About the Hexagon Rocket Explosion in 1986

Memories About the Hexagon Spy Satellite explosion

By Phil Pressel

I am writing this to further honor the program and provide some personal views previously not documented.

The explosion of a Titan rocket at Vandenberg Air Force Base on April 18, 1986 marked the end of the Hexagon Reconnaissance  Satellite program.

April 18, 2016 was the 30th anniversary of this significant event as it was the 20th and last film based reconnaissance satellite of the Hexagon program. The Hexagon KH-9 satellite was a highly successful “spy in the sky” orbiting satellite that provided important intelligence for the United States. The cameras and resulting photographs permitted President Nixon to sign the SALT Treaty and enable President Reagan to “Trust but Verify” what our cold war enemies were doing. 

I had worked on the system from the beginning of the program in 1965. On April 18, 1986 as I was coming out of a meeting I was met in the hall by the general manager of our division (Paul Petty) and he told me about the explosion. I immediately choked up and tears came to my eyes. I rushed to my office where, in solitude, I cried. So many of us had devoted many years to this project. It was like a family member dying. It would be the end of an era for all of us. It was the job of a lifetime and was so important for the US.

The explosion was only 3 months after the tragic Challenger explosion that killed 7 astronauts. Fortunately the Hexagon was unmanned and no one on the ground was hurt although there was quite a bit of damage. We had flown 19 successful missions starting in 1971. The development of this system, that was “the most complicated satellite ever put into orbit,” resulted in the development of many state-of-the-art technologies. When the program was declassified in 2011 it was revealed that it had a photo resolution of 2 feet from 100 miles up in space.

Our customer was the CIA. To everyone on the program they were referred to as “the customer” since most people on the program were never told who the customer was.

The “customer” guys (no women), as a matter of fact there were no Perkin-Elmer women engineers or drafting personnel on the job except for clerical and perhaps two lady scientists. This was in the sixties and early seventies and sad to say.

The customer had very capable engineers, scientists and managers. They were quite tough on us but the whole process was successful. We made many presentations to them mostly in the form of design and system reviews of every major subassembly on Hexagon. Participating in these reviews were their consultants from TRW, Aerospace Corporation, the Presidential Security Advisory Council headed by Edwin Land and several others companies.

The CIA staff we worked with were part of the CIA’s Directorate of Science and Technology that did tremendous scientific work that the public did not know about. They made some valuable suggestions and some criticism but most (other than two contentious guys) were great to work with. We as well as they,  wanted a successful program outcome more than anything. 

In the 1972 or 1973 timeframe, an unexpected event happened. We were told that the program had been transferred from the CIA to the Air Force. This was at the beginning of the contract for the second set of 6 Hexagon systems.

This was done because the program by then was operational and the launches were being run by the Air Force from Vandenberg AFB. This enabled the CIA to concentrate on newer projects. The transfer proceeded rapidly and with a minimum of problems.The one significant change after the transfer was the incorporation of a new star-tracking device called S-Cubed (Spaceborne Stellar Sensor). It was mounted on the camera’s support frame (there were two S-Cubed sensors on each mission). They looked at the sky through two apertures on opposite sides of the vehicle. The frame that supported these sensors was the one that supported the optical bars (cameras) and loopers and other critical assemblies. The star trackers observed stars as faint as ninth visual magnitude and defined Hexagon’s orientation. It was first used in the 1982 time frame on the 17th and subsequent Hexagon missions.


The following are portions of interviews that I conducted with some key participants in the Hexagon program. Most of them were my colleagues, engineers and managers at Perkin-Elmer. 

Frank Grabowski was an electrical technician on the program for many years. His tasks included wiring test equipment for most of the major subassemblies. One of his tasks was to help top-off the nitrogen tanks in our system while it was on the launching pad at Vandenberg.

Before Frank’s trip he told me he had asked our Security office if it was okay if he could videotape the launch from his motel in Pismo Beach about 3 miles from the launch site. The following was what he told me.

 “I attended a security indoctrination lecture at Vandenberg, and then was sent up to the 16th level of the gantry to help top-off the nitrogen tanks. I was speechless at first when facing the Titan 34D as it was so awesome. Before I descended I wished it ‘Godspeed.’

When I got back to the motel I purchased a bottle of champagne and some cups for a toast with my colleagues. There were launch delays, but finally at 10:44 a.m. Pacific time I started video taping outside the motel. Meanwhile my boss Jules Cohen, and other colleagues were in the blockhouse near the pad and in contact by a “red phone” with those at the motel.

As the launch started I yelled ‘Go, baby, go!’ Then I saw a purple-orange cloud of gas. I realized that there was an explosion. I was devastated. This became the worst day of my life. I threw the camera with the recording into the trunk of my car. I then threw the bottle of champagne into the brush.  Hours later Jules and some others who had been in the blockhouse were escorted away by Security after the cloud of gas had cleared. I went to my motel room and cried. I said to myself, ‘I don’t want to see the videotape.’ When Jules came back to the motel he insisted on playing it. I was very uncomfortable seeing big chunks coming away from the explosion. What do I do with the tape after I played it? I hid it under my bed.

I got a telephone call in the room from someone saying they were with Security and saying, ‘I understand you have a video tape of the explosion. Do you have any copies?’ I said no. The man said, ‘Tomorrow at 10:30 AM go to the hotel in Sunnyvale and bring the tape and I will meet you there.’ I became very nervous. I put the tape in a brown paper bag and met him as requested. I handed it over to the man and obtained a receipt for it. I still have the receipt. I left the hotel and got my car to go to the airport. I was nervous. I couldn’t open the door to the rental car. It was the wrong car. Sweating and sad I flew back to Danbury. It was a sad trip for me.

Several months later in Danbury I was called to the main conference room. They were showing the video. They wanted me there as the maker of the video. The video showed the explosion from a vantage point other than the films taken from the blockhouse. It turned out that watching the video again helped me to get over the trauma since for security reasons I was not allowed to talk about it at home.

To this day I relive the moment every April 18 at 1:45 PM Eastern time by stopping what I am doing and standing in silence.

Vic Abraham the general manager of the program at Perkin-Elmer  at that time said, “we were standing there waiting for the blast off. We were in the fallback position. It was 8 seconds into launch when it exploded and the wind blew towards us. I was standing there with other government people. This cloud of yellow smoke from the boosters was coming our way—we had to run like crazy into our cars and ‘get the hell out of there.’ I wanted to see the launch in person, not on camera in the blockhouse as I was for other launches. Then later we didn’t know what to do with ourselves. Our hearts went out.”

Frank Harrigan was the Manager of the Perkin-Elmer West Coast Field Office located in one of the Lockheed buildings in Sunnyvale, California. Lockheed (before it before it became Lockheed-Martin) was the prime contractor that assembled and tested the Hexagon vehicle’s major components. The systems that Lockheed assembled and tested included the camera/film handling system designed and built by Perkin-Elmer in Danbury, the film that was supplied by the Kodak company in Rochester, the re-entry vehicles that were supplied by the McDonnell–Douglas company in St. Louis, and electronic and support equipment supplied by   others. 

Frank told me “What a terrible thing. This is no way for us to end this successful program. Most importantly at that time the United States did not have any launch lifting capability for any vehicle this heavy. It was that serious. We lost the challenger and we lost the Titan. You ask if I was worried about my job and hell no, I was not worried about that at all. I worried about the guys in the blockhouse. Emotionally I felt terrible. We were told to stay a few days for some of our crew to go over the grounds to pick up debris and most importantly any film that might have been scattered over the grounds, because for security reasons that would have indicated that the payload was a spy camera and very few people at Vandenberg knew the contents of the payload.

George Manolis, a quality control engineer with Perkin-Elmer recalled “after the explosion security had concerns with the possibility that any leftover film could be spread out over a huge area at Vandenberg’s launch site. Evidence of film in the area would be a major security problem.  Ten of our team was assigned to go throughout the base with black plastic bags. We scoured the area for several days, and picked up all the pieces of film that survived the explosion we could find and turned the bags over to security. Only some of the film had unraveled from its reels. There had been a total of 60 miles of film on the satellite.”  

Dick Parker was the supervisor of electrical and mechanical technicians at Vandenberg Air Force Base. He worked for Lockheed-Martin at Vandenberg and for 30 years was involved in launches of all types of rockets. This is what he told me:

“For that launch I chose to see it from the fallback position approximately 3 miles from the launch pad. My office was in a trailer directly across from the control center. When that thing blew up my office was destroyed by pieces of the solid rocket propellant that hit the ground and just sliced right through columns of beams and reinforced concrete. All that was left was a pile of rubble and a big crater. It was the most horrendous site that you could ever imagine and very traumatic.

Overall there was $73 million worth of damage done to the entire site and it took months and months to recover from that. The investigation indicated that the liquid stage of the titan missile did not ignite until the burn of the solid rocket. The solid rocket motors are what got the thing off the ground. When the blast occurred it was the result of a burn through of the insulation and outer casing of one of the solid rocket motors that sent a bulk of molten material into the liquid propellant stages and exploded the two un-expended propellants of the core vehicle.

It created a great big orange cloud that slowly began to drift towards my location. An emergency evacuation announcement was made over the public address system and we evacuated the area and headed to the north. The craziness of the situation stuck out. There were numerous witnesses to the scene lined up on highway 135 and as we made the turn exiting the gate you saw the most chaotic scene imaginable as people were fearful of that cloud that was moving directly above them.

We attempted to enter the flow of traffic and right in that whole maze came a string of fire trucks going in the opposite direction. How those fire trucks got through that mess of cars was a mystery to everybody and that we were very fortunate that somebody didn’t get killed.

I very much felt in danger and very much concerned with the well-being of the 78 people ensconced in the blockhouse in the control center. We thought for sure all had lost their lives. So we were indeed fortunate not to lose a life.

It was 3 days later when we could return to the site and I only then realized what happened and that my entire office had been lost. I was devastated at the loss of many personal items I had in my office.

Martin Marietta had a recovery team there and one of their quality control people was an avid horse person and volunteered the use of some of his horses to clomp through the waist high mesquite and branches of the undercover all around the site to search for debris as it was rattlesnake infested. I don’t think any horses suffered from the snakes that were probably killed by the explosion. The riders found various things they had no knowledge of and turned it over to security. The local military was not cleared for the program and was not allowed there.

Finally Ken Dudschus, an engineer who monitored all vehicle data during testing and launch, said:

“I was in the basement of the blockhouse when I heard the   tremendous noise of the explosion. The whole blockhouse started rocking like crazy and I thought we were all going to die. We   received a phone call from Jimmy Dimas, one of our technicians located elsewhere at Vandenberg, to determine if we had survived.

There were armed guards in the blockhouse with us and they apparently had orders not to let anyone of us to leave. That included one woman who had an asthma attack. Another nearby building, one that contained all the air conditioning equipment for Lockheed and the blockhouse was destroyed, so we had no air conditioning.

Hours later, with the ‘all clear,’ we were eventually evacuated, boarded buses and brought to our motels. We were all thankful that we survived but we still could not tell anyone what the real purpose of the launch payload was. Now that the program has been declassified I can tell family and friends that it had been a top-secret spy satellite.”