AIAA Member Spotlight – July–August 2016 Written 1 August 2016

AIAA Profiles Phil Pressel

By Duane Hyland, AIAA Communications (2008–2017)
1 August 2016

Phil-PresselDeciding it would stay in the west, and wanting to experience a pleasant seashore atmosphere, the spotlight turned its beam from New Mexico to fall on San Diego, California, this month, illuminating AIAA Senior Member Phil Pressel, a semi-retired engineer, author, and Holocaust survivor. 

Pressel was a Project Engineer on the team that developed the Hexagon KH-9 satellite system for the Central Intelligence Agency while employed at the Perkin-Elmer Corporation, Danbury, Connecticut, which is now part of United Technologies Corporation. The satellite, only declassified in 2011, was the nation’s chief spy satellite until 1986 and played key roles in Cold War initiatives such as verifying Soviet compliance with the SALT Accords, as well as gathering intelligence on the movements and capabilities of the Soviet army and other strategic forces. The satellite system was such a closely guarded secret that Pressel reports that they presented the project’s initial study “to the CIA at night, in a deserted-looking safe house in Washington, DC, in 1966.” 

The first of the Hexagon KH-9 satellites was launched on June 15, 1971. There were a total of 19 successful launches over a span of 15 years. The 20th and last launch sadly exploded 800 feet above the pad at Vandenberg Air Force Base on April 18, 1986, just a few months after the Space Shuttle Challenger’s tragic explosion. Due to the classified nature of the program, Pressel could not discuss it with his family, who remained in the dark about what he actually did for a living until 2011, when the government declassified the project, giving him a chance to have those long-delayed conversations.

Pressel explained that he was responsible for the design of the KH-9’s stereo cameras, capable of photographing “every square foot of the Earth’s landmass, of course concentrating on enemy territory, to obtain strategic military information and economic information such as the condition of their agriculture.” He reminisced, “Even though we could not talk about what we were doing, I was incredibly proud of our achievements, as were all of the great team members who worked on it. We all felt we were doing very valuable work and got used to working in the ‘black,’ in a building with no windows, keeping documents in safes, using special phones, only discussing things with each other on a ‘need-to-know basis’ and occasionally traveling and identifying ourselves as ‘self,’ not representing our company or agency.”

In an interesting note, the Hexagon KH-9 satellite was the last U.S. satellite to use regular photographic film to capture its images. Pressel explained, “Each satellite contained four re-entry vehicles into which the film was stored after photography. As each bucket (re-entry vehicle) filled up it dropped back to Earth and an Air Force C-130 plane caught the bucket’s parachute as it deployed after it re-entered the atmosphere. Out of 19 missions and 76 re-entry vehicles, only one re-entry vehicle was lost, when its parachute failed to open and it sank deep in the Pacific Ocean. 

The CIA asked the Navy and Perkin-Elmer to conduct a highly secret operation to recover the sunk bucket because they thought there was a chance that there might still be some valuable photographic information on parts of the film. The Navy used the deep submersible ship Trieste to retrieve the vehicle using a Perkin-Elmer-designed large “claw” to grab and raise the vehicle. Unfortunately, the film was so severely damaged that no data could be recovered. 

Pressel wrote about his experiences with the KH-9 satellite program, how it was developed, how it actually worked, how secrecy was maintained, and many stories of the talented people who worked on it in his book: “Meeting the Challenge: The Hexagon KH-9 Reconnaissance Satellite,” published by AIAA in 2013. The book is available for purchase at

Long before he was secretly helping to keep the peace during the Cold War, he was born in Belgium. Because he was Jewish he and his parents fled to France in 1940 when the Nazis invaded Belgium. They avoided being victims of the Holocaust by hiding in French cities such as Marseille, Lyon, and Paris. In 1944 because of the severe bombings in Lyon all children had to be evacuated to the countryside. He was sheltered by a kind Catholic family in a small village near Lyon. Constantly homesick for his parents he was subjected to many hardships and more dangerous situations because the village was one of the headquarters of the French underground. 

Pressel added, “Fortunately, we three survived (and were reunited) and came to the U.S. after the war.” Pressel wrote about his experiences during the Holocaust in his book, “They Are Still Alive.” Over 25,000 Belgian Jews perished in the Holocaust, making Pressel’s story a unique one of survival and triumph against long odds.

When I asked Pressel about how he became a member of the aerospace community, he replied, “My education was as a mechanical engineer. I was fortunate when Perkin-Elmer Corporation (now UTC) in Danbury, Connecticut, hired me in 1965. This was a company that designed and built optical instruments such as cameras and telescopes, mostly for the government. I was immediately involved in studies for the CIA that would eventually become the Hexagon KH-9 spy satellite. He continued, “I learned a lot about the design and analysis of mounting optical elements such as mirrors and lenses and how to keep them in alignment and focus after being subjected to rocket launch loads, and when exposed to temperature changes.” Pressel also learned a lot about “designing space-qualified instruments.”

When asked if he had a mentor who provided guidance and inspiration to him during his career, Pressel replied, “One of my main mentors was Paul Yoder, an expert optical engineer who wrote several books that are now optical industry standard education tools.”

When it came to his favorite career memory, it is not surprising to find out that it stemmed from his work on the KH-9, as Pressel explained, “I attended the declassification ceremony for the Hexagon program 25 years after the program ended in 1986. Finally I could talk about my work to family and friends.” Of course, he continued, “declassification also allowed me to finish my book and have it published.” 

For students considering a career in aerospace, Pressel had a few pieces of advice. First, he emphasized: “Learn your science, technology, engineering and math – now known as STEM – well.” He noted that “is especially true in math,” and urged students to “develop curiosity in learning about how things work.” Pressel added, “In whatever task or project you are involved in ‘pay attention to detail.’ Obviously, learn to be competent with computers, and, depending on your involvement, learn about materials. This means learning about material properties, what is good or bad about them for use in the space environment – for example, do they outgas, meaning do they let off particles that can impede performance of critical parts such as optics and bearings?” Pressel also said that “senior members of the technical community should share their knowledge with students or junior engineers and present technical information at whatever meetings, conferences, or discussions they are willing to attend.”

We closed our talk with a discussion of the value of AIAA, with Pressel noting, “The value of AIAA to scientists, engineers, the public, and especially to students and those who plan to be involved in technology is immense. It exposes the challenges, the incredible instruments and methods of evaluation and analysis that have been developed and what challenges and opportunities there are to achieve in the future.

AIAA congratulates Phil Pressel for his selection as the July/August 2016 Spotlight subject, and wishes him the best of luck as he continues to educate the public on his speaking tours about the valuable role that the Hexagon KH-9 satellite played in preserving our nation’s security and freedoms.