Study About Putting the Hexagon camera system on the Shuttle
In late 1963 it was announced that the Air Force had come up with a mission to conduct scientific experiments with astronauts in a manned orbital vehicle. The actual classified goal, to be run by the NRO (National Reconnaissance Office), was for the crew to perform photographic surveillance from the satellite of military assets in the Soviet Union and other adversaries. This became known as the MOL program. The satellite was to have been launched by the Titan III rocket.
The Air Force thought the MOL could more rapidly obtain imagery during crises than unmanned systems and much better resolution. The Air Force would develop the satellite vehicle while the NRO would develop the camera system.
After initial studies it appeared that the program was ready to be developed into a viable flyable system. However by that time in the mid sixties other reconnaissance satellite systems were being developed that had significantly better resolution and an expanded earth area coverage. In mid 1969 President Nixon cancelled the MOL program.
One major reason for the cancellation was that the Hexagon spy satellite design was in an advanced state of development and its testing showed promising results. The results showed imagery resolution was in the two to three foot region with the capability of taking stereo photos and mapping capability to photograph the entire landmass of the earth.
The first launch of a Hexagon satellite was on June 15, 1971. The Hexagon satellite became a successful and important tool for United States photographic intelligence gathering.
In the late 1970’s (1977 & 1978) a few of us at Perkin-Elmer who had worked on Hexagon from the beginning and one astronaut (I forgot his name) participated in a highly classified study to see if it was feasible to put a Hexagon mid-section on a shuttle-compatible pallet with a modified film supply using existing take-up reels as supply and take-up assemblies.
The Hexagon satellite consisted of a forward section containing four reentry vehicles, a mid-section that contained the two-camera assembly and an aft section that contained the film and electronics.
The whole satellite was launched on a Titan IIID rocket from Vandenberg AFB. When all of the film was used up the entire satellite was de-orbited and burned up and destroyed during reentry through the atmosphere and its particles falling in the ocean.
Using the shuttle to launch the redesigned mid-section would allow the camera system to be returned to earth for refurbishment and re-supply its expendable parts such as film, fuel and pressurized gas then return to orbit.
It would require the design of a pallet that would interface on one side with the mid-section and on the other side with the shuttle.
The study was done in a special “need to know” vault type area at Perkin-Elmer in Danbury, Connecticut. This was a highly restricted secured area and only several upper management staff even knew about the study. The reason that the study was highly classified was because it involved the shuttle and having a manned reconnaissance platform in space was a big deal compared to an unmanned platform. So the government agencies involved did not want anybody to know about that. This issue is not classified anymore.
My primary task was to come up with a conceptual design for the pallet.
The pallet would have to be a stiff and strong aluminum open truss and box beam structure that had the required stiffness and strength necessary to support the severe launch loads.
In order to protect the two-camera assembly from being subjected to excessive loads during launch it would be necessary for the pallet structural design to keep dynamic (vibration) responses of the two-camera assembly similar to the existing responses when Hexagon was launched on the Titan IIID rocket.
Our study concluded that a pallet could be designed to meet all of the load and vibration requirements and easily fit in the shuttle.
Naturally if the concept of putting the mid-section on the shuttle was approved another major study would have to be undertaken to redesign the film take-up and supply assemblies to interface with the two-camera assembly.
It turned out that the government never decided to fly the mid-section portions of Hexagon on the shuttle. I could not find any reason for this decision.
It also became known that the Rockwell Corporation had designed the shuttle bay to accommodate the entire Hexagon vehicle. That study showed that the Hexagon satellite would fit into the shuttle but by a very narrow margin lengthwise. The shuttle bay was 60 feet long and approximately 20 feet high. The Hexagon vehicle was only two or three inches shorter than the bay length and 10 feet in diameter so it could just fit in the bay lengthwise and not a problem for its height.
The preliminary drawing below shows an artistic concept of the entire Hexagon vehicle positioned in the shuttle bay. In order to launch Hexagon in the shuttle, the film capsules would have to face down, toward the payload bay floor. Giuseppe De Chiara drew this artistic concept.
It also turned out that the idea of putting the entire Hexagon vehicle on the shuttle was also never implemented and no reason was disclosed.
Since Hexagon mission 20 exploded above the pad at Vandenberg AFB in April of 1986 the launch of mission 19 on June 25, 1984 that lasted for 115 days was the last successful Hexagon mission.
The Hexagon program was succeeded by new orbiting digital camera systems. Their great advantage was that photographic imagery from space could be transmitted almost immediately back to earth to be analyzed.
It is sad to me that the use of the shuttle to extend the mission life of the Hexagon program was never implemented, as it would have further provided important intelligence imagery. Nevertheless I am proud to say that Hexagon was a major asset for United States intelligence.