The Story of Phillip N. Slater

My connection to Phillip Slater starts as most of my stories do, with me looking for awesome books to add to my collection. I was on eBay a Thursday afternoon in November 2024, browsing as I normally do. This time, I was looking for NASA-SP publications to add to my collection, I have several texts and collections from NASA, and I am a big nerd.

I browsed for a bit, and found a listing for vintage NASA books, 4 of them, 3 of which were NASA-SP publications. The price was fair, so I purchased them. Additionally, the description said these books were signed, which is always a treat and adds some history to the books. A week later, the books arrived at my door, and I unboxed them. However, I did not immediately look inside or catalog them, as I had to leave for conference in North Carolina the next morning, so I had to back and get to bed.

A couple weeks go by, and I am busy as always, and accidently place some papers on top of the books on my desk, which hid them from me for a further week or so, until I got the chance to clean up my desk. When I finally looked, 2 books caught my eye. These books were NASA SP-349, “Pioneer Odyssey”, and a small paperback titled “…for the benefit of all mankind”. Pictures of both are below:

Pioneer Odyssey, note the original NASA logo in the bottom left!

…for the benefit of all mankind, this one held some surprises.

In the cover of Pioneer Odyssey, there was inscription to Phil and a signature from one Charlie Blenman, who appears to have been a program manager on some aspect of the Pioneer program. Further in the book, another inscription to Phil and signature is from William Swindell, one of the authors of the book. Both inscriptions are dates to January 18th, 1978. Pictures of both inscriptions are below:

Charlie Blenman’s Inscription. Phil was the associate director of the Optical Sciences Center at the University of Arizona at the time, and appears to have helped quite alot with the pioneer 10 spacecraft.

William Swindell’s Inscription. William worked at the OSC with Phil, and they were likely colleagues.

We will get back to Phil’s career and accomplishments, of which there are many. However, a very interesting surprise was waiting on the cover of the paperback copy of “…for the benefit of all mankind”. When I opened the book to get catalog details, some papers fell out. This is not unusual for me, I find notes, old homework, etc. in books all the time, comes with the used book territory. However, I have never found something like this. What fell out of the book was 3 postcards from the Apollo 17 launch in 1972. Furthermore, one of the postcards was not just memorabilia, but was a handwritten card from Phil to his daughter, Elizabeth. Here are some pictures:

The 3 postcards. The large image is of the Apollo 17 mission’s Saturn 5 rocket, the small print card is a list of all Apollo 17 mission events, and the handwritten card will be featured up close next.

Phil’s postcard to his daughter, Elizabeth. He mentions that he met up with Elizabeths uncle and aunt from the British embassy (Phil is British by the way) and that they are all sitting on the grass 3.5 miles away from the launch pad 2 hours from launch in December 1972.

After finding these, I knew I had to investigate who Phil was, and why this was in my hands instead of a frame somewhere. Luckily, Phil was rather easy to find, as he was a distinguished faculty member and researcher at the University of Arizona in the Optical Sciences department. Sadly, the answer to why the books were in my hands was that Dr. Phillip N. Slater passed away on the evening of February 4th, 2022, at the age of 89.

The rest of this entry will be me recounting my research into Dr. Slater’s career, research, life, and legacy.

Dr. Phillip N. Slater was born in 1932 in the United Kingdom. He attended Imperial College and received his B.Sc. degree in 1955, then attended the Imperial College of Science of Technology in London for applied optics, completing his Ph. D in 1958

Photo of the Imperial College of Science and Technology, established in 1907.

Upon the completion of his education, Dr. Slater moved to the United States and began work as a research physicist at the IIT Research Institute in Chicago. He worked as a manager at IITRI from 1962 to 1966, and his work was focused on optics research. During this time, Dr. Slater became an expert in aerial and space photography, which led to his recruitment to the University of Arizona in 1966. Upon his arrival at the university, he began work as a research professor at the Steward Observatory

Photo of the Steward Observatory, named for Mrs. Lavinia Steward for her donation of $60,000 for a 36in diameter Newtonian telescope in 1916.

After 1 year of working at the observatory, Dr. Slater joined the growing Optical Sciences Center at the University of Arizona as a Professor of Optical Sciences. Dr. Slater was one of the first faculty hired by the brand new optical sciences center, and would be instrumental in its success. Dr. Slater served as the assistant director from 1968 to 1973, and the associate director of the Optical Sciences Center from 1973 to 1975. If we recall the inscription from Charlie Blenman, Dr. Slater supported the Pioneer Jupiter team during his time as the associate director of the OSC.

Photo of the Meinel Optical Sciences Building

Regarding Dr. Slater’s support of the Pioneer Jupiter Team, I looked through the book and found that NASA did us the solid of listing the program contributors and researchers in the back of the book, so I was able to find exactly what Dr. Slater and his colleagues worked on. The text credits the University of Arizona research group with creating the “Imaging Photopolarimetry Experiment”, the Principal Investigator of which was Dr. Tom Gehrels, and his team included Dr. William Swindell and Charles Blenman, the inscribers of Dr. Slaters book.

Photo of the Imaging Photopolarimetry Experiment instrument. “The instrument observed faint flows in interplanetary space of Zodiacal Light, the Gegenschein, and the integrated starlight. At Jupiter this instrument was used to look at the reflective properties of the Jovian atmosphere and of satellites to build up spin-scan images of these bodies” The Pioneer Odyssey, fig. 4-14.

The below images are from appendix 1 in the Pioneer Odyssey, ad describe the instrument in detail:

For those who are not aware, the Pioneer 10, AKA the Pioneer Jupiter was a NASA mission that was the first ever mission to go to the planet Jupiter. The probe launched in 1972 and carried multiple scientific instruments to gather data about our solar system.

Photo of the Pioneer 10 on just prior to launch in 1972

The Pioneer 10 spacecraft holds the additional distinction of being the first manmade object to leave the proximity of the major planets of the solar system and did so in 1983. The last telemetry we received from the Pioneer 10 was in 2003, when it was 7.5 billion miles from Earth. We have not heard from it since. Additionally, Pioneer 10 is famous for its plaque, as advocated for by Carl Sagan. This plaque symbolizes humanity reaching out into space hoping to find intelligent life.

Photo of the Pioneer Plaque, which has various information about humanity

Photo of Jupiter taken with Pioneer 10 instruments, the first-time humanity had ever seen the gas giant in such detail

The principal investigator of the UA team was Tom Gehrels, who has made some monumental contributions to the sciences in his own right, learn more about him here.

So, as we can see, Dr. Slater and his colleagues were titans of innovation, discovery, and exploration. Dr. Slater’s research interests included atmospheric effects on spectral signatures and the design and calibration of multispectral linear-array systems for remote sensing of the earth’s surface from space. In his career, he published ~90 research works, including his textbook, “Remote Sensing: Optics and Optical Systems”, published in 1980.

the following are some words from people who knew and worked with Phil:

“I knew Phil since 1984 and was proud to be among the diverse group of students and visiting scientists that he managed. Under his leadership we worked well together to advance government-sponsored work with calibration of space-based and aircraft remote sensing instruments. We spent many days (and nights) at interesting field sites such as White Sands missile range where the students and visitors camped in tents. I always remember our field work as interesting and fun, and Phil always did more than his share of the field work carrying back-pack mounted instruments! I’ll always remember him as a great example, and my advisor, mentor and friend.,” -Dr. Stu Biggar, Research Professor of Optical Sciences and a close colleague of Phil’s at OSC

“My remembrance of Phil was establishing a short course in optical sciences before they were in style. It was a 2-week event for industrial affiliates, as well as anyone else, to take 9 courses at two topics per day in 4-hour lectures. The social gathering and parties afterwards at night provided entertainment, but also possibilities to establish mutual research interests with industry. Phil was a pioneer in that effort along with his wife Joan.” -Eustace Dereniak, Emeritus Professor of Optical Sciences

“In his humble, but impactful way, Phil was an early and very important OSC faculty member. As associate director for several years and head of an excellent, well-funded remote sensing program, he did much to strengthen our program and reputation. Aside from work, one of his favorite activities was running, and he especially enjoyed talking some of us into joining him for a few miles at lunch time, all months of the year, including July! Some of my fondest memories are of the yearly OSC Saguaro East race that Phil was instrumental in starting. Not only did he participate in the race, but he and Joan also hosted an amazing breakfast for everyone at their house afterwards.” -Jim Wyant, Founding Dean and Emeritus Professor of Optical Sciences

“In memory of Phil I went to Saguaro National Park East today – I’m no longer able to run the 8.5 mile loop, so instead I did a 8.5-mile hike up and down Tanque Verde Ridge Trail. Perfect way to think about it all … Brought all kinds of wonderful memories from the old days…” -Pierre Meystre, Regents’ Professor Emeritus of Optical Sciences

As we can see, Dr. Phillip N. Slater was a pillar of his community, a devoted family man, and a scientific titan. Phil and his wife Joan where also sponsors of the Phillip N. and Joan A. Slater Scholarship each year.

And that is as much of the story of Dr. Phillip N. Slater that I could find publicly available. Most of my info come from here. I hope you got something out of the story, or at a minimum, learned something interesting!

-Ethan