Category Dreams, Technology, and Scientific Discovery

Nuclear weaponry and the cold war

The United States and Soviet Union were in the midst of the 30-year cold war. By mid-1958, both possessed proven capabilities for producing nuclear weapons and for delivering them by one means or another to the other country. And both were near-paranoid in their suspicions of the other.

Thus, both were urgently examining potential capabilities for detecting the det­onation of nuclear test devices by the other country, and for protecting themselves against atomic bomb attacks if they should occur. In the United States, air filters to remove radioactive debris from the air and airborne water had been developed by the

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Подпись:Naval Research Laboratory (NRL) as early as 1947.1 Beginning in late 1948, several weather reconnaissance B-29 squadrons routinely patrolled over the Pacific Ocean with those air filters to assist in detecting Soviet test detonations. The first Soviet nuclear detonation, referred to as Joe-1 in the United States and as RDS-1 in the USSR, and occurring on 29 August 1949, was first detected by ground and airborne air and rain filters of that type. The Weather B-29s that I was flying for weather reconnaissance over the Pacific Ocean during 1952 continued that nuclear detonation monitoring effort as an add-on classified mission objective.

Beginning as early as July 1957, our country relied heavily on the Distant Early Warning Line (DEW Line), a network that eventually grew to 63 radar and commu­nications stations built across northern Canada and Alaska to provide early detection of any Soviet aircraft or missiles that might be headed for the United States.

The Soviets announced their successful test of an Intercontinental Ballistic Missile (ICBM) on 26 August 1957. That demonstrated an improved capability for launching nuclear weapons against the United States.

With that new information, Nicholas C. Christofilos, a physicist working on magnetic fusion at the Lawrence Livermore National Laboratory (LLNL, operated by the University of California, Berkeley), became greatly concerned that the Soviets might try to conceal a sneak ICBM attack by detonating a nuclear device beforehand at high altitude. The ionospheric effects and the synchrotron radiation resulting from spiraling electrons produced by the blast might cause radio interference that would severely limit the range at which the DEW Line could see approaching missiles. Conceivably, that particle shell might completely blind the radars.

With the launch of Sputnik 1 on 4 October, Christofilos’ concern heightened. He believed that the new Soviet capability placed the United States in near-term peril. Building on his experience with magnetically confining charged particles, he came up with the idea of depositing and storing huge numbers of electrons in the Earth’s magnetosphere to make a defensive shield. The source of the electrons would be a large number of nuclear explosions at high altitude.

During October and November 1957, he discussed that possibility repeatedly with Herbert F. York, then director of the LLNL. According to York, Christofilos even predicted the existence of the naturally occurring trapped radiation before it was discovered by stating, during those discussions, that “there are already high energy (MeV range) electrons trapped there!” He believed that cosmic rays hit­ting the Earth’s atmosphere produced, among other things, neutrons; some of those moved radially outward and decayed, and a fraction of those were trapped in the magnetosphere.2

Christofilos thought that an electron shell, if produced by the United States, might serve as a defensive electromagnetic shield against Soviet ICBMs. If dense

CHAPTER 13 • ARGUS AND EXPLORERS IV AND V 361

enough, it might heat the outer surfaces of approaching ICBMs to make them bright enough targets for heat-seeking defensive missiles. Beyond that was the possibil­ity that a sufficiently dense shell (produced by perhaps thousands of megatons of nuclear detonations per year) might directly damage approaching missiles or their warheads. They might even prematurely and harmlessly trigger incoming nuclear bombs.

His concept became known as the Argus Effect, and the endeavor to test it became known as the Argus Project.

The university scene

The government’s support of veterans’ education via the G. I. Bill following World War II forever changed the character of university education in the United States.1 It

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Подпись:enabled thousands of veterans to go to school who would not otherwise have been able to do so. By 1947, veterans made up 49 percent of U. S. college enrollment. By the end of the bill’s coverage in 1956, 7.8 million veterans attended universities, colleges, trade schools, and business and agriculture training programs.

The bill brought to the campuses a whole generation of intensely focused students whose war experiences had given them a much different outlook than that of typical prewar students. Being older than most of the traditional students, many brought along wives and young children.

To accommodate returning married G. I.s and the other student families, many universities built small villages to house them. Eight such villages of three types were built at the University of Iowa. Representative of the first type was Hawkeye Trailer Village on Old Iowa Field on the east bank of the Iowa River (near where the University Library now stands). It contained 128 trailers, whose inhabitants shared communal showers and washhouses. Ernie and Mary Ray occupied one of those units for a while. The trailers, however, did not hold up well, and by the time we arrived in 1953, the university administration had decided to remove a trailer whenever it required repairs of $50 or more.

More substantial Quonset huts and corrugated sheet metal barracks in other villages were tremendously successful. The military surplus round-topped Quonset huts held up well and had more complete facilities, including in-house showers. Les and Marilyn Meredith lived in one of those in Riverside Park, located along North Riverside Drive near the present Art Building.

Rosalie and I considered ourselves fortunate to live in one of the slightly larger half-barracks, located just west of the original University Hospital building in what was known as Finkbine Park. Templin Park, the last of those temporary villages, was razed in 1975 in favor of more permanent brick-and-mortar housing units, as the ancient custom of marriage only after college was largely outmoded by then. The site of Finkbine Park is no longer recognizable, being now a part of the university’s huge medical and sports complex.

The University of Iowa counted a total enrollment of fewer than 10,000 students in 1953 when I started, and passed that mark while I was there. By 2008, the enrollment has surpassed 30,000. When I was there, class sizes were small by today’s standards—I can recall no class larger than 200, and classes that large were rare. Classes for physics and engineering majors ranged from a few to no more than 25. One-on-one sessions with faculty members outside the classroom on short notice were nearly always possible.

Compared with the more traditional single students of the prewar era, the older married students had less time and energy for social and other nonacademic campus activities. Their families, with the need for paying employment to help support them, lent a

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new focus and sense of urgency to the university experience. Although fraternity and sorority life was still present, it was not a part of the university experience for most of the married students.

To highlight the difference, my father, while a bachelor in his senior year in 1921 at Western Union College in LeMars, Iowa, participated actively in the Decameronian Literary Society (vice president, debates, orations, lectures, and plays), Science Sem­inar, band, glee club, Young Men’s Christian Association, and the Cleric organization. He considered those activities to be important elements of his classical liberal arts education.

There were times when I regretted not having had more time for that type of extracurricular activity, but the responsibilities of a growing family, the need to work to supplement my G. I. Bill income, and my different interests at that stage in life took precedence. Still, I never felt cheated. The undergraduate curriculum in physics at Iowa embodied a well-balanced mix of the technical, historical, and philosophical aspects of physics, along with exposure to world history, ancient and modern literature, English language structure and composition, the German language, mathematics, and the creative arts. The only area in which I regretted the lack of more training and experience was in oration, including open debate on nontechnical subjects. Nevertheless, I emerged from my undergraduate years with an excellent classical liberal arts education. [11]

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Подпись:Study Program. That seemed to offer experience with a company that might help me decide upon a specific direction for my postgraduate work. As an added fac­tor, both Rosalie and I wished to live closer to her family on the West Coast for a while.

That inquiry led to a letter of acceptance by Lockheed, with the understanding that I would work at their installation in Palo Alto—full time during school vacations and about half time during school semesters. The two year appointment would include salaried work in their facilities, and they would pay my tuition and other expenses at any suitably accredited university. My hope was that I would attend Stanford University, but I learned that the deadline had already passed for application to their very limited Industrial Students Program. That meant that I would have had to travel between Palo Alto and the University of California in Berkeley. The thought of commuting a distance of 35 miles each way through heavy San Francisco Bay traffic completely repelled me. It would have made it impossible for me to have the type of strong campus interaction that I enjoyed at Iowa.

In mid-April, I rather reluctantly rejected their offer. The basic idea remained alive, however, until late summer. During a vacation trip to visit Rosalie’s family in the Seattle area in early September, I described the work I was doing to a physics faculty member on the University of Washington campus. At the end of my summary, he asked, “Why would you want to go anywhere else than Iowa?”

That clinched it—I dropped any further thought of leaving the University of Iowa. Needless to say, I have been eternally grateful that I stayed.

George H. Ludwig

I was born in Sharon Center, Iowa, a tiny crossroads cluster 10 miles southwest of Iowa City. My life until the time of high school graduation was centered on the small Ludwig farm near Tiffin. At about age 11, flying and electronics began to consume much of my free time. During my high school years, many of the Tiffin residents came to depend upon me for repairing their ailing radios and household appliances.

Immediately upon graduating from our small high school in 1946, I volunteered for service as a private in the U. S. Air Force. Serving for a year as an enlisted man, then for a year learning to fly in aviation cadet school, I received my wings and second lieutenant bars in July 1948. During four and half more years as a multiengine pilot, a squadron electronics officer, and other assignments, I was exposed to an ever-broadening range of experiences and satisfied my lust for travel.

Rosalie F. Vickers traveled with her family from Tacoma, Washington, to Biloxi, Mississippi, to marry me in July 1950. At that time I was attending radar school. Dur­ing the next two-plus years we enjoyed a nomadic military life at posts in New Mexico, Idaho, and California. Our first daughter, Barbara Rose, was born in February 1952.

I had always strongly believed that I needed a university education. Several efforts to pursue that goal as an air force officer proved fruitless, so I felt compelled to leave the active military service. On 18 December 1952, Rosalie, our 10-month-old daughter, and I departed from my final duty station in Sacramento, California, with only a very general concept of what the future might hold. When we arrived back at my boyhood home in Iowa, I had no income-producing job and very little money. Our second child was on her way. Van Allen’s offer of a position in the Cosmic Ray Laboratory was a godsend.

This book chronicles my university years, progressing through our family’s arrival in Tiffin in mid-December 1952, the birth of our daughter Sharon Lee in 1953, the receipt of my B. A. degree in February 1956, the birth of our son George Vickers in 1958, the receipt of my M. S. degree in February 1959, the birth of our fourth child, Kathy Ann, in August 1960, and ending with receipt of my Ph. D. degree a few weeks later.

Along the way, I helped in designing and building eight of the earliest U. S. Earth satellite instruments and in the use of the four of them that reached orbit.

As my final graduation approached, I accepted a position with the then-forming Goddard Space Flight Center (GSFC). Moving with my family to Silver Spring, Maryland, in Septem­ber, I formed and directed an instrument development section in Frank McDonald’s Fields and Particles Branch. From then until 1965 my work included development of a progression of satellite and space probe instruments, service as project scientist for a series of Orbit­ing Geophysical Observatories, and participation in the rapidly evolving scientific research program.

Subsequent positions included director of the Information Processing Division at Goddard and a move to the National Oceanic and Atmospheric Administration (NOAA) in 1972 to set up and direct an Office of Systems Integration in the National Environmental Satellite Service. My work in NOAA included establishment of the Geostationary Operational Environmental Satellite system and the TIROS-N polar orbiting system and, subsequently, direction of the operation of the two systems.

In 1980, Rosalie and I moved to Boulder, Colorado, andNOAA’s Environmental Research Laboratories (ERL). After a period as the ERL director, I returned for a short term at the

CHAPTER 2 • THE EARLY YEARS

headquarters of the National Aeronautics and Space Administration (NASA), where I retired from government service in 1984.

Various consulting roles, work as a research associate at the University of Colorado’s Laboratory for Atmospheric and Space Physics, and an assignment as a California Institute of Technology Visiting Senior Scientist at NASA Headquarters occupied my attention for the next seven years. In 1991, I retired from all further work in the space arena, and Ros and I made our retirement home near Winchester, Virginia.

My work in the Cosmic Ray Laboratory evolved rapidly over the three years of my undergraduate schooling. My earliest work included general laboratory work on a variety of test instruments. The first substantial task of note was to design and build a new type of marker pulse generator. At the same time, I helped Joseph (Joe) E. Kasper in building the differential analyzer (an early analog computer) that was the basis for his master’s degree.1 As time progressed, in addition to instrument development and construction, I oversaw more and more of the daily operation of the laboratory, including organizing and ordering supplies and supervising some of the student aides.

And I quickly edged into the fine art of building balloon and rockoon instruments. Figure 2.1 shows me with some of my early work.

Rockoons

The SUI rockoon program culminated in a pair of field exercises that were supported as a part of the IGY endeavor. The ambitious expeditions were undertaken in the fall of 1957 by James Van Allen, Larry Cahill, and their coworkers.

Cahill’s rockoon magnetometer While still at the Applied Physics Laboratory, Van Allen had been aware of an invention by M. Packard and R. Varian, a proton free-precession magnetometer.21 That instrument was intrinsically capable of making very precise measurements of the magnitude of a magnetic field—its precision was believed to be sufficient to make a clear distinction between the Earth’s strong main magnetic field and very weak magnetic fields hypothesized to result from electrical currents in the ionosphere. Members of Van Allen’s group at the Applied Physics Laboratory and researchers at the Naval Ordnance Laboratory conducted several searches for those ionospheric currents during the very late 1940s and the opening of the 1950s by the use of flux-gate magnetometers.22 The possibility of using the more precise proton free-precession magnetometer for that purpose, although attractive, was not pursued then.

The idea resurfaced in early 1954, when Van Allen suggested to the Upper Atmo­sphere Rocket Research Panel that the free-precession magnetometer might be used in the search for the ionospheric currents.23 At his fall 1954 meeting with his graduate students at Iowa, Van Allen outlined that basic idea and suggested that such a project might be undertaken by one of them by developing a miniaturized version that would fit within the physical envelope of a Loki rocket. If that could be done, the instrument could be carried at low cost to a sufficient height to detect the currents.

CHAPTER 4 • THE IGY PROGRAM AT IOWA

Larry Cahill, as mentioned earlier in connection with the 13 March 1956 balloon flight of his magnetometer, had joined the Iowa research group in 1954 and agreed to take on the challenging new developmental project.

Competing launch vehicle proposals

Three paths were initially advanced for reaching the U. S. goal of launching a satellite. Those were (1) a relatively heavy payload to be launched with the air force’s Atlas Intercontinental Ballistic Missile, (2) an extension of the army’s Jupiter Intermediate – Range Interballistic Missile (IRBM) development program by Wernher von Braun’s group at Huntsville, Alabama (Orbiter), and (3) a launch vehicle based on the navy – managed Viking and Aerobee-Hi sounding rockets (Vanguard).

Atlas With its origin in the early 1950s, and with the initiation of its all-out high-priority development in May 1954 following the first U. S. fusion nuclear bomb

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Подпись:tests, the Atlas was being developed as the first U. S. Intercontinental Ballistic Missile (ICBM).

In 1955, when the satellite launch vehicle debate was unfolding, the air force put forth a proposal for a 150-pound satellite to be launched by the Atlas rocket. They considered that weight to be the minimum payload required to perform the exper­iments that they envisioned. They emphasized that the Atlas would ultimately be capable of placing hundreds, or even thousands, of pounds into orbit. Furthermore, it would use proven components, use only two stages, subject the payloads to rela­tively low acceleration forces, and offer the advantage over the other two proposals of simplicity of design. They acknowledged clearly, however, that it would not be pos­sible for them to launch even a minimal satellite without interfering with the ICBM development, because of competition for facilities, propulsion sources, and skilled personnel.

An additional negative factor was that the first test flight of the Atlas was not due until well into the IGY period, and its availability in time for a satellite launch before the end of the IGY was questionable. There was also concern that use of the country’s primary ICBM missile for the IGY satellite might confuse the desired distinction between the country’s military programs and the nonmilitary IGY research endeavor.1

The Atlas made its first (unsuccessful) test flight on 11 June 1957, and partly successful test launches were achieved by September 1958. The first completely successful launch, with a realistic payload and traveling the planned distance, took place on 28 November, over a year after the Sputnik 1 launch. Three weeks later, on 18 December 1958, an Atlas B was placed in Earth orbit as Project SCORE. That “Christmas Satellite” caused a major sensation by broadcasting a prerecorded Christmas message from President Eisenhower.

The Atlas eventually became a true workhorse of the spacecraft-launching stable, first for air force military and intelligence missions, and then for National Aeronautics and Space Administration (NASA) space exploration missions.

It is a fascinating note of history that each of the first two space-faring countries used the launch of a payload into Earth orbit as the first public demonstration of the prowess of their ICBMs. The Soviet Sputnik 1 launch occurred only six weeks after the first fully successful R-7 ICBM test launch, and the Atlas SCORE launch occurred only three weeks after the first successful Atlas ICBM launch.

Since the Soviet Sputnik launch was achieved about 14 months before the U. S. SCORE launch, it led to a public perception that the USSR was ahead, not only in missilery, but by extension, in the whole broad arena of technology. That proved to be not true, as even at that time, the United States had a strong lead in missile guidance and general electronics technologies. Overtime, the advantage of the initially superior Soviet lifting capability was overcome by the U. S. lead in other high technologies. It

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resulted, in a little over a decade, in the United States placing humans on the Moon’s surface, while the Soviets had to abandon their efforts to do so.

Hermes, Redstone, Orbiter, and Jupiter C Wernher von Braun’s team moved from Fort Bliss, Texas, to the Redstone Arsenal in Huntsville, Alabama, in 1950. That group formed the Guided Missile Development Division in the army’s Department of Ordnance. It was reorganized as the Army Ballistic Missile Agency (ABMA) in February 1956 following the Department of Defense approval of their Jupiter program.

The group’s first task at Huntsville was to develop the Hermes rocket. Over time, that rocket evolved into the Redstone IRBM. Both were easily recognized descendents of the German V-2 rocket, which had demonstrated its technical soundness and utility through over 60 firings in Texas, plus two flights with Women’s Army Corps (WAC) second stages (called Bumper rockets) from Cape Canaveral, and one flight from the deck of the aircraft carrier USS Midway.

Although the exact date of origin of the Redstone project is indistinct, the Redstone name was attached on 8 April 1952. The Redstone missile made its first test flight in August 1953 and its first successful full-range flight in January 1954.2 By the time of the president’s announcement in July 1955 of the U. S. intent to mount a satellite effort, eight Redstone test launches had been made with varying degrees of success. By the time of the Sputnik launch in October 1957, 19 additional test firings had occurred, and all but 4 of those performed successfully. By then, the missile was approaching operational deployment status. That deployment was made to Europe in June 1958.

Von Braun’s eyes had been set toward space since his early rocket flights in Ger­many during the 1920s and 1930s, and even during the wartime V-2 development at Peenemtinde. After he and his team came to the United States following World War II (WWII), and while their primary work under army auspices was being directed toward the development of short – and intermediate-range military rockets, he and his associates continued to dream of rocketing into space.3 4

Thus, from early in the Redstone development at Huntsville, von Braun was think­ing of using it to launch a satellite. Ernst Stuhlinger, his senior scientist, recalled, “Sometime in 1952, von Braun remarked to me: ‘With the Redstone, we could do it.’—‘Do what?’ was my answer. ‘Launch a satellite, of course!’ And then, he de­scribed how three small stages of solid propellant rockets on top of a Redstone, ignited when the rocket had reached its apex point, could put a small satellite into orbit.”5

While that idea languished for some time within all governmental circles, enthu­siasm for space flight was growing in other arenas. For several years beginning in about 1952, the American Rocket Society (ARS) and the British Interplanetary So­ciety featured articles on possible launching rockets, satellites, and the mechanics of interplanetary flight.

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Подпись:It was in late 1953 that several far-thinking individuals became increasingly con­vinced that the time had come for more concrete action. In June 1954, Commander George W. Hoover at the Office of Naval Research and Frederick C. Durant III, pres­ident of the International Astronautical Federation, convened a meeting in the navy’s old temporary wooden building T-3 on Constitution Avenue. That meeting included von Braun, Ernst Stuhlinger, Gerhard Heller, Rudolf Schlidt, and several others from Huntsville; as well as Fred L. Whipple (chairman of the Department of Astronomy at Harvard University); S. Fred Singer (physicist at the University of Maryland); David Young (Aerojet General Corporation); and Alexander Satin (chief engineer in the Air Branch of the Office of Naval Research). Hoover opened the meeting with the words, “Gentlemen, the time has come to stop talking and start doing. We will now go ahead and build a satellite.”6

Von Braun proposed using the Redstone rocket and a three-stage Loki cluster as the satellite launcher. The Loki was a simple antiaircraft rocket being routinely produced by the Aerophysics Corporation. The launcher’s second stage would consist of 24 Lokis, the third stage would use 6, and the final stage would consist of a single Loki with a five pound satellite payload. His concept was immediately embraced by the meeting attendees.

Fred Singer and some of his colleagues in Britain had suggested, as early as 1952, a 100 pound scientific satellite, which he called the Minimum Orbiting Unmanned Satellite of the Earth (MOUSE). At the 1954 meeting, it was clear that that large a satellite could not be lofted with currently available technology. Nevertheless, Singer was enthusiastic about the proposed five pound satellite program as a first step.

The overall concept that emerged from that meeting was code-named Project Slug to help keep it out of sight of the many who were heavily involved in military politics. The idea was presented to the Chief of Naval Research soon after the meeting. After study there by Milton W. Rosen and John W. Townsend Jr., he gave official approval for further investigation and authorized conversations between the navy and von Braun’s group at Huntsville.

On 3 August 1954, the navy representatives went to Huntsville for a meeting with then-colonel Toftoy and von Braun to discuss further details. Following that meeting, Toftoy went to Washington for a discussion with Major General Leslie Simon, the assistant chief of Army Ordnance. Simon stated that he would work with the navy on this project provided it would not slow the army’s missile weapons programs. The chief of naval research followed that by giving the Office of Naval Research’s Air Branch authority to proceed with preliminary studies. During those interactions, the name “Project Orbiter” emerged, and Commander Hoover became its project officer.

It was agreed that the army group at Huntsville would be responsible for the complete launching vehicle, while the navy would design the satellite and provide

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the Naval Research Laboratory’s (NRL’s) Minitrack system, other ground tracking facilities, and logistics support and would acquire the data. It was expected that they would be ready for a launch in 1956 from an island near the equator.

In September 1954, von Braun and some of his coworkers prepared a paper, “A Minimum Satellite Vehicle Based on Components Available From Missile Develop­ment of the Army Ordnance Corps.” The paper, submitted to army authorities as a classified document, provided many details of the design, performance, and operation of the suggested system. The paper asserted that a five pound satellite could be built with components available from their weapon developments. He suggested that a joint army-navy-air force “Minimum Satellite Vehicle Project” be established.

It was some time later that the Huntsville engineers suggested that the Redstone rocket might be upgraded by lengthening its tanks and substituting hydyne for alcohol as the fuel. With those changes, they believed that a satellite weight of 15 pounds could be orbited.

The efforts to sell the Orbiter concept continued on other fronts. On 24 November 1954, the ARS Space Flight Committee that was mentioned earlier submitted an open proposal based on the Orbiter concept. Titled “On the Utility of an Unmanned Earth Satellite,” it was submitted to the U. S. National Science Foundation (NSF). The proposal stressed the use of such a satellite in studies of astronomy, astrophysics, biology, communications, geodesy, and geophysics. Although the NSF did not act on the proposal, being preoccupied with other planning for the upcoming IGY, the ARS continued to promote the idea using its own resources.

William Pickering and his staff at the Jet Propulsion Laboratory (JPL) were brought into the Orbiter planning as a full partner after the ABMA and NRL sent their proposal to Pickering for JPL’s review in late 1954.

The evolving proposal was submitted to Assistant Secretary of Defense Donald A. Quarles, in charge of army research and development, on 20 January 1955. Recog­nizing the growing interest in launching satellites within all three of the U. S. military services, and of growing indications of a similar interest in the Soviet Union, Quarles, instead of acting on the proposal, established a new Ad Hoc Committee on Special Capabilities chaired by Homer J. C. Stewart. The committee came to be known as the Stewart Committee. Its task was to recommend which of the competing U. S. proposals ought to be supported.

An important decision was quietly made internally by the U. S. National Committee for the IGY on 14 March 1955 that the United States should initiate a satellite program. However, no public announcement of that decision was made, and it was only later that the Orbiter proponents learned of that decision.

Even as the Stewart Committee was being formed, planning for Project Orbiter continued. One feature of the Redstone-based launch vehicle was that it could be

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Подпись:launched from a fully mobile launch platform that could be set up in short order at any location. In April, the Office of Naval Research began planning for a launch site survey in the Gilbert Islands in the Western Pacific. They planned that the survey expedition would depart in the spring of 1957, and that the actual Orbiter launch could take place in midsummer or the fall of that year.

Orbiter came to an abrupt end as an officially sanctioned project in September 1955, when the Stewart Committee made its recommendation and the Army Policy Committee and Quarles made the decision to proceed with the Vanguard launcher.

The Redstone rocket had a range of several hundred miles. The army needed a longer – range missile, and the Huntsville group proposed a 1500 mile IRBM in July 1955. Planning progressed throughout the rest of 1955, culminating in full approval of the program in December of that year and its official designation as the Jupiter program in April 1956.7

The first two phases of the Jupiter flight-testing program employed Redstone – based configurations to make early tests of certain critical new Jupiter technologies and components. Although built upon the Redstone rocket, they were considered part of the Jupiter development program and carried the Jupiter designation. Among other reasons, that kept them high on the priority list for procurements, and for testing at Cape Canaveral.

The first of those test configurations was called the Jupiter A. It made its first preliminary firing in September 1955 and its first fully successful flight to test the Jupiter inertial guidance system six weeks later. Over the Jupiter A lifetime, ending in June 1958, 25 vehicles were fired to test various components of the Jupiter IRBM. Twenty of those were mission successes, two were rated as partial successes, and only three failed.

Among other things, it was proposed that the Jupiter missile program use a new concept for dissipating the heat generated as the nose cone carrying the warhead reentered the atmosphere. The air force had adopted a heatsink approach for its ICBM. That depended on the absorption of the heat of reentry by a large mass of metal on the nose cone’s leading surface. The army team recognized that use of a high-temperature insulating ceramic on the nose cone offered the possibility of achieving the same result more economically. Ablation—conversion of the solid material directly into vapor as it heated—would carry away the reentry heat with a much smaller weight penalty.

The ablation approach represented completely new territory. Rather than incurring the delay, expense, and uncertainty of waiting to test that new concept by live firings of the full Jupiter missile after it became flight worthy, a new Redstone-based configura­tion was devised to provide a much earlier and lower-cost test, using readily available components. That second Jupiter test configuration, introduced into the program in

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mid-1955, was known as Jupiter C—standing for Jupiter-Composite. It was often referred to as the Reentry Test Vehicle (RTV). Permission and funds were obtained to build a dozen Jupiter C vehicles for that purpose

Not surprisingly, the RTV looked like an incarnation of the Orbiter launcher! It consisted of the Redstone first stage, plus two of the three upper Orbiter stages. The originally proposed Loki rockets were replaced in August-September 1955 by a smaller number of somewhat larger rockets, following a suggestion by Homer Stewart at JPL. The so-called scaled-Sergeant rockets were an outgrowth of JPL’s contract with the army to develop the Sergeant IRBM. The reduced size test rocket was built so that early developmental tests could be made on candidate formulations for the Sergeant rocket fuel. They were six inches in diameter, and 11 of those small rockets formed the Jupiter C second stage, while three made up its third stage.

The RTV (Jupiter C) configuration, though inelegant, was remarkably simple and robust. Three firings were made as a part of the Jupiter nose cone-testing program. The first, to demonstrate the soundness of the multiple-stage design, took place on 20 September 1956, over a year before Sputnik 1 was launched by the Soviets. For that launch, Von Braun was explicitly directed not to include an active fourth stage, to ensure that it would not “end up in space” and preempt the Vanguard program. In fact, the Pentagon brass, being fully aware of the great passion of the Huntsville group for space flight, sent a monitor to Cape Canaveral for the express purpose of ensuring that a live fourth stage was not “accidentally” mounted on top of the assembly. The payload for that first test consisted primarily of sand to simulate the weight of a scaled Jupiter nose cone. That test was fully successful, with the inert payload achieving a maximum velocity of about 12,000 miles per hour, a height of 682 miles, and a range of 3400 miles.

It was clear to all involved that a live final stage could have achieved orbit.

Two more flights of the Jupiter C carried scaled nose cones as their payloads. One on May 1957 was a partial flight success, with the missile taking an erratic course because of a guidance system malfunction. The nose cone from that flight lit at sea too far from the planned impact area to be recovered. A brilliantly successful third flight took place on 8 August 1957, with the nose cone being recovered and publicly displayed by President Eisenhower.

The success of that flight demonstrated the validity of the ablation-type nose cone design, and the nose cone-testing program ended. Nine remaining sets of Jupiter C hardware were in various stages of construction but no longer needed for their original purpose. Some of them were carefully stored “for any possible future use” (i. e., for launching satellites).

Aerobee, Aerobee-Hi, Viking, and Vanguard As the V-2 program in Texas was winding down in the late 1940s, the two stage Aerobee rocket was developed to provide

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Подпись:a vehicle for continuing the country’s upper atmosphere scientific research program. It was developed by the Aerojet General Corporation and Douglas Aircraft Company under contracts from the Navy Office of Research and Inventions (predecessor to the NRL). Funding was provided by the U. S. Navy Bureau of Ordnance.

James A. Van Allen, at the Johns Hopkins University’s Applied Physics Labo­ratory, was a major instigator and overseer for the Aerobee program. He provided technical oversight throughout its development and early use, and prepared some of the instruments for Aerobee flights until he left Johns Hopkins in late 1950.

The completely assembled Aerobee, with its booster, main rocket, and nose cone, measured a little over 26 feet in length and 15 inches in diameter, with a gross weight at launching of 1068 pounds.8 Unguided, it was capable of carrying 150 pounds of payload instruments in a nose cone about 88 inches long by 15 inches in diameter at its base. During launch, the solid stage booster carried the rocket to a height of about 1000 feet, where the liquid-fueled main engine ignited. The 45-second thrust of that main engine, followed by its coasting after burnout, carried the rocket to its peak height.

The Aerobee enjoyed a remarkable record of performance in the U. S. suborbital high-altitude research program.9 Its first static test firing occurred on 25 September 1947, quickly followed by the first successful launch of an instrumented payload on 24 November. Most of the early Aerobees were launched from the army’s White Sands and nearby Holloman Air Force Base range facilities near El Paso, Texas. Five flights were made from two cruises of the USS Norton Sound. By the time of the Stewart Committee decision on the satellite launcher in August 1955, 55 Aerobees had been launched.

The Aerobee continued for a long time as a true workhorse—as of 17 January 1985, 1037 had been fired for a wide variety of investigations in atmospheric physics, cosmic rays, geomagnetism, astronomy, and other fields.10 The majority of the successful research flights achieved peak altitudes of from 40 to 65 miles, depending on payload weight and other factors. A record height of over 91 miles was achieved by U. S. Air Force flight 56 on 15 June 1955.

In response to a continuing need for even higher performance, an extension of the Aerobee rocket was developed, again, expressly as a carrier for upper atmospheric scientific research. Design and development began in 1952, when the navy and air force began working together with the Aerojet General Corporation. The resulting rocket retained the basic two-stage Aerobee design, but improved on the thrust-to – mass ratio of the main stage, increased the efficiency of the thrust chamber, and added more propellant.11

It was built in two versions, both designated Aerobee-Hi. The air force version, sometimes called the Air Force-Hi, was contracted in 1952, under direction of the Air

CHAPTER 7 • THE U. S. SATELLITE COMPETITION 185

Force Cambridge Research Center and the Wright Air Development Center. The navy version, likewise occasionally referred to as the Navy-Hi, was contracted in 1953, with direction from John W. Townsend Jr. of the NRL. The two versions were much the same, but the navy version contained more propellant. The air force version could carry a payload of 120 pounds to 160 miles, or 150 pounds to 145 miles. The navy version could carry 120 pounds to 180 miles, or 150 pounds to 170 miles.

The overall length of the navy Aerobee-Hi rocket, including both stages and the nose cone, was about 31 feet, and it had a diameter of 15 inches. The payload configuration was similar to that of the Aerobee—an approximately 88 inch long nose cone could accommodate up to 150 pounds. As with the Aerobee, there was no active guidance—a slow roll provided lateral stability.

At the time of the Stewart Committee’s Vanguard decision in August 1955, the Aerobee-Hi was just coming on line. The air force had test-fired two of its versions, and the navy made its first flight on 25 August.

The Aerobee-Hi rocket, too, had a distinguished record. By mid-1957, six air force launches had been made (including four test flights), and four flights achieved heights of over 100 miles. By the same time, the navy had launched 13 of theirs (including four test flights), and 7 of them reached heights of over 100 miles.

A rocket considerably larger than the Aerobee was developed for further expansion of upper atmospheric research. The NRL, under Milton Rosen’s leadership, contracted production of the rocket with the Glen L. Martin Company. The rocket was originally dubbed the Neptune, but that name was changed to Viking to avoid confusion because the navy was developing an aircraft named Neptune.12

Twelve Viking firings were made by the time of the Stewart Committee’s decision in 1955. Its record of success was outstanding throughout. There were no rocket-only developmental flights—all 12 carried instruments for upper atmospheric research. The first, launched in May 1949, achieved a height of 50 miles. Number 8 failed during a static firing. All others reached altitudes of from 31 to over 150 miles. Number 4 was fired from the afterdeck of the USS Norton Sound in May 1950 to a height of 104 miles. The others were launched from the White Sands Proving Ground in Texas.

The various launches included instruments for upper air pressure, temperature, density, winds, ionization, and composition; Earth photography; and solar and cosmic radiation studies. Especially notable firsts included the measurements of positive ion composition at an altitude of 136 miles on Viking number 10 in May 1954, and cosmic ray measurements at an altitude of 158 miles on Viking number 11, also in May 1954.

The Viking was believed at the time to be the most efficient rocket in existence. However, because of its high replication cost of about $450,000, it never became a pervasive feature of sounding rocket research. By the time of the satellite launcher

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Подпись: 186deliberations, two more Vikings remained on hand out of the original purchase and were offered for use in the Vanguard program.13

In 1954, when the possibility of launching an Earth satellite was growing in the United States, and especially after President Eisenhower announced his decision to launch one in 1955, the suggestion was advanced by a group at the NRL under John P. Hagen’s leadership that a combination of the navy-developed sounding rockets be used to launch it.

That concept, named Vanguard, would employ an improved version of the Viking rocket as a first stage, a modification of the main stage of the Aerobee-Hi as a second stage, and a solid propellant rocket as a third stage. As stated above, the Viking had already achieved an enviable record of success, the Aerobee was in regular service, and the Aerobee-Hi was successfully entering service. The development of a suitable third stage was believed to be a simple extension of the currently available technology.14

The fully assembled Vanguard launch vehicle was to be 72 feet long and 45 inches in diameter at its thickest point, with an all-up weight of 22,000 pounds. The first stage Viking would burn a mixture of alcohol and gasoline, with liquid oxygen as the oxidizer. Its thrust was to be 27,000 pounds during a burn of 140 seconds. Its motor was mounted in gimbals and steered to maintain the desired flight path.

The second-stage Aerobee-Hi derivative was to be powered by nitric acid and hydrazine. Its motor was also gimbaled for steering. Auxiliary jets provided stabiliza­tion during the coasting phase and spun it on its long axis just before final third-stage ignition. The second stage contained the control system for all three stages.

The second-stage nose cone contained the third-stage solid fueled rocket and its satellite payload. The third-stage rocket was unguided, but the spin imparted by the second stage averaged out variations in the thrust of its motor to keep it on a straight course.

The written Vanguard proposal included extensive content related to the devel­opment and building of the research instruments. That benefited greatly from the experience at NRL in building and flying scientific instruments in its sounding rocket programs. It was also proposed that a navy-developed system would be used for satel­lite tracking and data transmission. That would be a derivative of an instrument devel­opment in the Viking program—the Single-Axis Phase-Comparison Angle-Tracking Unit, later known as Minitrack.

The first countdown attempts

Countdowns were started during the two evenings before the successful launch. Wernher von Braun later recalled the general situation during the first attempt. He was in the Pentagon near Washington, D. C. General John B. Mederas, director of Huntsville’s Army Ballistic Missile Agency (ABMA) and von Braun’s immediate

245

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Подпись: 246boss, was also there, along with Pickering and Van Allen. A later account by Von Braun reads:

On the evening of January 29, our firing party was assembled at Cape Canaveral. Dr. Kurt H. Debus and Dr. Hans F. Gruene, two veteran missile men, were in charge of the firing, and the JPL was represented by Dr. Jack Froehlich. Almost everyone was there except Bill Pickering, Jim Van Allen and me. We’d been ordered to Washington to meet the press after the launching had been announced.

It was a personal blow to me not to be able to be at the scene. But, I did keep in touch with the men in the blockhouse on several open telephone lines.

The first night was dreadful. Winds of 165 miles per hour began blowing at an altitude of 40,000 feet. We had to postpone the firing.1

The next day, I had more time to scout the situation, and discovered that members of the Vanguard team from the Naval Research Laboratory (NRL) had been there for some time preparing for a Vanguard launch. They had made an earlier launch attempt on 6 December, but, amid high expectations and intense publicity, their rocket had exploded on the launch pad.

The Vanguard team was working hard, by now with much less publicity, in preparing for their next attempt. A new countdown had progressed to within a few minutes of ignition a few days earlier, when they had been forced to abort. They continued to run into one delay after another, until the decision was made on 27 January to allow our Jupiter C to launch ahead of them.

I had worked closely over the previous two years with NRL’s Roger Easton and Marty Votaw while developing our Vanguard instrument, and we enjoyed a very pleasant and productive working relationship and personal friendship. They had set up a Vanguard receiving station at the Cape in Hangar S to support their own project, and had checked out their receiver to verify that it could decode our Deal I signals.

Roger and Marty graciously invited me to join them. Thus, through their hospitality and goodwill, I found a place aside from any JPL facility to track the performance of my Deal I instrument during its second and third countdowns. I vividly recall the three of us sitting on stools at a workbench in their laboratory. I listened to the telemetered signals from my instrument while, at the same time, hearing the progress of the countdown from a loudspeaker connected to the Cape’s intercom system.

For the second countdown, I began writing down in my notebook the information from the cosmic ray counter, as it sat atop the launch vehicle. After every 32 pulses from the GM counter, the telemetered tone shifted. I simply wrote down the time of each transition. As it turned out for that second attempt, I happened to start recording the data just four minutes before the countdown was scrubbed.

CHAPTER 9 • THE BIRTH OF EXPLORER I

The first countdown attempts

FIGURE 9.1 The Jupiter C launch vehicle with the servicing gantry still in place during the early evening of 31 January 1958. At about 30 minutes before launch, the gantry was moved back. The vehicle successfully launched Explorer I. (Courtesy of the NASA Marshall Space Flight Center.)

That happened at 6:55 PM EST. Quoting again from von Braun’s account:

The next night was worse. The winds were up to 225 miles per hour. Again, we had to postpone. And the predictions were for days more of the same.

Data tape logistics

Ground receiving stations would be recording tapes at locations around the world. Considerable coordination was necessary to arrange for shipping the expected large numbers of tapes within and across the national boundaries and to ensure that all three parties involved, NRL, JPL, and us experimenters, would be able to read the tapes reliably once they were received.

It had been arranged from early in the Vanguard planning that the Minitrack tapes would be sent from the ground stations to the NRL Computing Center in Washington, D. C., for cataloging, quality checking, and duplication. On 18 December 1957, soon after the Deal project was approved, Henry Richter at JPL called Jack Mengel at NRL to arrange for JPL to receive the Deal I telemetry tapes directly from the Minitrack ground stations, so that JPL could analyze the payload engineering data.27

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Подпись: 306By early January, it was time to nail down the detailed assignment of responsibilities and to ensure that all arrangements and procedures were in place.

It was then, too, that I heard of a suggestion by one of the JPL scientists that they be allowed to reduce and analyze the SUI cosmic ray data. I became alarmed that, with the immensely larger resources at JPL, they would be able to analyze the data and announce significant findings before we would be able to do so at Iowa. We had always assumed that the principal investigator and his staff (Van Allen and I) would have first rights to the data and that all information about the performance of the cosmic ray instrument and scientific results would come from us.

I alerted Van Allen to that development during the first week in January. Fortunately, he was attending a meeting of the TPESP on Tuesday, 7 January, where he had an opportunity for an extended private discussion with Pickering. That evening, Van penned a note to me that conveyed some of the results of their conversation:

(a) He [Pickering] agrees on having a meeting in the near future (during next week) on the problem of sorting out raw data from the two Juno flights [Deal I and II] among: SUI, AFCRC, and JPL. He will arrange a meeting in Pasadena with Cormier, Manring, an NRL representative, JPL persons concerned, and you (representing SUI, i. e., getting the C. R. data to SUI as promptly and as completely as possible).

(b) Pickering says to forget the Snyder proposal for reducing and analyzing our C. R. data at JPL. This proposal got “out of hand” and has no status whatever. All C. R. data will be handled as the exclusive property of SUI.28

Upon his return to JPL, Pickering took immediate follow-up action. First, he arranged a meeting to work out the details for handling the data for the entire Deal project (Deals I and II). That meeting, with Albert (Al) Hibbs as chairman, took place on Thursday, 16 January. Attending the meeting were John F. Bedinger and Frank Dearborn (Geophysics Research Directorate, AFCRC); L. N. Cormier (National Academy of Sciences); Whitney Mathews (Vanguard, NRL); JPL participants Phyllis Buwalda, Al Hibbs, B. D. Martin, Marcia Neugebauer, John C. Porter, and Henry Richter; and me.29

The agreements reached at that meeting called for JPL to serve as the central collecting agency for all low – and high-power data tapes, including those from their own Microlock receiving stations, the Vanguard Minitrack stations, and recordings made by amateur radio operators. The one exception was that, for reasons described below, the Deal II high-power recordings would be sent directly from the Minitrack stations to NRL’s Vanguard Processing Center in Washington.

At that time, we also received a status report on the readiness of all ground stations. The following stations were reported as ready to support the Deal I launch: [9]

CHAPTER 11 • OPERATIONS AND DATA HANDLING 307

• JPL Microlock stations at PAFB, Florida; Earthquake Valley, near San Diego, California; Singapore; and Ibadan, Nigeria

• San Gabriel Valley Microlock amateur radio station at Temple City, California (other amateur radio stations were anticipated)

Additional stations were activated before the Deal I launch actually took place. Those were at JPL (Microlock); San Diego (Minitrack); Antigua, British West Indies (Mini­track); Blossom Point, Maryland (Minitrack); Lima, Peru (Minitrack); and Tokyo, Japan (conventional). That made a total complement of 17 stations for recording the Explorer I data.

Amateur radio operators were to notify JPL and NRL by postcard of the amount and quality of their recorded data. Science coordinators would distribute a listing of available amateur radio tapes, and tapes desired by the engineers and scientists would then be requested of the amateur radio operators. As it turned out, although radio amateurs provided highly useful tracking data, they provided very few recordings of telemetry, other than those of the San Gabriel Valley club.

As tapes arrived at JPL, their first task was to play them to produce long paper charts on Sanborn strip-chart recorders. Those multiple-pen chart recordings displayed all channels of the telemetered information, plus time information that had been recorded with the data at the receiving stations. The strip-charts were used by the staff at JPL (with oversight by Conway Snyder and major support from Phyllis Buwalda) to assess the overall performance of the satellites, including the general quality of the cosmic ray and micrometeorite data, and to obtain readings of the internal temperatures of the instruments.30 Copies of those strip-charts were sent to the experimenters. We used ours to quickly assess the quality and content of the scientific data. The copies sent to AFCRC gave them their micrometeorite data.

The second task at JPL was to copy selected tracks from the original station tapes onto magnetic tapes for the two sets of experimenters. Those for Iowa were produced on one-quarter inch, two-track magnetic tapes.

The Deal II onboard tape recorder could be interrogated only by the Vanguard Mini­track stations. It was agreed that the University of Iowa would be the central agency for handling all data from the Deal II high-power transmitter, since only our cosmic ray data were conveyed by that system.

The recordings of those high-power signals were sent from the Minitrack stations directly to the Vanguard Computing Center, on Washington’s Pennsylvania Avenue. There paper strip-chart recordings were produced, so that the NRL engineers could monitor and control system operations. They also made duplicate recordings of se­lected tracks, again on one-quarter inch, two-track magnetic tapes. Both the one-half

OPENING SPACE RESEARCH

Подпись:inch originals and the one-quarter inch duplicate recordings were sent to SUI, along with copies of their strip-charts.

In summary, for all Deal I and II continuously transmitted data, we at SUI were to re­ceive from JPL (1) one-quarter inch, two-tracktape recordings containing the detected output from the GM counter channel, plus a time reference and voice announcements; (2) reproductions of the JPL strip-charts; (3) reduced internal temperature data; and (4) copies of the payload calibration books. From the Deal II high-power system, we were to receive the recordings and strip-charts from NRL.

The AFCRC experimenters were to receive, for all Deal I and II continuously transmitted data, half-inch, four-track tape recordings containing the outputs from the high-power transmitters, the low-power transmitters, and timing and voice informa­tion, plus copies of the same JPL strip-charts, reduced internal temperature data, and payload calibration books that we would be receiving.

The January meeting produced other miscellaneous agreements, including specific procedures and standards. As an example, it was agreed that all times would be recorded in Greenwich Mean Time (GMT) to avoid confusion.

A time delay of four days between satellite passage and receipt of the strip – chart records and tapes at Iowa was projected before launch. That delay lengthened considerably after launch as the immensity and complexity of the data-handling task became apparent. In fact, many of the recordings did not reach us until several weeks after they were recorded.

Some of the above arrangements were modified after we, collectively, had gained experience in handling the Explorer I data. At a meeting at JPL on 11 and 12 March, Van Allen requested funds for SUI to procure a one-half inch, seven-track recorder with characteristics matching those at the receiving stations, so that we could work directly with the original recordings and eliminate JPL’s tape-duplicating step. After we acquired the seven-track tape deck, a change in procedures was made that included circulating the original ground station magnetic tapes between JPL, AFCRC, and SUI. That reduced the workload at JPL and speeded the delivery of data to the two experimenter sites. Similarly, after that improved tape deck was placed in operation, we were able to work directly from the recordings of Explorer III data dumps produced by the Minitrack stations.

The initial plan was to permanently archive the original continuously transmitted data tapes at JPL. After the change in the tape-handling procedures mentioned above, SUI became the permanent archive site for all of the Explorer I, III, and other follow-on SUI experiments. Those original tapes still exist (in 2010) in the former Van de Graff

CHAPTER 11 • OPERATIONS AND DATA HANDLING particle accelerator vault located under the front lawn of the old Physics, Astronomy, and Mathematics Building on the University of Iowa Campus. Arrangements are being made by the University of Iowa Libraries, Department of Special Collections to digitize those tapes and maintain them in long-term storage.

Pickering’s second action upon his return to JPL after his January discussion with Van Allen clarified any lingering question about the analysis of the experimental data. On his instructions, a memo was issued that stated, simply:

It has been decided that no data analysis of cosmic ray counts or meteorite impacts obtained from Project Deal will be done by the Lab. Data reduction will be done in accordance with agreements made by you [Al Hibbs] and the experimenters, Van Allen and Dubin. The Data Reduction Lab may scan the data for obvious inconsistencies, but no analysis of this will be performed.31

The Argus effect and project

Theory fell far short of being able to predict the results of such high-altitude explosions—tests were needed. Major questions for the Argus Project included pos­sible ionospheric effects, whether the nuclear detonations would form detectable charged particle shells, what the trapping efficiency might be, and how long the trapped particle shells might persist.

In late 1957 and early 1958, a special urgency attended the conduct of such tests because of the growing possibility of a nuclear test ban treaty being considered by the United States and USSR. That ban was, in fact, placed in effect by the United States for a limited period beginning on 31 October 1958.

The President’s Science Advisory Committee reviewed Christofilos’ proposal, and on 11 March, the Armed Forces Policy Council charged the LLNL with undertaking further theoretical work and with making recommendations related to the nature of such a possible nuclear test.3

By late April, the decision was made to proceed with the test as a major national undertaking. The operational and technological management of the project was vested in the new Advanced Research Projects Agency (ARPA, later renamed Defense Research Projects Agency, or DARPA) of the Department of Defense. ARPA was formed on 7 February 1958 (with Herbert York as its first chief scientist) as a direct consequence of the Soviet launches of the first Sputniks. Its stated mission was simply to keep U. S. military technology ahead of the nation’s enemies (including preventing another event like the Sputnik surprise). Argus was the organization’s first major assignment.

Shortly before the Armed Forces Policy Council’s direction to LLNL, the Jet Propul­sion Laboratory’s (JPL’s) Pickering learned of the Argus thinking and suggested to the Livermore people that Van Allen was the right person to monitor the radiation resulting from the Argus detonations with satellite instruments.4 That suggestion was the real basis for setting up the special meeting at JPL on 11-12 March 1958, as mentioned in Chapter 10.

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Подпись:The attendees, in addition to Van Allen and me, included Bill Pickering, Jack Froehlich, and Henry Richter of JPL, Major General John Mederas from Huntsville, and several others. Most interestingly, Stanford University’s Wolfgang K. H. Panofsky, a figure new to us, was there. Panofsky had been working closely with Christofilos on his ideas for the Argus tests.

Although the meeting was openly billed as a gathering to discuss Explorer I results, those results were still so tentative that, in retrospect, a meeting of such senior personnel for that purpose was certainly premature. No one in our small Iowa team had made any outside hint of our growing suspicion that the Earth might be surrounded by a previously unknown region of high-intensity trapped radiation. The stated meeting objective was certainly a cover for its true purpose—an early examination of the possibility of orbiting a satellite suitable for detecting and quantifying the Argus Effect.

The meeting did include discussions of “techniques for building miniature detec­tors that were suitable for small satellites but capable of particle identification and the measurement of energy spectra and angular distributions,” characteristics not pos­sessed by the single Geiger-Muller (GM) counter that Van Allen and I had adopted for the early measurements.5 Although there were veiled allusions to the possibility of high-altitude nuclear weapons-related experiments, it was not until some time later that Van Allen and the rest of our team learned anything substantive about the Argus planning.

Wolfgang Panofsky, born in 1919, was a very interesting person in his own right.6 His family emigrated from Germany to the United States during the increasingly difficult times there for Jews in 1934. Pief (as he was affectionately known by his close associates) obtained his bachelor’s degree from Princeton University in 1938 and his Ph. D. at CalTech in 1942 (at the tender age of 23). He worked at CalTech during most of World War II on various weapons-related projects. In 1944, he joined Luis Alvarez’s team at Los Alamos as an employee of the University of California at Berkeley to work on nuclear weapons-related testing. In 1951, in the midst of the McCarthy inquisition, he resigned his position there in protest of the loyalty oath being demanded of University of California faculty members. He moved to Stanford University, where, in addition to his faculty position, he assumed leadership of Stan­ford’s High Energy Physics Laboratory, including its high-energy linear accelerator. It was from that environment, drawing upon his working relationships with individuals in the nuclear weapons-testing business, that he became heavily involved in the Argus Project.

By the time of the Argus Project approval in April 1958, the United States had conducted a total of about 120 live nuclear tests. All but one were detonations at

CHAPTER 13 • ARGUS AND EXPLORERS IV AND V 363

or near the Earth’s surface, underwater, or underground. The high-altitude shot in Operation Teapot in April 1955 took place at about eight miles height to study atmospheric effects. Operation Hardtack I was getting under way, and its 35 tests conducted from 28 April through 18 August 1958 included three high-altitude shots: Yucca, Teak, and Orange.

None of those four early detonations, however, was high enough to test Christofilos’ idea. The U. S. Department of Defense organized the Argus Project to test the Argus Effect before the upcoming nuclear weapons test moratorium took effect.

It should be noted in passing that Argus was the only clandestine nuclear weapons testing program ever to be conducted by the United States.

The Argus Project saw the launching of three nuclear devices on modified three-stage solid-fuel Lockheed X-17A rockets from the deck of the Navy’s USS Norton Sound (AVM-1) in the South Atlantic (in the region from 38.5 to 49.5 degrees south, and from 8.2 to 11.5 degrees west). Those three Argus detonations (in the range of one to two kilotons) took place on 27 August, 30 August, and 6 September 1958 at heights of about 124, 159, and 335 miles, respectively.7

Sometimes termed the world’s largest-scale scientific experiment, the Argus oper­ation included the deployment of an entire naval task force (Special Task Force 88) consisting of eight ships and about 4500 men. The flotilla included, in addition to the USS Norton Sound, two destroyers, two destroyer escorts, two oilers, and the aircraft carrier USS Tarawa with a number of VS-32 aircraft.

An extensive observational network was established to detect and measure the detonations’ effects. Information was needed on the formation of charged particle shells, the spectral, spatial, and temporal characteristics of the particles, the extent and duration of visible auroral effects at the north and south magnetic field conjugate points, the spectral characteristics of the emitted light, effects on radar returns, and perturbations of the Earth’s ionosphere and geomagnetic field.

The network included the seaplane tender USS Albemarle, stationed near the magnetic field conjugate point near the Azores, and sounding rockets launched as elements of project Jason from Patrick Air Force Base (PAFB) in Florida, Blossom Point, Maryland, and Ramey Air Force Base in Puerto Rico. Additional monitoring aircraft flew from Lajes Field in the Azores. A special network of ground observatories was established by the Air Force Cambridge Research Center.

It was realized from the beginning that observations from orbit by Earth satellites would be essential in obtaining the required spatial and temporal data coverage. Two satellite programs were established to meet that need. The Explorer IV and V program, described here, was designed to meet the dual objectives of investigating our newly discovered, naturally occurring high-intensity radiation and the Argus Effect. But there was an additional satellite program.

OPENING SPACE RESEARCH

Collegial interactions

One of the most important features of research in the 1950s was the highly supportive network of collegial relationships that existed on the local scene, nationally, and internationally. Larry Cahill accurately characterized the working of our small, tightly knit cosmic ray group when he wrote:

George, Carl [McIlwain], Ernest [Ray], and I were graduate students; Frank [McDonald] and Kinsey [Anderson] were post-doctoral research associates. We worked in close proximity in the basement of the old Physics building, discussed our work and problems, went to lunch and coffee breaks together, and shared a sense of challenge and excitement as we prepared to go out and make measurements. Frank and Kinsey managed the lab and the students and were very accessible for advice. In overall charge of our enterprise was Professor James Van Allen, self-described as the “scoutmaster.” He determined the direction of the research and found support. He also provided the graduate students with research projects. He was busy with teaching and administrative duties, as Department Head and director of the research lab, but was always available for advice on major problems and for long-term guidance.

Of the greatest value for research training was his policy of giving each student as much responsibility as the student could handle.2

CHAPTER 16 • SOME PERSONAL REFLECTIONS 435

Equipment development was done in a crowded room about 60 feet square in the south end of the Physics Building basement. Various of us gathered for frequent informal discussions. Lunch provided a special opportunity for taking stock and exchanging ideas. It was a fairly regular practice for someone to cruise the halls as lunchtime approached to see who wanted to go out on that day. Collecting a group of three or four, we frequented nearby places such as the Jefferson Hotel Dining Room and Joe’s Bar. The lunchtime discussions usually focused on our work of the moment, with strong emphasis on the interpretation of data.

Departmental colloquia and seminars served as more formal and broader venues for exchanging information. In addition to giving us the opportunity to expose, defend, and debate our own ideas, they were a means by which we kept up to date on the work of the other students, faculty members, and visiting scientists.

The value of that environment cannot be overstated. Information flowed freely, with no thought of hiding ideas to protect individual intellectual property rights. That cooperative spirit was promoted by Van Allen’s and the other senior faculty mem­bers’ scrupulous attention to recognizing all contributors when publishing scientific results.

It should be added that in spite of the spirit of openness and professional collegiality, there was always an appropriate distinction between faculty members and students. After all, they were helping to train us, and were always responsible for correcting our errors and judging our progress.

Attendance at off-campus professional gatherings was well supported. Nearly every­one, faculty and students alike, whose paper was accepted for a conference was able to attend. Students sometimes went, even if they were not presenting papers, when the agenda was closely related to the person’s research.

The most active professional societies during that period were the American Geo­physical Union (AGU), American Physical Society, and (of special interest to me) the Institute of Radio Engineers (now the Institute of Electrical and Electronics Engi­neers). Other conferences of special note were sponsored by the National Academy of Sciences, especially during the planning, conduct, and follow-up to the International Geophysical Year (IGY).

AGU was especially important, being by far the most helpful in fostering the exchange of early space research results. The organization quickly published pa­pers and letters containing early space research results in its Journal of Geophysical Research. At first, AGU’s periodic and special conferences were accommodated in the Great Hall of the National Academy of Sciences. Within a short time af­ter the beginning of the IGY, the expanding conferences were split between that venue and the neighboring State Department auditorium. Overlapping sessions soon

OPENING SPACE RESEARCH

Подпись:became necessary. Even then, it was still possible for a person to know most of the attendees.

To this day, I look upon AGU with special fondness and consider it my home professional society.

Another venue for interaction deserves special mention. As stated earlier, cosmic ray research was remarkably vigorous long before the IGY. In the United States, most cosmic ray research was centered on a few university campuses and in several defense laboratories, with a strong concentration in the midlands.

In response to a perceived need for increased intercampus discussion, Marcel Schein of the Ryerson Physical Laboratory of the University of Chicago organized the first Mid-West Cosmic Ray Colloquium in 1948 or 1949. One of Van Allen’s first acts upon his early 1951 arrival in Iowa City, working in close collaboration with Schein, was to plan and host the second of those meetings. That occurred on 7 April 1951, only a few months after his arrival. Other leading organizers of the earliest colloquia included Enrico Fermi and John A. Simpson of the University of Chicago; Edward P. Ney, John R. Winckler, and Phyllis P. Freier of the University of Minnesota; and J. G. Retallack of Indiana University.3

After 1956, those meetings were referred to as conferences instead of colloquia, in recognition of their expanding scope and audience. Throughout their lifetime, the stated purpose of the Mid-West Cosmic Ray colloquia and conferences was to involve the various active research groups in informal exchanges on the latest progress in the field and to discuss interpretive ideas. Although the early emphasis was on cosmic rays, the conferences broadened over time to include most of solar system particles and fields research, as that field blossomed during and following the IGY.

The very earliest colloquia were fairly leisurely, one day affairs, but they quickly grew to occupy two very crowded days. They typically included a series of substantial prearranged addresses by senior researchers, followed by extended open discussions. Those were accompanied by numerous short communications on current progress by attending researchers, including students. Later meetings tended to be more topically organized. The conferences were informal, with only sketchy agendas and no written proceedings. Papers were generally noncitable—in fact, most of the presentations were made from brief notes and lantern slides, and full manuscripts were rarely distributed.

As far as I could determine, the series ended with the colloquium at Iowa City in 1968, by which time the subject matter was being increasingly assimilated into the agendas of the AGU and other professional societies.

Those conferences played an especially important role for us students by helping us learn how to put information together and present it in a cooperative and supportive

CHAPTER 16 • SOME PERSONAL REFLECTIONS 437

environment. They also helped to establish a spirit of collegiality, helpfulness, and adventure within an extended but focused group of researchers. To my knowledge, that type of regular, relatively informal intercampus information exchange has never since been replicated in the space research arena.

The work during those early years involved our close association with three major government-supported organizations: the Naval Research Laboratory (NRL) in the District of Columbia, the Army Ballistic Missile Agency (ABMA) at Huntsville, Alabama; and the Jet Propulsion Laboratory (JPL) in Pasadena, California. My rela­tionship with all three continued throughout my professional career, as they became major components of the National Aeronautics and Space Administration (NASA) when it was formed in October 1958.

There were subtle differences in the attitude conveyed by the three organizations. The Huntsville group, under von Braun’s leadership, was clearly consumed by the idea of getting into space, regardless of who got the credit. At one point, they offered to use their Jupiter C vehicle as a Vanguard launcher, even to the point of putting the word Vanguard on its side. They yielded their interest in building the first Explorer satellites to JPL, even though they had completed substantial initial design work at Huntsville. Throughout that period, Von Braun insisted that the questions of roles and missions was secondary to the end goal of launching satellites.

The NRL personnel were equally generous. Although they had gained official authorization to launch the first U. S. satellite, they provided great assistance to the Army program once it was approved. That included teaming up on data recovery, tracking, orbit determination, data processing, and the sharing of electronics know­how. It even included providing satellite transmitter and receiver designs and hardware for the Army efforts.

The people at the JPL were more guarded. We admired their capabilities, but, as inferred in Chapter 9, they wanted it known that they were the satellite builders. Whereas the Vanguard and Huntsville people regarded us at the university as true partners, JPL tended to look upon us as suppliers. In our long-term dealings with those three organizations and their later NASA embodiments (the Marshall Space Flight Center at Huntsville; the Goddard Space Flight Center at Greenbelt, Maryland; and JPL in Pasadena), Marshall and Goddard have been more willing to accept experimenters’ instruments as submitted, as long as they passed all of the mu­tually agreed-upon tests. JPL, on the other hand, tended to look upon the instru­ments as objects procured under contract and subject to their own full engineering oversight.

In summary, JPL possessed a stronger measure of “institutional arrogance” than the others. Having said that, we experimenters developed many long-lasting and highly rewarding relationships with the JPL people.

OPENING SPACE RESEARCH

The summer 1953 rockoon expedition

After the initial development and field proof of the rockoon technique in 1952, Van Allen, his students, and Gottlieb were eager to put this new tool to further use. Expeditions were mounted in the summers of 1953, 1954, 1955, and 1957 to exploit that new capability. The focused goal of the one in 1953 was to extend the 1952 observations to a larger latitude range and to obtain more information about the nature of the particles.

Les Meredith prepared a set of rockoons that were generally similar to those he flew in 1952, including the use of the same Deacon jet-assisted-takeoff-based rockets. Larger Skyhook balloons (up to 100 feet in diameter) were selected to increase the altitude of the rocket firing to as high as 70,000 feet (over 13 miles), thus permitting peak rocket altitudes of well over 300,000 feet (57 miles). A cutoff device was added near the balloon’s neck to drop the rockets for safety reasons if, after a few hours’ flight, the balloons descended below 30,000 feet or the rockets did not fire. His total payload weights were 30 pounds, 2 pounds heavier than the 1952 payloads.

Student Robert (Bob) A. Ellis Jr. had helped with the rockoon work from the beginning but elected in 1952 not to commit to them for his thesis work. When it was time to prepare for the 1953 expedition, however, Bob had become a convert and wholeheartedly joined that endeavor. He prepared rockoon instrumentation to measure total cosmic ray ionization.

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The summer 1953 rockoon expedition

FIGURE 2.1 A25-year-old George Ludwig in 1953, not long after beginning workin the Cosmic Ray Laboratory. Here I am wiring and checking timing circuits for an upcoming rockoon expedition. I felt like a kid who had been turned loose in a toy store.

 

His instrument was generally similar to his 1952 instrument, as shown earlier in Figure 1.3 (b). The complete array of instruments is shown as they were prepared for shipment in Figure 2.2.

For that second rockoon-launching expedition, I received my introduction to the art of rocket instrumentation by helping both Les Meredith and Bob Ellis assemble their packages. The extended field operation, sponsored by the Office of Naval Research (ONR) and Atomic Energy Commission as Project Muskrat, took place during July, August, and early September 1953 aboard the U. S. Navy icebreaker USS Staten Island.2 The State University of Iowa (SUI) expedition members were Mel Gottlieb as team leader and students Meredith and Ellis. They were assisted by the always – capable and valuable support of the ONR’s Lieutenant Malcolm Jones.

Boarding the icebreaker USS Staten Island at Boston, the Iowa threesome set up a trailer laboratory on the helicopter flight deck. A Naval Research Laboratory (NRL) group led by Herman E. LaGow also boarded with their rockoons and receiving

CHAPTER 2 • THE EARLY YEARS

The summer 1953 rockoon expedition

FIGURE 2.2 Equipment for the 1953 rockoon expedition, ready for shipment. The instru­mented nose cones are stacked on top of wooden frames containing the 18 tail fins. Meredith’s nine instruments are in the near-field, with the nose cones beside them, while Ellis’ nine instru­ments are to the rear. The electronic firing assemblies (on which I had been working in Figure 2.1) lie at the bases of the instruments. One empty Deacon rocket casing lies atop the firing gondola frames. (Courtesy of the Department of Physics and Astronomy Van Allen Collection, The University of Iowa, Iowa City, Iowa.)

station to measure upper-atmosphere pressure, temperature, and density. His flights marked the beginning of rockoon flights by that organization.

The SUI contingent established a milestone in racial desegregation on that sailing. It was customary for the Navy to accord civilian researchers officer rank when on board their ships. When the Iowa group arrived in Boston, the ship’s crew discovered that Bob was black. The only blacks on board the ship in the past had been as members of the nonofficer crews—blacks had never been admitted to “officer country.” After due deliberation, the captain went ahead and housed Bob in the officer’s quarters and admitted him to the other officer’s facilities. Bob became an instant hero of the black crew members.3

The ship sailed from Boston harbor on Saturday, 18 July, and progressed toward Newfoundland and the Labrador Sea. After an initial failed launch attempt late on the first day, they tried igniting a firing charge suspended under a captive balloon off the ship’s fantail and concluded (probably erroneously) that they had installed the igniter backward for the first launch attempt. While three more unsuccessful rockoon flight attempts were made during the following day, the team worked feverishly to determine the cause of the problem. That first try at 6:30 AM, after meticulous verification that the igniter was properly installed, failed. The next try was with a bag of smokeless powder next to the igniter. That also failed. They thought their problem might be that

Подпись: 26Подпись:
OPENING SPACE RESEARCH

a Bakelite plug in the rocket motor might have blown out when the rocket reached altitude. A third try to test that theory at about 6:00 PM also failed. That evening, they wired Van Allen to see if he could throw any light on their difficulties.

The ship traveled in poor visibility past the coast of Newfoundland during most of Monday. That morning, the researchers devised a rig with a cluster of small weather balloons to make a flight test of the firing box and igniter. Instead of the precious rockoon instruments, that flight used a radiosonde transmitter and receiver of the type used widely for meteorological sounding. Late that afternoon, they launched that flight but were further frustrated when the radiosonde’s shipboard receiving station failed.

Meredith worked all that night to build another variation on the small-balloon test system. For that test, another firing box was coupled to one of the rockoon flight transmitters, and the rockoon receiving station was set up to receive its signal. By Tuesday afternoon, although the ship was rolling about 10 degrees and the wind speed was near the maximum speed of the ship, they were able to attempt a launch of this new setup. Because of conditions, it was difficult to measure the balloon lift, and some of the balloons received small holes because of the difficult balloon-handling operations. The assembly rose only a few thousand feet before it drifted out of range.

At that point, the team decided that a vacuum chamber test might be informative, since the igniters had been designed originally for use at ground level. Finally, they hit pay dirt—that test on Tuesday evening with a vacuum chamber that Herman LaGow had brought along showed that the firing squib was blowing the igniter’s main

CHAPTER 2 • THE EARLY YEARS

The summer 1953 rockoon expedition

FIGURE 2.4 A rockoon on its way aloft, shortly after release from the deck of the icebreaker USS Staten Island during the 1953 expedition. The balloon envelope is only partly full here, but its helium expanded to completely fill it as it climbed into the rarified air at rocket-firing altitude. The firing gondola can be seen directly below the rocket’s tail fins. (Courtesy of Leslie H. Meredith.)

powder charge apart without burning it in the rarified air where the rockets were being expected to fire. They thought at first that they would pressurize the rocket, but that proved too difficult to do reliably in the field. Finally, on Wednesday, Lieutenant Jones devised a new arrangement, with a wire screen to reinforce the igniter’s plastic case and with black powder strung on the igniter’s hot wire. The black powder burned when the wire was heated by a firing current, and that ignited the main igniter charge. That field invention (referred to afterward as the Jones Igniter) worked well throughout the rest of the expedition.

Les Meredith’s informal expedition notes make very interesting reading, both in de­scribing an Arctic field expedition and in conveying a highly personalized impression

28 OPENING SPACE RESEARCH

of the problems, excitement, and sense of adventure. His entry on their first day out, Saturday, 18 July 1953, elaborates on some of the initial operational and programmatic difficulties, starting with their departure from Boston:

Last night about midnight, the ship got some messages that it was to proceed to Saglek, Canada, “without delay.” We were supposed to leave this morning on our project. The sailing time was set at 9:00 A. M. In the literal meaning, the ship was to proceed to Saglek and shoot our rockets later. Gottlieb was all for getting off the ship and coming home. Since the ship was leaving at 9:00, however, there was not time to get everything packed so we stayed. It turned out the captain is a reasonable type of person and he was willing to delay the ship an hour or so to get a rocket off, but he could not sit and wait if there was a wind, or it was night, etc.

Today the wind has been only about five mph and it’s been a beautiful cloudless day. As a result, we were able to get one of Ellis’ [instruments] off about 5:30 PM. We had to wait that long so we would be far enough out. We left Boston about 9:15 AM and steered right along at about 14 knots all day. Ellis’ didn’t fire. We were able to watch the balloon with naked eye for over two hours. Then it got dark. It was just a small white spot and hard to find and keep track of. This evening we put the firing charge on a captive balloon off the back of the ship and blew it up with our firing mechanism. We figured out we had put it in the rocket backward.4

The ship arrived at Saglek Bay on the northern Labrador coast (about 58.5 degrees north geographic latitude) during the early morning of Thursday, 23 July. By that time, they had discovered the reason for their earlier problems and had high expectations that the next launch would be successful. But, since they were close to shore, rock – oon launches were not advisable. Les’ entry for that day described a day of forced relaxation for the researchers:

This has really been a day and a half. This morning we got up to find ourselves anchored at the end of Saglek Bay. The weather was beautiful. With a sweater, it was about right in the shade and a little warm in the sun. There were a few clouds and a slight breeze. The only drawback was the great number of large mosquitoes and flies. The morning was largely spent waiting for the afternoon.

In the afternoon, we took a landing boat to the beach. There was an abandoned army base there. All that was left was a barn and lots of empty oil drums. We hiked inland and climbed a mountain which was at least 2000 feet high. With my sweater on, I worked up a good sweat. Then we came down and walked along and fished in a clear mountain stream. In one pool, there were three or four large rainbow trout. They wouldn’t bite so we first threw rocks at them and ended up swimming in the pool. It was three or four feet deep and fifteen by twenty feet across. The bottom consisted of a large slab of rock, no sand or mut [mud?]. There were rapids at both ends. Then we came back to the ship. There was grass in places, a few low shrubs, and many different types of flowers including dandelions. Mostly there was what looked like a type of moss almost, and, of course, lots of rocks. This was especially true up on the mountain. The view from the mountain was really something. There were mountains all around and down below were the green valleys, lakes, and the ships in the harbor. There were four other ships here. The only life we saw were the fish, and some small gray birds (flies and mosquitoes). There were lots of holes in the ground, but we didn’t see what lived in them. Sunset was at 8:00 PM, EST tonight.5

CHAPTER 2 • THE EARLY YEARS

They were able to make the next launch attempt, using the field-rigged Jones Igniter, on Friday, 24 July, soon after the ship left Saglek Bay on its way toward Resolution Island. That also failed, but for a different reason—the weather worsened as they left the shelter of the bay, so there was a residual wind across the deck when the rockoon was released. The firing box was knocked off the load line during its initial ascent when it snagged on a flight deck net.

That incident highlighted an important aspect of balloon launches. As discussed earlier in connection with ground-based launchings, if a balloon is inflated when the wind speed relative to the launch site is more than a few miles per hour, the anchored balloon is blown aside above the payload. If the balloon is released under those conditions, gravity causes the payload to swing under the balloon like a pendulum, and it crashes into the ground, ship, or sea, nearly always damaging the instrument.

A ship can follow the wind to mitigate this effect. The standard operating procedure was to tie a small weather balloon to the ship’s railing so that it floated 100 feet or so above the deck in full view of the conning officer. The conning officer’s task was to steer the ship and adjust its speed to keep it centered under the balloon. With that accomplished, the relative wind speed across the deck was minimized, and inflation and launch could be accomplished with safety.

Of the five unsuccessful initial launching attempts, the first and third expended two of Ellis’ valuable instruments, and others wasted three of Meredith’s payloads.

On Saturday, 25 July, the ship reached Resolution Island, located at about 61.5 degrees north geographic latitude, across the mouth of Hudson Strait from northern Labrador. For the next considerable period, the ship worked in the Reso­lution Island area. Meredith’s entry for Sunday, 26 July 1953, indicates the general nature of the ship’s primary mission:

Nothing happened again today. We sat around off Resolution Island. It was overcast all day and sprinkled off and on. The main features were the large swells, which kept the boat rocking all day.

During most of the day, we had a line from the back of our ship to the front of a larger ship, a LSD (floating dry dock). Our job was to keep the nose of this ship pointed into the swells while it put small landing boats into the water, through a door at its back. Those boats were to take supplies into a radar station on the island, as the larger boats were afraid to go in because of the ice. Whether the small boats made it, I don’t know.

There didn’t appear to be too much ice. Quite a few small pieces, but nothing big.

Rolls of 10° were common. Some were as high as 20°. One was 30°. On this one, I went right out of my chair.6

On Tuesday, 28 July, 10 days after leaving Boston, the ship was again in sufficiently open water, and the Iowa team was finally able to launch its first successful flight. Meredith’s daily entry for that triumphal day reads:

This morning we got up at 4:30 A. M. for a flight. The wind was about ten miles per hour when we started and there was a heavy overcast. It sprinkled off and on, mostly on. At about

OPENING SPACE RESEARCH

Подпись:6:30 A. M. we got the flight off. It was one of mine and had a hot wire igniter. It fired at 8:00 A. M. right on schedule. The reliability of the results is questionable. The terrible radio propagation and large aurora last night, which I didn’t see, may be related to results obtained. We’ll have to make another flight to check. When we launched, the wind was about twenty miles per hour, the maximum speed of the ship. This coupled with the fact that the General Mills load line was just barely long enough, three feet left on, which made the launching touch and go. Anyway, it went.7

Auroras occur in the upper atmosphere (predominantly above 60 miles altitude) at high northern and southern latitudes (centered at about 67 degrees north and south geomagnetic latitude). They are caused by energetic particles that are guided into the upper atmosphere by the Earth’s magnetic field. Some of those particles, those usually associated with the visibly diffuse aurora, are electrons and protons precipitating from the magnetospherically trapped particle populations (the later-discovered outer Van Allen Radiation Belt). Other particles, often associated with the more variable discrete aurora, are predominantly electrons arriving from outside the magnetosphere, primarily from the Sun.8 9

During the following days, the ship continued to work in the Resolution Island area in persistently marginal weather. But that Saturday evening, the scientists were able to talk the captain into sailing into open water to attempt another rockoon launch. During that attempt (with an NRL payload), a frightening incident occurred that could have been a major disaster. A wind gust came up after the balloon had been inflated. The balloon acted like a huge sail, and the resulting force broke the 1000 pound test line anchoring the balloon to the deck. The load line had not yet been attached to the rocket, but was lying coiled on the deck. Mel Gottlieb happened to be standing on that line when the balloon surged upward. Fortunately, he jumped free, and the line did not become entangled in his legs. If it had, the balloon would easily have borne him aloft, and they would have had no way to cut him down. That forcefully reminded everyone that shipboard rockoon launching is, fundamen­tally, a dangerous operation, and that strict adherence to rigorous safety practices is essential.

The ship remained in the Resolution Island and nearby Frobisher Bay areas for nearly two weeks, working on its primary mission to escort Navy ships through the ice. Departing there on late Wednesday, 5 August, it proceeded up the Davis Strait, across the lower end of Baffin Bay, and through Lancaster Sound to Resolute Bay (not to be confused with Resolution Island). Resolute Bay is located on Cornwallis Island, lying just northwest of Baffin Island and west of larger Devon Island. (See Figure 2.14 for the relative locations of those sites.)

More rockoon flights were made during that leg of the trip. By the time the ship reached Resolute Bay early on 10 August, a cumulative total of 10 SUI and three NRL rockoons had been launched. The icebreaker remained at Resolute Bay for some

CHAPTER 2 • THE EARLY YEARS 31

time, resuming its primary mission to support a number of ships in the icy water. Les Meredith left at Resolute Bay on 12 August via a Royal Air Force Lancaster mail plane so that he could begin his classes with the start of the new academic year. He returned to Iowa City via a circuitous path through Alert Base on the far northwestern shore of Ellesmere Island; Thule, Greenland; and Boston. The ship eventually proceeded to Thule, and then returned the rest of the expedition party to Boston on about Septem­ber 5, with the expedition teams firing six additional SUI and two more NRL rockoons along the return path.

In all, 16 launch attempts were made by the Iowa group, and 6 were made by the NRL scientists. Seven of the Iowa instruments and three of the NRL instruments reached useful altitudes and produced usable data. Three of the successful Iowa flights carried Meredith’s single GM counters, and the other four carried Ellis’ ionization chambers.

Data from one of Meredith’s 1953 flights confirmed and extended his 1952 results. Those combined results served as the basis for his Ph. D. dissertation, as mentioned at the end of the previous chapter. Ellis’ flights, made at about 76 degrees, 86 degrees, and 56 degrees north geomagnetic latitude, served as the basis for his Ph. D. dissertation, where he reported that higher-charged primary cosmic ray nuclei (charge greater than or equal to six) were absent or nearly absent at magnetic rigidities below 1.5 x 109 volts.10

As mentioned briefly in the prologue, flights measuring cosmic ray intensity typically show an initial rise in the counting rate as the altitude increases. The rate reaches a peak value when the instrument passes through the so-called Pfotzer-Regener maximum (often shortened to Pfotzer maximum). That occurs where the counter detects the combined effect of incoming primary cosmic rays that have not yet interacted with the atmosphere, plus secondary particles that result from collisions of primary particles with atoms and molecules in the atmosphere. As the instrument proceeds even higher, the counting rate drops slightly and eventually flattens to an essentially constant value. At that point, the counter is too high to see many of the secondary particles, so that it registers almost exclusively the incoming primary cosmic rays. During rocket descent, the instrument passes again through the Pfotzer-Regener maximum, and the counter rate then drops to its sea-level value, where a preponderance of the primary and secondary cosmic rays have been absorbed by the atmosphere. Figure 2.5 beautifully illustrates this typical pattern.

The constant, or “plateau,” value above the Pfotzer-Regener maximum was the primary information for which the 1952 and 1953 expeditions were mounted. The goal was to determine those plateau values for various geomagnetic latitudes, in order that the effect of the Earth’s magnetic field could be used to help determine the energy spectrum of the primary cosmic rays.

The summer 1953 rockoon expedition Подпись: FIGURE 2.5 A plot of the GM counter counting rate as a function of time for a typical rockoon flight in the absence of the auroral soft radiation. This was from flight 23, made on 3 September 1953, at a geomagnetic latitude of 55.6 de-grees north. (Courtesy of Leslie H. Meredith.)

OPENING SPACE RESEARCH

Although Meredith was dubious at the time about the quality of the data from the launch on 28 July 1953 (SUI flight 13), it turned out to be valid and resulted in an important new discovery. Launched just northeast of the mouth of Hudson Strait at about 74 degrees north geomagnetic latitude, it was the first flight to detect an anomalous radiation superimposed upon the normally expected cosmic rays, as shown in Figure 2.6. Flight of another of his instruments on 30 August (SUI flight 20) at about 64 degrees north geomagnetic latitude during the ship’s return showed a similar effect.

The data from flight 13 showed the expected counting rate during the early and late phases of the flight, where the instrument passed over the Pfotzer-Regener maximum soon after the rocket fired and again shortly before impact. But at higher altitudes, where the rate was expected to remain essentially constant, it climbed to a much higher value. The peak rate during that flight reached about four times the anticipated plateau value.

Подпись: FIGURE 2.6 Counting rate of the single GM counter as a function of time for SUI flight 13 on 28 July 1953, at a geomagnetic latitude of 74degrees north.This represents the first detection of the auroral soft radiation. (Courtesy of Leslie H. Meredith.)
The summer 1953 rockoon expedition

Because this anomalous effect was seen only during the two flights made in the neighborhood of the auroral zone, it was surmised that the observed extra radiation was linked to the production of the visible aurora. Those two flights were the basis

CHAPTER 2 • THE EARLY YEARS 33

for the original announcement in early 1955 of what was quickly termed the auroral soft radiation.11

It was tentatively hypothesized that the counters were seeing the high-energy tail of the particles producing the aurora, and that they probably were predominantly elec­trons having kinetic energies in the neighborhood of 1 MeV That early interpretation was modified after follow-on investigations in 1954 and 1955, as related later.