Salter, Robert M
Born: 1920-04-20. Died: 2011-05-17.
Robert M. Salter, Jr. was a physicist who worked with the North American Aviation, 1946-1948; Rand Corp., 1948-1954; Lockheed Aircraft Co., 1954-1959; Quantatron, Inc., 1960-1962; and Xerad, Inc., since 1962. He was responsible for much of the early thinking at Rand on the possibility of an artificial Earth-orbiting satellite.
Obituary: Space Review: A father of national reconnaissance, Robert Salter, by Dwayne A. Day, Tuesday, July 5, 2011
Every year the National Reconnaissance Office (NRO) inducts people as Pioneers of National Reconnaissance. Robert Salter remains one of the people the NRO has overlooked. He died in May at the age of 91, and he was one of the first people to ever study in detail the possibility of placing a satellite in orbit to collect intelligence about what was happening far below.In 1946, Salter, Jack Lipp, and one other person at RAND served as the editors of the report “Preliminary Design of an Experimental World-Circling Spaceship,” the first report ever produced for the US government on the possibility of building and launching a satellite into Earth orbit.
Salter was born in Morgantown, West Virginia, on April 24, 1920. His father was an agricultural scientist and Salter graduated from Ohio State in 1941 with a bachelor’s degree in mechanical engineering. He first became interested in space after reading the Buck Rogers comic strip as a kid. He started working as an intern at General Motors Labs in 1940, which was then performing a lot of advanced research that had little to do with automobiles. During the war he served as a commissioned officer in the Navy, working in the Bureau of Aeronautics power plant design branch, which included work on ramjets and missiles.
When the war ended, he soon left to work for RAND, a division of Douglas Aircraft in Santa Monica, California. His interest in rockets led to his work on the satellite study that RAND was undertaking at the request of the Army Air Forces. In 1946, Salter, Jack Lipp, and one other person at RAND served as the editors of the report “Preliminary Design of an Experimental World-Circling Spaceship,” the first report ever produced for the US government on the possibility of building and launching a satellite into Earth orbit.
On May 14, 1948, RAND became an independent, non-profit corporation. But all of its contracts would come from the Air Force. RAND was a weird beast. Its first director, Frank Collbohm, even resisted suggestions of seeking contracts from the Department of Defense. “Civilians come and go,” Collbohm stated. “The Air Force is forever.”
Salter continued working on the satellite issue through the late 1940s. “The Air Force Air Staff then decided that the first phase of the Air Force satellite program should be to resolve four critical areas,” Salter explained in an interview for historian Cargill Hall. “One area was the reliability of electronics. The next area was space power. Another area was attitude stabilization and guidance systems. And the fourth area, of course, was a TV-based reconnaissance system.”
“The $64,000 question was what could you see from outer space,” Salter said. “We had access to NBC,” which had its primary West Coast studio only a short distance from RAND’s building in Santa Monica, and a transmission tower on Mount Wilson. Salter went to KNBH in Hollywood and took the station manager out to lunch. “We conjured up this idea of mocking up a satellite loop just using the station's equipment. You know, we could beam stuff up to Mount Wilson and then broadcast it back, pick it up and record it on the kinescopes.” The station manager agreed and so the RAND and RCA engineers did their experiment. “And we did this on the basis of a one martini lunch,” Salter joked. “I went out to a local store and bought a couple of Fairchild mosaic aerial maps, so we could see what a degraded image would be, which we then would turn over to a photo interpreter—a PI—and see what he could make out of it.”
Later on, Salter conducted even more of the experiments using different kinds of maps degraded to different amounts. “In fact, actually, I was a TV producer status for about a year and a half,” he said. NBC sent him publicity material for its new television shows. Salter found this amusing. “I didn't even own a television,” he laughed.Project Feed Back made the case for a satellite, demonstrating that it was capable of doing things that a) needed to be done, and b) could only be done by a satellite in orbit.
Salter and others at RAND continued these studies and by 1948 they produced another major study for the Air Force titled “Utility of a Satellite Vehicle for Reconnaissance.” Although a far more substantial study than the previous narrowly-focused reports produced by RAND since 1946, was still a limited document. It was only 138 pages long, and complex subjects, such as the external environment affecting the electronic components, were discussed in only a few sentences. Salter and Jack Lipp edited this report as well.
The Air Force leadership was not ready to approve a satellite program in 1948, but they were sufficiently impressed with RAND’s work that they continued funding it. Over the next several years RAND produced a number of smaller reports on different parts of the satellite challenge. Then, by 1954, they produced a major summary of their work, a study known as “Feed Back” because it would send intelligence data back to Earth.
The Project Feed Back study was formally presented to the Air Force on March 1, 1954. It was edited by Lipp and Salter, but included contributions from over 195 other people. Some of those who contributed to the report were already well-known in the space field, or were on the way to making names for themselves. Former Air Force Chief Scientist Louis Ridenour, then working for Douglas Aircraft, contributed to the report. Fred Whipple served as a consultant on meteors, which were considered to be a useful indicator of the density of the upper atmosphere. Lyman Spitzer consulted on celestial mechanics. Bruno Augenstein and David Griggs, who had just left his job as the second Air Force Chief Scientist, were at RAND and contributed to the report. Engineers and scientists from Westinghouse Electric, North American Aviation, and the Radio Corporation of America also worked on the report.
Once again, Lipp and Salter spearheaded RAND’s work. In their introduction, they outlined the recent history of RAND’s study effort, the 1946 report and the 1947 follow-up studies as well as two reports in 1951 on satellites for weather observation and reconnaissance. All of this work formed the basis for Feed Back, which consisted of two volumes totaling 288 pages. Feed Back was not just a summary of the technology needed to make a reconnaissance satellite work. It was an overview of what a satellite would do and how it would do it. The introduction stated that Feed Back provided “an integrated scheme for obtaining pioneer pictorial reconnaissance of potential enemy territory. As such it includes not only the television-equipped satellite vehicle(s), but also ground facilities for handling and evaluating information gathered.”
Feed Back dealt directly with the issues that were of utmost importance to Air Force officials, primarily, what the satellite was capable of doing. Not only was it much more comprehensive than their earlier works, but it made the case for a satellite, demonstrating that it was capable of doing things that a) needed to be done, and b) could only be done by a satellite in orbit.
Lipp and Salter stated clearly that it was “certain now that the satellite television could be used to see and recognize” all kinds of different features. These included: airfields of all sizes, and possibly indications of activities, such as the presence of large planes; industrial concentrations; large plants, and possibly some indication of their type; harbors and facilities such as drydocks and the presence of large ships; transportation, power and communications networks, including bridges, canals, power lines and switching yards for trains; urban areas; large military installations; and cloud patterns and structure in considerable detail.Salter and Lipp were not simply present at the creation of the field, in many ways they were responsible for it. Truly pioneers of national reconnaissance.
The first part of the report addressed the types of intelligence information that could be collected by the Feed Back satellite. Salter and Lipp conceded that the satellite would produce pictures that were barely acceptable for photo-interpretation and many that contemporary photo-interpreters would not consider acceptable at all. The scale of acceptable conventional photographs was 1:80,000 or better. But the scale of the very best Feed Back images that could be obtained would start at 1:100,000 and get worse. Furthermore, just as looking through a telephoto lens reduces the amount of the scene that you can see, this 1:100,000 scale imagery would mean that less area could be seen—perhaps only a square one and a half miles on a side.
Lipp and Salter also proposed the creation of a “central intelligence center” for interpretation and dissemination of the imagery. Such a centralized facility was necessary both for economy and to bring all of the limited expert photographic talent in the country together, under one roof, so that they could share information.
The Feed Back report was a major milestone in the development of American satellite reconnaissance. The report led to the creation of an Air Force satellite reconnaissance program, which later split into several different development efforts after Sputnik.
By that time Salter was working for Lockheed and had played a major role in the development of the Agena upper stage vehicle that eventually boosted a majority of American reconnaissance satellites into orbit. The story of how he ended up at Lockheed is itself a great tale—Lockheed had won the initial satellite contract, but the company soon lost many of its top engineers who left to form a startup electronics company. Lockheed leadership, particularly Louis Ridenour, who had worked on Feed Back, after being scared by a young Air Force contracting officer, went and raided RAND, scooping up nearly the entire RAND brain trust that had been working on satellite reconnaissance for the better part of a decade. Salter was one of the prize gems in the package.
Salter left Lockheed in 1958, the same year he obtained a master’s degree in nuclear physics from UCLA. In 1965 he obtained his Ph.D. in the same field, also from UCLA. He appears to have worked in the nuclear field, possibly on projects related to the generation of electricity for spacecraft using nuclear power, one of the original technological challenges that he had identified in his early RAND years. In the 1980s he also apparently did some work on the Strategic Defense Initiative.
Although less is publicly known about Jack Lipp, his name and Robert Salter’s name appeared on virtually all of the early American studies of satellite reconnaissance. They were not simply present at the creation of the field, in many ways they were responsible for it. Truly pioneers of national reconnaissance.