The Great Pickett Slide Rule Apollo Conundrum

Long after shirt pocket sized electronic calculators and glass cockpits became the norm for both professional and recreational aviators, Colonel J. Michael Gibson, a career pilot and navigator with the Canadian Civil Aeronautics Search and Rescue (now retired) carried a Pickett N600-ES slide rule in his flight jacket. Its diminutive size (only 5" long), sharply marked scales, and sturdy construction made it a favorite for on-the-go users. A special purpose Pickett N700-T USAF Aerial Photo slide rule lived in his flight suit sleeve pocket.

Picket 1010 slide rule (sliderulemuseum.com) - RF Cafe

Colonel Gibson is passing along his appreciation for the art of slide rule usage to his granddaughter. She routinely uses her Pickett 1010 model to calculate everything from volume and weight of water in her grandpa's swimming pool to the percentage of laps completed in a NASCAR race.

Captain Robert L. "Hoot" Gibson (NASA photo) - RF Cafe

I know what you're probably thinking; I had the same question. The answer is no, as far as he aware, our Colonel Gibson is not related to Captain Robert L. "Hoot" Gibson of NASA's Space Shuttle fame - although the two have met at the Reno Air Races. Speaking of air races, Captain Gibson, who piloted STS-41B (c1984) and commanded other flights, was suspended by NASA from flight duties for a year in 1990 due to a risky activities rules violation at an air show in which he participated (see NY Times article). He resumed Shuttle missions after the suspension.

Part of Colonel Gibson's passion for all things slide rules is collecting and researching the models he has used over the years. In particular, he has focused lately on the Pickett N600-ES and its history aboard Apollo manned spaceflight missions. During one search session, he happened upon my Slide Rules page on RF Cafe where I have a couple photos of my personal N600-ES. The resulting highly informative e-mail I received from Colonel Gibson on April 22 of this year began an extensive series of reporting his ongoing communications with personnel from the Smithsonian National Air & Space Museum, Smithsonian National Museum of American History, Chroma (who bought Chartpak, who bought Pickett) and others regarding which types of slide rules were aboard each Apollo mission.

Pickett N600-ES "5 Moon Flights" box - RF Cafe

Motivating the extraordinary effort regarding the N600-ES is a marketing campaign on the packaging used by Pickett that proclaimed their company was "The Rule Used Aboard 5 Apollo Missions." Such a claim would not be suspect if it had not first appeared around 1968, a time when only Apollo 7, the first of the Apollo series to carry humans into space, had flown (but just into Earth orbit, on October 11, 1968). It was a "moon mission" only in the sense that it was in preparation for Apollo 8 - the first manned moon mission, which entered lunar orbit on Christmas eve of that same year. Pickett, it seems, had engaged in a bit of extrapolation about the potential number of moon missions whereon their products might fly rather than, as the display case implied, had already occurred. Even so, certainly there had not been five manned moon missions by that time.

Maybe Pickett meant that their slide rules were used during the planning of five moon missions?

Apollo 11 Slide Rule Auction Sale - RF Cafe

A "confirmed" instance of a Pickett N600-ES slide rule being aboard the Apollo 11 moon flight was the one auctioned off for $77,000 by Heritage Auctions in 2007. The accompanying letter of attestation signed by Colonel Buzz Aldrin (ret.) states in part, "Buzz Aldrin's Apollo 11 Slide Rule - Flown to the Moon. A Pickett Model N600-ES (Eye Saver) Log Log Speed Rule, a six-inch pocket rule with 22 five-inch scales. ... The rule offered here was flown to the moon aboard Apollo 11 by Dr. Aldrin." In evidence of the previous paragraph it also says, "The Pickett Company, founded in 1943, was proud of the fact that NASA selected this slide rule model of theirs to fly on five of the Apollo missions; they used that fact in their advertising of the period." Fine, except the claim was, as mentioned previously, reportedly made as early as 1968.

Colonel Gibson has dug deep into the history pertaining to which slide rules were carried aboard the Apollo missions, including long telephone conversations with museum staff, pouring over flight stowage lists, and interviewing actual crew members and/or their representatives. If you saw the complete contents of his e-mails to me, you could easily conclude that Colonel Gibson is collectively the world's foremost authority on this series of Pickett slide rules, on the Smithsonian Institution's archive of Apollo mission carry-on equipment lists, and on the history of the Pickett Company. He can even estimate the vintage of a Pickett slide rule based on the logo style.

I think his findings are deserving of a book, and maybe someday one will be in print, but for now, we can all express great appreciation for his efforts to uncover some of the forgotten treasures of the manned space program. For now at least, he offers this condensed accounting of his findings:

Which Slide Rule Really Went Aboard Apollo?...

By Col. J. Michael Gibson, Canadian Coast Guard (ret)

While researching the history of a Hemmi student rule for a friend, I noticed several references to the Pickett N600-ES rule being taken aboard Apollo.

Since I've met a few of the Gemini / Apollo and STS astronauts over the years, I asked around, and it turns out that some cannot recall even taking a slide rule aboard, yet I continue to see claims that a Pickett N600-ES went to the moon five times.

I found it interesting that out of seven attempts, and six landings ... two missions elected not to take the 600.

But which ones?

The Smithsonian website shows a slide rule that was aboard A13, and also says that this item is "not currently on display ... it is either on loan, or in storage", so I called them to find out where it might be. After speaking at length with one of the staff, we also discovered a letter from Captain Lovell and Ken Mattingly, marked - record incomplete - and the photo with it shows a Pickett N600-ES rule with a style 4 logo, fitted with the convex cursor.

This strongly suggests the rule aboard A13 to be an early version of a Pickett N600-ES.

Yet I've also been told that the one that NASA actually used had a magnified cursor, and I've seen photos that also support this claim.

To be a pocket sized rule from Pickett, and have a magnified cursor it must be either the Pickett 600 M-T, or the M-ES.

The convex cursor puts the slide rule somewhere between 1962 -> 1975, when they began using this injection molded cursor instead of the flat cursor they used earlier. So the year is correct - however - the magnified cursor that Pickett used on two of their model 600's, produces nearly full resolution detail on a pocket size rule. This cursor was normally only seen on the full size N3 and N4 rules, but no serial number is listed for this cursor. Pickett stopped using serial numbers on the cursor bars when they changed from magnesium bars to nylon.

Admittedly, this magnified advantage would be quite convenient if you are attempting to save both space, and weight, and you really wanted the most accurate results.

The staff I've spoken with at both the Kennedy Space Center, and the curators at the Boeing Field Museum of Flight by Seattle, were unable to yield any further insight.

Just to provide you, however, with some additional context, I located a request Christopher C. Kraft Jr. made for 33 slide rules required for "Flight Crew-Ground Controller procedural utilization" during Mission AS-204.

I emailed one of the A7 crewmembers, and found that they had a circular slide rule with them, that they used for orbital calculations, yet there was no mention of a Pickett 600 being aboard.

I also emailed a crewmember aboard A12, and he does not recall taking a slide rule along.

I did locate a couple of photos of Dr. Buzz Aldrin with a slide rule, and they do appear to be Pickett slide rules. Photo numbered S66-62984 clearly shows a rule with stamped aluminum contoured posts, floating by Dr. Aldrin, and that would date the rule to the latter half of 1959 at the earliest, which would be in the correct date range. But it's aboard Gemini XII, not Apollo.

I spoke with a few of the historians at NASA, and together with some very helpful staff at the University of Houston-Clear Lake, we have reviewed nearly 2,100 pages of stowage lists for Apollo, and found that things were pretty ad-hoc, right up to A15. The crews could take items along in their personal kits and NASA really didn't pay too much attention. They were even able to keep some of the camera lenses they had used if they wanted.

A10's stowage list shows the slide rule as a "deleted item", and the reason listed was "crew preference", but there was one (1) aboard. A11, there is also one (1) slide rule listed, and the location simply states "on crew". A14 also lists one (1) aboard, also "on crew", and in each case, NASA lists them all as part number SEB33100047-302, but no style, model or company name.

Interesting that the stowage lists mention how many pens a crewmember has with him, yet no mention of who has the slide rule...

NASA stickers on the slide rule boxes also began appearing which claimed first 3, then 5 Moon missions. So it would seem that NASA missions really did use Pickett rules. The subtle inference was that whatever rule you were buying was the one, when in fact it was not.

The packaging also changed during this frenzy and the 600's began appearing with the Lunar Module emblazoned on the outside and inside cover of the box. The style 6 logo on these "Apollo rules" is the real stumbling block here, especially when compared to the rule sold by an auction house that stated it was the 'actual rule' that was aboard A11, and the Smithsonian photos showing the rule that was aboard A13.

Neither had the style 6 logo.

Since the NASA stickers were appearing on everything from $0.50 plastic pocket rules to the high end ones, there's no real clue there. And we know that Pickett really pushed the 6" pocket rule as a unique product to them.

The rule the auction house sold for $77,675.00 on September 21, 2007, was accompanied by a letter from Dr. Aldrin attesting to it's authenticity. That rule has;

- stamped aluminum posts, with a symmetrical contour

- nylon cursor bars - a grooved convex lens

- the photo also shows a grooved slide

- it bears a Style 5 logo (which was used by Pickett from 1962 -> 1964)

- the convex lens shown in the photo was used from 1960 -> 1975

This rule would be at least five years old by the time it went along with Dr. Aldrin, and is from his "personal collection" -- according to the letter that accompanied it. The one aboard A13 was even older, as the style 4 logo was used from 1958 -> 1962.

Now we have two cursors, and a style 4, 5 and 6 logo to choose from.

I located some photos of the labels Pickett glued to the end of their packing boxes that were emblazoned with the Lunar Module, trumpeting the claim that they were aboard 5 Moon missions, and 5 Apollo missions. The problem here is, they also made this claim on a 1968 product catalog - and the first Lunar mission was not until December of '68.

You would expect a new product catalog to be disseminated in January. Not December.

They also packaged four different types of rules in these boxes, and suddenly claimed the rule had 22 scales, instead of 19, yet no new scales were added - they just counted them differently. If you count the LL scales as one, you get 19. However, the LL scales are actually LL- and LL+, which of course, would be two. Count them that way, and the same rule suddenly has 22 scales instead of 19.

Pickett is busy packaging these rules with their style 6 logo, and gluing labels to the boxes on all but the 600-ES versions, claiming this was the one that was carried aboard 5 Apollo missions, yet both the 600 M - ES, and the 600-ES versions were being sold in these boxes, and the Apollo program is winding down.

Apollo 16 is launching on April 16, 1972.

The retail price of the ES version was about $10.95, and the M - ES was about $5.00 more, and sometimes slide rules were mislabelled. Or even misrepresented by the number of scales it had.

Pickett Industries now moves to Nogales Mexico in 1974….

Chartpak Inc, the company that Pickett Industries was sold to in 1985, have not carried slide rules in years, and subsequently sold to Chroma in NY, and as it turns out, Chroma disbanded their drafting department around 2014 / 15, so there are no records there either.

So which slide rule really went aboard Apollo?

It seems likely there were three (3), and NASA, in its typical fashion, by not recording the specific type that was used, prevented any one company from getting all the attention. After all, if you've used one of these instruments, you probably have your favorite, and if your life is depending on the result - having an old, trusted friend with you would be a nice feeling.

Shown here (left) is my Pickett N600 M - ES, and you can clearly see how much magnification this style of cursor provided.

My other Pickett N600 ES (right) is equipped with the standard cursor, and is only slightly convex.

If you look closely at both of these photos, you can see the LL- and LL+ scales, the style 6 logo, and the cursor bars with hooked, as well as symmetrical curves. All significant details needed to date the rule. Both of these rules could easily have been the same as the ones carried aboard Apollo.

This final update reports on a note from the Curator, division of Space History at the Smithsonian Institution about their Apollo 13 Slide: "After speaking at length with one of the staff, we also discovered a letter from Captain Lovell and Rear Admiral Mattingly, marked - record incomplete - and the photo with it shows a Pickett N600-ES rule with a style 4 logo, fitted with the convex cursor. I followed this up with the Curator, Division of Space History, who had called both Captain Lovell, and Rear Admiral Mattingly - only to discover that both have no recollection of this slide rule."

Colonel J. Michael Gibson served in the Canadian Navy as a Marine Engineer, then went into flight school and onto Advanced Air Combat Maneuvering training flying jet transition light attack aircraft. During that time he picked up a Masters in Computer Science, and also a minor in Industrial Electronics and Robotics. Since retirement, he picked up a second language (Spanish), a Level 1 Certification in Infra Red Thermography, and a Home Inspector certification, and a Power Engineering license. Colonel Gibson's flying activity includes having flown DC3s, SNJs, P51TFs, SF260 Marchettis, Cessna 172s, Piper Cherokee 140s and 161s, while accumulating over 800 hours Pilot-in-Command time.

All I can say, to quote a contemporary U.S. political figure, is "Amazing!" The world could use a lot more people like Colonel Gibson.