Kodak’s “Pre-Invented” Lunar Orbiter Camera; or, The Fate of SAMOS Readout

Left: The Lunar Orbiter camera system sitting in the bottom half of the pressurized shell. Project Manager Cliff Nelson (left) stands with NASA/Langley team members Calvin Broome, Israel Taback, and Joe Mooreman. From NASA. Right: Lunar Orbiter frame 5017-M, showing artifacts from Kodak’s camera system. From NASA/LOIRP. In 1966 and 1967, NASA sent five robotic spacecraft into orbit around the Moon. Constructed for the primary purpose of finding landing sites for Apollo, the Lunar Orbiters also enabled nearly comprehensive mapping of the Moon in stunning detail. The quantity and resolution of the photographs returned by Lunar Orbiter was unprecedented, thanks to a camera system built by the Eastman Kodak company of Rochester, New York. Their imaging system involved elaborate mechanisms to expose photographic film in orbit, develop the film onboard the spacecraft, and remotely transmit images back to Earth. In February of 1967, the Rochester Times-Union published a story about how Kodak had “pre-invented” the Lunar Orbiter camera. Kodak director of R&D Arthur Simmons told the Times-Union that “no one walked in and asked us to develop a camera and film system to take closeup photos of the moon…Kodak has, for want of a better word, a ‘library,’ of hundreds of ‘conceptual ideas’ which we don’t advertise.”1 But the story of the camera’s “pre-invention” was more interesting than Simmons let on. When Kodak joined Boeing’s bid for the Lunar Orbiter in 1963, the camera system already existed. The company had originally developed it for the Air Force in the 1950s as a part of the highly classified satellite surveillance program called Weapons System 117L (WS-117L). The nature of WS-117L and the clandestine origins of the Lunar Orbiter camera system were vaguely known by some at the time, but the full details were only revealed to the public through declassification decades later. This article won’t linger on the detailed technical specifications of the Lunar Orbiter cameras, but will instead focus on tracing the system’s development from conception to its adoption by NASA. It is the story of some of the first attempts by the United States to remotely transmit images from space, and how those same systems were adapted for lunar exploration. WS-117L had roots in RAND studies of satellite surveillance concepts going back to 1946, and was the first major attempt to put those ideas into practice. The United States was hoping that satellites could be used to monitor the buildup of nuclear weapons and launch sites in the Soviet Union. In 1953, RAND Report 262 laid out in full the feasibility and utility of such systems, and by 1955 the Air Force began soliciting contractors for WS-117L. Eastman Kodak created camera systems for Lockheed’s bid, and the the Air Force awarded their contract in October of 1956.2 Timeline of the Advanced Reconnaissance System, or WS-117L, from a 1958 summary. From NRO (PDF). Originally, RAND had primarily considered using television systems.3 “Near real time” imaging was considered by some to be the ideal form of satellite surveillance, so television was a logical choice. But in a declassified history of the program, Robert Perry explains that the goal of real time imaging quickly became contested within the Air Force–it was unclear whether the technology was ready to satisfy requirements, and the alternative film recovery systems showed clear feasibility and reliability early on. Some of these efforts were spun off from WS-117L into the Discoverer-CORONA program, which sent Kodak camera systems into orbit, and returned capsules of exposed film for aerial retrieval and processing back on Earth.4 Early on, however, a near real time system was very much a part of the plan. In their bid for WS-117L, Kodak created a remote transmission system that would fly in what became known as the SAMOS program. Television systems were still in consideration early on, but there were clear technological limitations at the time, especially when it came to resolution. Kodak’s newly formed Apparatus and Optical Division settled on a system to develop film onboard the spacecraft and “readout” the images to receiving stations on Earth. Planners envisaged five cameras for SAMOS, the first three dedicated to testing Kodak’s readout system (the others testing advanced recovery stems). The E-1 camera would primarily be a technology demonstrator, while the E-2 and E-3 would test the ability for their system to take images at more functional resolutions. All used the same basic architecture. A diagram showing the various SAMOS camera systems and their proposed capabilities. From NRO (PDF). In a way, this camera system was in fact “pre-invented,” as it was mostly a clever assembly of existing technologies, many created by Kodak. The company had decades of experience in aerial photography going back to World War I. By the end of World War II, they had created advanced aerial films, compact film storage systems, and image motion compensation techniques. They had also worked on IR bomb sights and proximity sensing for the Navy, which would become useful for developing thermal control materials for the spacecraft.5 Illustrations from 1957 show a rough sketch of their plans for SAMOS readout. Kodak’s 70mm film would be exposed, processed, and stored before readout and transmission. Electronic signals received on the ground would be used to reconstruct the images. An early diagram showing the SAMOS readout system without some of the key details. From NRO (PDF). By 1958, planning documents started detailing two of the key technologies that ultimately made the readout system possible. One was what became known as Kodak “Bimat” film, labeled in the illustration below as “WEB.”6 This web was coated with gelatin containing the necessary processing chemicals, enabling “dry” processing. The web was pressed against the exposed film, developing and fixing the images before storage and transmission.7 Diagram from a 1959 Lockheed briefing on the SAMOS program, image is labeled September 1958. From NRO (PDF). The origins of Bimat film are somewhat obscure in the public record. One Kodak-produced history suggests that the technology started as a laboratory investigation with amateur photography in mind, and was then applied to use in aerial photography.8 Considering the timeline, it was either a happy accident that this experiment matured just in time for WS-117L, or Kodak engineers started looking into the technique specifically in response to the challenges of film photography in space. A Lockheed development plan from March 1956 describes the processing system in vague terms, stating that it would “not differ significantly” from existing methodologies for “airborne rapid-processing,” and describing a notional “a roller-applicator type” system. It also lists “the handling of photographic chemicals” as one of the “major difficulties to be overcome.”9 The illustration from 1957 shows the onboard processing step without the “WEB,” a detail that only shows up in diagrams like the one above labeled 1958.10 Then, a patent for a “web processing method” was filed in August 1959 by Kodak researchers, presenting “a one-step method for substantially completely developing and fixing a photographic image…without immersion in photographic processing baths.”11 David McDowell, an engineer who joined up with Kodak in late 1956 and worked on both SAMOS and Lunar Orbiter, also remembers Bimat being developed specifically for the project. “Bimat was started as soon as we started work on E-1 and E-2,” he told me, “because we knew we had to process film in orbit.”12 The second key technology was the readout system itself, which involved collaboration with the Columbia Broadcasting System Laboratories to create a flying-spot scanner.13 It worked using what McDowell calls an “inside-out CRT,” using a cathode-ray tube that fired an electron beam through the exposed film. Variations in the density of the film changed the intensity of the beam, and those variations were recorded by a photomultiplier and translated into electronic signals that could be sent back to Earth. Teams on the ground received those signals, used equipment to translate them back into an image, and recorded that image on film. Before passing through the film, the beam reflected off a revolving drum (seen in the diagram below) for thermal management. Diagram of the SAMOS readout system from the same Lockheed briefing. From NRO (PDF). In October 1960, the first E-1 camera launched on an Atlas-Agena, but failed to inject into orbit. Meanwhile, officials were actively debating the wisdom of continuing the readout program. Costs were rising, engineering difficulties plagued the program, some of the technology was beginning to seem obsolete, and CORONA-like systems were looking like a better option until more advanced readout techniques could be developed. Despite these issues, there were advocates for readout, and tests continued so that any decision could be made based on tangible results. In January 1961, the second SAMOS test launched with another E-1 camera and sailed into orbit. In Sunnyvale, California, technicians at a readout station received transmissions from the spacecraft, and the result was a photograph with a 100 foot resolution. The system had worked.14 The E-2 camera would be the next step, with more advanced aiming systems and a higher resolution. All of the rotating systems within the spacecraft created complexities when it came to achieving these objectives. One key difference between E-1 and E-2, McDowell recalls, was that E-2 used a rotating nosecone to help stabilize and aim the camera.15 A diagram of the payload section for E-2, showing the “steerable mounting” that made it distinct from E-1. From NRO (PDF). A diagram from SAMOS planning documents showing the proposed aiming and stereo operation capabilities of the E-2. From NRO (PDF).