which came in very handy indeed. The increased peace of mind I’m sure he had as a result was no doubt shared by many because they all knew that there was a precise plan for just about any problem imaginable.

They were after what was right, and everybody was passionate about it. Everybody was young so they were kind of brash and there wasn’t a lot of patience anywhere. So some of those meetings were very, very colorful. Some of the characters were colorful. At the end of this, you were just inundated with all of this stuff you’ve heard. And now what?

And the next day you would get this two-, maybe three-page memorandum from Bill Tindall written in a folksy style, saying, ‘You know, we had this meeting yesterday. We were trying to ask this. If I heard you right, here’s what I think you said and here’s what I think we should do.’ And he could summarize these complex technical and human issues and put it down in a readable style that – I mean, people waited for the next Tindallgram. That was like waiting for the newspaper in the morning. They looked forward to it. I just remember that I’ve always talked to people about this amazing skill.

– Ken Mattingly, Command Module Pilot, Apollo 16

Just how complicated could Tindall’s mission techniques get? Consider that Apollo 11 Command Module Pilot Mike Collins put this CMP Solo Book on a string around his neck a few hours before Armstrong and Aldrin departed for the lunar surface (onboard audio: “Neil, I hate to bother you; could you get my solo book out of R-1 there? Big frapping book, with a bunch of updates on the cover.”). Starting on page 60 are summarized procedures – cheat sheets, if you will – for eighteen different Lunar Module rescue scenarios that Collins might have to execute if his crewmates “never made it to the lunar surface, or if they got there early or late, or departed crooked or straight” (Collins in Carrying the Fire). Some involved Collins diving the 32-ton Command-Service Module from its 60-nautical-mile lunar orbit to as low as they dared – possibly down to 35,000 feet, but I think they would have been a tad more conservative – in order to catch up to the LM if its orbit was higher and slower than the CSM’s, an example of how counter-intuitive orbital mechanics can be.

Here’s a YouTube link to an MIT “Engineering Apollo” class with the sharp and funny Collins in 2015. The interviewer/presenter is Professor David Mindell, the author of Digital Apollo.

Tindall also kept up with the latest scuttlebutt, which at times required that he step in to protect things that needed protecting. For example, when he heard that a NASA high mucky-muck said they should get rid of the Lunar Module’s rendezvous radar to save weight, and that people were beginning to take the idea seriously, Tindall took action to nip that in the bud immediately by writing this memo to George Low, the boss of all Apollo bosses. He didn’t name the official in the memo, but it was Associate Administrator for Manned Space George Mueller who made the flippant suggestion after a visit to Grumman on Long Island, where LM weight reduction was a constant focus for years. After Low read Tindall’s high-energy memo, some memos went between higher mucky-mucks and a few weeks later Mueller’s boss told him, in summary, “Yeah…no.

Sometimes fairly unlikely scenarios gnawed at him a bit – such as whether their re-entry targeting was so good that a Command Module might, by mistake and with a catastrophic result, hit the aircraft carrier that was waiting for its splashdown. His method of dealing with small worries was the same as the large ones: address all eventualities completely through thorough planning. In this case, his memo titled Let’s move the recovery forces a little. (“PAO requirements for good commercial TV” refers to the NASA Public Affairs Office.)

Another of the 1,000+ Apollo memos Tindall wrote from 1966 to 1970 was on the topic of why Apollo 11’s Eagle overshot its intended landing site by four miles. It described how incomplete venting (that is, depressurization) of the docking tunnel prior to undocking caused the Lunar Module to pop like a cork off the Command Module with just a little extra velocity, which in turn caused significant changes in its descent profile. A new rule for subsequent missions required that Mission Control confirm complete depressurization of the tunnel. A related Tindallgram on other venting sources adversely affecting the descent trajectory was titled Vent bent descent, lament!, and he wasn’t shy about making his strong feelings on those vexing vents known to all the top brass at NASA, including chief spacecraft designer – also a culprit – Max Faget, in an unusually all-caps-titled VENTS (“This will either amuse you, waste your time, or just possibly accomplish something great.”)

After a three-day-long “Mission Techniques free-for-all” not even two weeks after Apollo 11, he wrote How to land next to a Surveyor – a short novel for do-it-yourselfers. That and a follow-up memo, in which he revised his previously pessimistic targeting prognosis, detailed new mission techniques that were key to Apollo 12 Commander Pete Conrad being able to set Intrepid down just 535 feet from the Surveyor 3 spacecraft that had, two-and-a-half years earlier, soft-landed on the Ocean of Storms after bouncing twice due to a slightly-too-early engine shutdown.

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Such pinpoint accuracy was life-critical for later landings, in particular Apollo 17, which landed in the Taurus-Littrow Valley, a box canyon surrounded by mountains on three sides.

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Here’s an excellent 2015 Apollo 17 documentary in two parts: https://www.youtube.com/watch?v=vIGbOoZzlYI https://www.youtube.com/watch?v=SQOEC9gHpmA

Oh, yeah…for a period of about a year in 1966-67, Tindall, who grew up in Scituate, Massachusetts, flew up to Cambridge from Houston for two or three days every week to help organize, focus, and speed up – effectively manage, sometimes in a blunt manner – the MIT Instrumentation Lab’s previously somewhat free-form development of the COLOSSUS and LUMINARY software for the Apollo Guidance Computers (AGC) in the Command and Lunar Modules, respectively. (He visited often enough that he sent out a TripAdvisor-style memo every now and then.)

Early on, Lab engineers reported, to Tindall’s great alarm, that the Command Module code was about 30,000 bytes in excess of the 72,000 available in the AGC and the Lunar Module software was around 10,000 over its 72,000. 13 October 1966, the day Tindall directed them, in person, to eliminate much duplicated code that he had found, and to cut several elegant but non-essential and hence memory-wasting routines, became known to those in the Instrumentation Lab as “Black Friday.” Two weeks after Black Friday, he discussed his strategy in this memo, which began with the important point that “There are a number of us who feel that the computer programs for the Apollo spacecraft will soon become the most pacing item for the Apollo flights.” Despite the initial hard feelings at the Lab, they did what he asked, and over time came to realize just how beneficial his involvement was to their work – and best of all, that work was ready when it needed to be.

Here’s a profile of Margaret Hamilton, who, two years after the Lab’s early difficulties, became leader of the Apollo spacecraft software development effort: https://www.smithsonianmag.com/smithsonian-institution/margaret-hamilton-led-nasa-software-team-landed-astronauts-moon-180971575/

In late 1965 just before his work on Apollo began, the New York Times profiled Tindall in a brief Gemini 6/7 sidebar titled “Rendezvous Planner Howard W. Tindall, Jr.” (reprinted in the January 1966 Brown Alumni Monthly here), but Charles Fishman, who contacted me while researching his new book, One Giant Leap: The Impossible Mission That Flew Us to the Moon, says that when Tindall died in 1995, not one newspaper in the US ran an obituary. It’s even difficult to find any photographs of him bigger than a postage stamp, but here are a couple: below, one in his office (a screenshot from episode 3 of the also excellent “Moon Machines” series, playlist here: https://www.youtube.com/playlist?list=PLTu8nanTJo7GvulBxz9JT9JcXeXimM1Vr) and he’s in the center of this photo taken during Apollo 13, chin in hand, looking at papers – some probably written by him.

I’ve always thought that more people ought to know about this remarkable man. To paraphrase him, if you are still with me, hardy reader, now you do.

Bill Tindall; click for a larger version

I think it’s safe to say he thoroughly disliked inaccuracy and inexactitude, which may be reflected in the “H. Timdell” [sic] name I noticed taped to the wall behind him in that photo, the misspelling perhaps from some conference he attended. I’ve no evidence for it, but I like to think he kept it up there to point out to visitors at appropriate moments, maybe with a raised eyebrow and a little flourish of sarcasm.

We’d all get in there and defend our [computer] requirements, and then Tindall would cut them. And then we’d cuss him. And Tindall would grin, and cuss back, and laugh his loud, infectious laugh, and keep right on going.

– Apollo Flight Director Cliff Charlesworth

We weren’t working overtime, we were playing!

– Bill Tindall

Edited 9 August 2019 to add: My theory above about that misspelling on his wall is now inoperative…defunct…shot down. The Johnson Space Center History Office has kindly found and sent me the original of that official photo along with nine others of Tindall from 1965-1979, which I’ve just posted here: https://finleyquality.net/The-ringmaster. Some deductive reasoning on the uncropped version of that one that they sent reveals the much more likely source of “H. Timdell” [sic].

Edited 21 August 2019 to add: I just happened upon this tidbit while reading Harrison Schmitt’s 1999 Johnson Space Center oral history interview. Twenty-seven years after his Apollo 17 mission, Schmitt emphasized how important Tindall’s memos were, not just at the time but for purposes of mission planning in the future (emphasis mine):

Well, Frank Borman approached me, asked me if I would do the lunar orbit flight planning for their effort. And that meant that I began to interact with [Howard W.] Tindall’s group, the Flight Operations Planning group that met weekly that really was the focus of all of the operational planning for a particular mission. They were looking at all the missions, but the one up was the one they were concentrating on. And that’s another tremendous resource.

And I’m not sure where there is a complete collection of what were called Tindallgrams. They were his summary of each of those meetings. I have a partial collection at the University of New Mexico in the files there. Whether there would be a complete collection or not, I don’t know. But somebody ought to make a very, very specific effort to get a complete collection of the FOP minutes, Tindallgrams, and to get those in some kind of form and bound. Because that is a resource that should not be lost. I can understand it’s hard to put together. I hope somebody has been able to do that.

Cinnamon tree just out of range

Chang’e 4 (left arrow) and its rover captured by the Lunar Reconnaissance Orbiter Camera on 8 February

The source LROC article is here. As to the title: The Chang’e lander is named after the goddess of the moon and the rover, Yutu 2, takes its name from the large jade rabbit said to accompany her. Both were mentioned as Apollo 11 orbited the moon prior to landing. From the mission transcript:

095:17:28 Capcom Ron Evans: Roger. Among the large headlines concerning Apollo this morning is one asking that you watch for a lovely girl with a big rabbit. An ancient legend says a beautiful Chinese girl called Chang-O has been living there for 4,000 years. It seems she was banished to the Moon because she stole the pill of immortality from her husband. You might also look for her companion, a large Chinese rabbit, who is easy to spot since he is always standing on his hind feet in the shade of a cinnamon tree. The name of the rabbit is not reported.

[Chang-O is also spelled Ch’ang O and, in the more modern rendition, Chang’e. Chang’e was subsequently adopted as the name of the Chinese unmanned lunar exploration programme, the first spacecraft of which was launched in 2007. The third in the series, Chang’e 3, was the first to land which it did autonomously on 14 December 2013 in Mare Imbrium. The rabbit’s name of Yutu, stated by Evans as not reported, was given as the name of the first Chinese lunar rover, delivered to the surface by Chang’e 3 and it translates to ‘Jade Rabbit’.]

095:18:15 CMP Michael Collins: Okay. We’ll keep a close eye out for the bunny girl.

Chang’e

Update 2 May 2019: Much closer Lunar Reconnaissance Orbiter views can now be seen in the LROC posts Above the Landing Site and Chang’e 4 Rover on the Move

The Surveyor landers would be jealous

Here’s some beautiful descent footage from the Chang’e-4 spacecraft that made the first ever soft landing on the far side of the moon last week. When it rotated quickly toward the surface at 1:01, I found myself instinctively saying with a grin, “Pitchover!” I’d suggest viewing this full-screen.

Here’s the descent profile you’re seeing in that video:

Beijing Aerospace Command and Control Centre

The Lunar Reconnaissance Orbiter team have determined where Chang’e-4 touched down, its approximate position in the Von Kármán crater shown in the older LRO imagery of the area below. LRO will next pass over the Chang’e-4 site toward the end of this month, when they ought to be able to snap a picture of the lander on the surface. Depending on LRO’s altitude at the time, it will show up as anything from a few bright pixels – remember that it’s just the far side and not a dark side – to something showing a bit more detail of the lander, the rover, and perhaps its tracks.

NASA/GSFC/Arizona State University

First full panorama released of the landing site, produced from 80 images:

“Yeah, sure, high-def landing video, but does it bounce? I thought not.” – Surveyor 3

Okay, so the descent engine didn’t cut off at the right altitude, but that new one still can’t bounce.

All you really need to know about the term

From Sky & Telescope:

“Astrologer Richard Nolle first coined the term supermoon in a 1979 issue of Dell Horoscope magazine.”

If I recall correctly, Dell Horoscope was found almost exclusively at supermarket checkouts, next to the National Enquirer and Weekly World News, the latter of which featured cover stories such as WORLD WAR 2 BOMBER FOUND ON THE MOON! and MOON TO EXPLODE IN 6 MONTHS! and – possibly a tie-in with Dell Horoscope – MOON DRIFTING TOWARD EARTH!

Today’s headlines are almost as silly:

  1. Keep eyes open
  2. Look up – chances better at night
  3. Will be mysteriously invisible if cloudy
  4. Will appear slightly larger than usual if not

Edited to add: This post is a few years old, but everything still applies. The cut of his jib? Admirable.

New digs

We moved our offices into a new building a couple towns away this week, and I ended up with a substantially larger office – “All the more to decorate” thought I, rubbing my hands. A gallery of my new digs is below. I haven’t decided yet how to fill out one wall, but the other walls are pretty much as I want them. I still see trees and greenery out my window (two windows, actually), thank goodness, and there are wild turkeys at the new place, too.

In the process, I finally got around to having my William Phillips “Clipper at the Gate” limited print framed at this little shop, and it came out pretty spiffy, with the frame and matting matched to the bluish silver of the aircraft, the deep blue of the water, and the red of the Golden Gate Bridge (actually called International orange) and the wing stripes. The aircraft is the Boeing B-314 flying boat, in this case the Pan American Airways California Clipper, NC-18602, which made regular runs between San Francisco and Hawaii – a nineteen-hour leg – before continuing to farther destinations.

Only twelve B-314s were produced by Boeing, all for Pan Am, but it was – and still is – considered the acme of flying boat technology. The initial six had a range of 3,500 miles with fuel capacity of 4,200 gallons and the second group of six could travel 5,200 miles with 5,400 gallons, both variants far exceeding the range of other aircraft of the day. Travel on the clippers was strictly deluxe, with ticket prices comparable to Concorde’s and meals catered by top-notch hotels.

The B-314 model on my desk, in the same 1:200 scale as the B-17 and B-747, is also of NC-18602. The “Fly to South Sea Isles” poster is a high quality limited edition reproduction of a 1930s Pan Am poster that was made about twenty years ago [some weeks after writing this, I found my Hansa Editions print was actually produced thirty years ago]. An original copy of the 1938 George Lawler poster – not the original painting, just a poster – recently sold for US$20,000 at auction, where the listing read:

One of the most iconic and desirable of all the early Pan Am flying boat posters, this image of the Boeing 314 Flying Clipper landing in a tropical lagoon captured, and continues to capture, the imagination of travelers. The location shown on the poster is an imaginary composite of several renowned bays throughout the South Pacific. It has been speculated that the view is Tahiti, Pago Pago and/or Diamond Head, however, the physical characteristics depicted do not coincide with the actual geography of any of these islands. Lawler most likely worked from photographs to derive a fantasy collage of a location infused with realistic details from various islands. It is rare to find this poster with text. We have found only two other examples at auction.

The tail end of the gallery shows in detail some of the photos and items on display. I had 16×20 prints made of the three high resolution Apollo photographs – done beautifully by Shutterfly and Snapfish, I’ll add. Of the three drawings of mine on the wall, just one, the woman holding a newborn Bengal kitten, is my original pencil drawing – the other two are from high resolution scans I made before presenting the original drawings to their subjects.

Click on any image to enter the gallery, and from there you can view a 1920-wide version of any photo by clicking this at the lower right (you may need to scroll down to see it):

 

Cease!

If every damn full moon is a supermoon, then there are no supermoons. Therefore, shut up.

super-duper-moon

Don’t be a luddy-duddy! Don’t be a mooncalf! Don’t be a jabbernowl! You’re not those, are you?

W.C. Fields in “The Bank Dick” (1940)

I don’t see the black moon arising

We have at last attained peak moon phase naming:

Rare Black Moon to rise on Friday in night sky of Western Hemisphere

So, it’s a second new moon, happens once every couple-three years, and you can’t see it. Not unusual, not rare, not visible. Got it.

“Rare” used to describe something common like this is related to the fact that teasing, please-click-me headlines that ask a question can nearly always be answered “No” and “arguably” in a news story almost always means “It’s not true that…”

My sincere apologies to Creedence Clearwater Revival for associating them with this.

The moon

If the moon is mesmerising to me on an everyday basis, like this evening when I paused to take this photograph, how transfixing must it have been for the last forty-five years to the men who once walked on it?

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