Proposal, ca. 1960, to launch a sectional pusher plate by rocket to an altitude of 200,000 feet, detonate a small nuclear charge, and recover the plate.
"How bad was it to take off say from the Nevada Test Site?" asks Ted. "We actually took a couple trips out there, to Jackass Flats. We didn't have to go there, I suppose. But it was exhilarating to imagine watching this thing take off, starting with very low yields because of the air, then gradually building up from like twenty tons per explosion up to a kiloton when there was no atmosphere, and more. To get out of the atmosphere it was a small number, like a hundred. A hundred nuclear explosions is not a small number, but these were very small. We kept pointing out that flying Orion through the atmosphere from the ground involved much less yield of stuff in the atmosphere than we'd already done with nuclear tests, setting off huge fission energy-release two-stage bombs."
By 1958, worldwide atmospheric testing was approaching 100 megatons per year. Tests were being conducted on the ground, in the air, underwater, and, at Bikini and Eniwetok, aboard barges, since if tests on low coral islands were continued there might not be enough of them left to constitute an atoll when testing stopped. Bombs were being placed at the tops of towers, dropped from aircraft, shot from guns, lofted by balloons, and launched into space by rockets. "In those days they were really fooling around," says Freeman. "It was just like a fireworks show, you could shoot up almost anything you wanted!" The Eisenhower-Khrushchev moratorium, announced on August 22, 1958, lasted from October 31, 1958 to September 1, 1961. There was a flurry of activity at Livermore and Los Alamos, and a flurry of radioactivity in Nevada, just before the testing stopped. "I came back at one A.M. this morning from a week at Livermore where they make bombs," Freeman reported from La Jolla on October 31, 1958. "The days I was there were the last days before the test ban went into effect, and they were throwing together everything they possibly could to give it a try before the guillotine came down. There are so many wild ideas and enthusiastic people at this place, I almost felt sorry to come back here at the end of the week."[271]
Two weeks earlier, on October 13, 1958, a memorandum of understanding had been signed between the Air Force Special Weapons Center, represented by its contractor General Atomic, and the Atomic Energy Commission, represented by the University of California Radiation laboratory, formalizing the state of cooperation between La Jolla and Livermore "in laying plans for small subsurface, surface, or high altitude tests, and particularly, for the work on 'clean,' small atomic devices."[272] It was no accident that this agreement was signed just as testing was coming to a halt. Orion supporters were lobbying the State Department for an exemption for underground tests of up to 1 kiloton and extra-atmospheric tests of up to 50 kilotons—an exemption that would have allowed both Orion and some of the wild ideas under development at Livermore to go ahead.
After the moratorium went into effect—with no exemptions—the weaponeers kept designing bombs. And the Orioneers kept making plans for a nuclear test to determine whether the ablation problem was as tractable as they thought. They had hoped to send a small bomb and a small pusher plate up into space (but not into orbit) by rocket, detonate the bomb, and recover the plate by parachute; now, instead, they made plans for a contained, low-yield explosion, either in an evacuated underground cavity or in a specially constructed vacuum tank. Would a sample pusher plate, and the associated numerical models, hold up? This was the reality check, says Freeman. "If anybody was serious about this, then you would have to do this underground test.
"The idea was we would be allowed one test shot and if that turned out well we might get a go-ahead. It was designed to be more or less contained so that you could get in there and study the debris afterward. The main point was to reduce the pressure very fast. You have an excavated cavity in the ground, with your pusher plate on one side and the bomb on the other with a vacuum in between. So you'd throw the debris at the plate, but the problem is you would get a very high pressure in the cavity and that would destroy everything. But if you could get the pressure after the explosion and the first rebound from the surface down in a few milliseconds, then the cavern could survive. So I designed a scheme where you had a huge number of balls of charcoal suspended in the chamber. They occupied a fairly small part of the volume so they wouldn't interfere much with the blast wave but as a result of the blast wave they would disintegrate and spread soot all over the chamber, which would absorb the radiation very fast.
"It was clearly not good for high-yield tests, but up to something like one hundred tons it could have worked," says Freeman, who remembers driving to Albuquerque with Ted to talk to the Air Force and AEC about conducting the test in an aboveground vacuum tank. "It was within the range we were interested in. You had a pressure of something like one thousand atmospheres, which could have blown the thing completely apart, if it wasn't immediately reduced. You filled up the whole space with charcoal dust and that soaked up the energy in about a millisecond. It would have been a nice toy to play with. The weight of the carbon was several hundred tons." According to Freeman the idea was never used, but Bud Pyatt, who remained active in the United States testing program, says, "No, it was. It was a very hush-hush test, in Nevada. It was called 'Diamond Dust.' "
After all the megatons that had been detonated in the open, it would seem that a small, contained Orion test could be conducted without raising environmental or political obstacles, and that it should be easy to distinguish between a constructive project like Orion and the business of developing more destructive bombs. There were, however, at least three military implications inherent to the proposed Orion tests.
First, the question of decoupling: whether small nuclear explosions can be decoupled from their characteristic seismic signal, making them difficult to detect. The prospects for a permanent test ban, then under intense debate, depended largely on whether such a ban could be enforced. Hans Bethe argued that it could, Edward Teller that it could not. "The public is on the side of Bethe, the facts on the side of Teller," Freeman wrote. "I have been very much in the middle of this fight."[273] Avoiding the technicalities, he announced to the readers of Foreign Affairs that it would be possible "to build a building, looking externally like a normal industrial structure, within which kiloton explosions can be contained. One may envisage a weapon testing facility bearing on the outside the inscription Kazakhstan Consolidated Steel Mills' and carrying on a legitimate business of steel fabrication as a side line."[274] The requisite hundreds of tons of charcoal could be delivered without raising any alarms.
Second, testing the effects of nuclear explosions on protected and unprotected surfaces in a vacuum would have implications for the design of anti-missile and anti-satellite weapons, and for understanding how to defend against such attacks. Third, the underlying concept of directed-energy explosions, a key element of any Orion test, had inescapable military consequences in that directed-energy devices are the only kind of nuclear weapons useful in close combat, since they can be directed away from one's own forces. These were significant questions in 1959. ARPA's initial survey of anti-missile technology concluded that "the advantages of the directed nuclear explosion are: (1) the greater lethal range, and (2) the capability of directing the explosion products so as to give some protection to friendly elements which may be nearby and which would not survive an isotropic explosion of the same yield."[275] No matter how peaceful its intentions, Orion was inextricably linked to the development of weapons. Bomb tests could be decoupled, but Orion could not.
In July of 1959, Freeman, Ted, and Brian Dunne made a visit to Jackass Flats, where, as Freeman explains, "we hoped to carry out our first crucial demonstration of feasibility with a real bomb." Although they were in Nevada to make plans for a single explosion, underground, it was impossible to stand there in the empty desert without imagining Orion's full-scale launch. "Only once in my life have I experienced absolute silence," says Freeman. "That was Jackass Flats under the midday sun. It is a soul-shattering silence. You hold your breath and hear absolutely nothing. There in the white, flat silence I began for the first time to feel a slight sense of shame for what we were proposing to do. Did we really intend to invade this silence with our trucks and bulldozers, and after a few years leave it a radioactive junkyard? The first shadow of a doubt about the rightness of Orion came into my mind."[276]
The shadow of atmospheric fallout had loomed over Orion from the start. "World-wide contamination and contamination of launch site was subheading #10 under "Task 5, Overall design integration" in the original ARPA contract. Although two months later it was noted that "no thought has been given to shielding, launching, or contamination yet," as soon as the basic characteristics of the ship and its propulsion charges were approximated, estimates of the fallout from typical missions were made.[277] These studies were deeply classified, since any specific discussion of fallout reveals technical details about the design of the bombs. For the sponsors of Orion, there was the added problem of revealing the huge number of bombs that would be involved.
Fallout had become a hot political topic in 1954, when the Castle Bravo shot at Bikini yielded more than 15 megatons instead of the predicted 6, severely irradiating a Japanese fishing boat, the Lucky Dragon, and contaminating the inhabitants of Rongelap and Utirik. Soviet tests had rained fission products on Japan, and strontium 90, with a half-life of twenty-eight years, was turning up in mother's milk and children's bones. Leaders, including Adlai Stevenson, Albert Schweitzer, Linus Pauling, the World Council of Churches, and even the pope, were calling for an end to atmospheric tests. "My mother liked Orion," says Ted. "But she didn't like the bombs."
Three broadly distinguishable forms of fallout would be produced by an Orion launch. First, radioactive material would be kicked up directly by any initial blasts near the ground. "In order to avoid contaminating surface areas and the atmosphere," it was suggested, in 1959, to use "high explosive shots to 400 or 500 feet after which small nuclear shots would be used for the rest of the atmosphere and aerospace."[278] Second, fission products would be released directly into the atmosphere by the 100 to 200 explosions it would take to get above the stratosphere, if not completely into space. Finally, there were the fission products produced once Orion was above the stratosphere, and, several hundred more explosions later, in orbit around Earth or making its departure for somewhere else.
Proposal,
ca. 1960, to launch a sectional pusher
plate by rocket to an altitude of 200,000 feet, detonate a small
nuclear
charge, and recover the plate.
Boosting Orion vehicles above the atmosphere with chemical rockets reduces the immediate fallout, and it was suggested that with later, hybrid versions of Orion the fallout problem had been solved. Space is a high-radiation environment, and there is no reason to fear that fission products that stay in space would do anyone any harm. Unfortunately for Orion, a significant fraction of fission products released anywhere in Earth's magnetosphere—not just within Earth's atmosphere—will slowly spiral in along magnetic field lines and eventually reach the ground.
This was demonstrated by a joint Los Alamos-Department of Defense test named Teak, yielding 3.8 megatons at an altitude of 250,000 feet above the South Pacific on August 1, 1958. "Teak, which we looked at very carefully, had tungsten in it, for reasons that you don't need to know," Freeman explains. "This tungsten was highly radioactive and essentially one hundred percent of it came down all over the earth over the course of many years. Very little gets away, because as long as anything is ionized it will be trapped in the magnetic field and only the neutral atoms escape. Most of the time the sunlight ionizes it and eventually it slides down the field lines into the atmosphere and comes down to the ground. The only way you could avoid this would be to launch over the North Pole where the field lines go straight out, and use very unsymmetrical bombs so you can be sure the debris is going outwards and not inwards. In that way you might be able to cut the contamination down to ten percent, but it was completely out of the question to get acceptably free from fallout this way. As far as the public is concerned ten percent is just as bad as a hundred percent."
The question for Orion, in 1959, was really two questions: how much fallout would be produced, and what would be its effects? "I remember working on the fallout problem as my main responsibility for some months," says Freeman, whose work is evidenced by at least one known (but still classified) report, Radioactive Fallout from Bomb-Propelled Spaceships, dated June 2, 1959. "We did very careful calculations, long before we had such good evidence as we have today. It's quite easy to do rough arithmetic. What you really need to know is in the case of very low doses how many rads you have to absorb on the average to kill one person. That's the important number.
"The official number at that time was 100,000. That was the official United Nations number, derived from the Hiroshima and Nagasaki statistics. It is now known that that was wrong, and in fact the correct number is more like 10,000. So it's a factor of ten worse than the U.N. said. But we knew that already, because some doctors in Glasgow had measured the effects on babies who had been exposed to X rays in the womb and they got much smaller numbers. In 1958 that evidence already existed, although the U.N. hadn't taken that into account. So we were more conservative than the U.N. and used the number 10,000, which is now more or less accepted as being right.
"At least half of the flight, assuming that we went to Mars or someplace, would be within the earth's magnetic field, so half of it would come down, and the total amount of fission products we produced were about a megaton, so we would be putting about half a megaton of fallout into the atmosphere. At that time both the United States and Russia were testing huge bombs in the atmosphere, something like a hundred megatons a year. We estimated we would be adding one percent to the existing bomb tests. Then the question is how many people were the existing bomb tests killing. That was hotly debated at that time.
"If you spread this radioactivity over the earth more or less uniformly and use this number of 10,000 person-rads per death it worked out something like a thousand people got killed every year by the existing bomb tests. This meant about ten people would be killed per mission from Orion. That was a number that I took very seriously. You were condemning something like ten people to death if you didn't do something to reduce the fallout. That to me was the real show-stopper.
"That's why I went to Livermore, because I thought we could make clean bombs. Unless the bombs were cleaned up drastically the thing really made no sense. But what I discovered when I went to Livermore was that this was more difficult than I had thought. What Livermore could do was something like a factor of ten. This was called the neutron bomb, producing neutrons without fission, and neutrons you could easily absorb. That would have meant killing one person per mission—on the edge of being acceptable considering that all these big projects kill people one way or another. From today's point of view, it's unacceptable. But in those times it wasn't so clear. I had thought we could make really clean bombs, down by at least another factor of ten. Fortunately, as it turned out later, none of the ideas that Livermore was considering worked. All the practical designs for Orion were based on ordinary fission bombs. And for me that was a fatal flaw."
Freeman left the project at the end of September 1959. The freewheeling days of physicists doing engineering and engineers doing physics were over. "It was starting to become bureaucratic," he remembers. "There were about fifty people and that's too many to have this kind of unstructured activity." The days of designing bombs on the back of an envelope, then testing them six months later in the Nevada desert or out in the Pacific were also over, not just because of the moratorium, but because of the tremendous increases in costs and institutional bureaucracy standing in the way. For the next six years, Project Orion kept chasing after that first, critical nuclear test—which kept receding from its grasp. On several occasions the project either secured the funding for a test but not the permission, or the permission for a test but not the funding. They never secured both at the same time.
Ted and his colleagues at General Atomic remained close to their counterparts at Livermore and Los Alamos, but the prospect of an actual test program raised potential conflicts with the AEC weapons labs. "The concept for charge propulsion originated in the AEC Laboratories," it was noted during an Air Force briefing on the state of the project in February 1961. "The Scientific Group at General Atomic is composed primarily of former AEC Laboratory personnel who took to General Atomic the concept and much of the technology necessary to conduct the research program. The principal investigator, Dr. Taylor, has translated the basic idea into what appears to be a workable design, aided on an informal personal contact basis by AEC scientists at the Laboratories." Now that Orion appeared to be moving ahead toward spending real money and exploding real bombs, there was some grumbling at the AEC. "At least unofficially now they have the attitude that the charge propellant work being done at General Atomic is an infringement upon AEC responsibilities and seem to resent the General Atomic work in this area. This work is being conducted by some of the best AEC scientists hired by General Atomic."[279] In July of 1961 Don Prickett met with General Alvin R. Luedecke, general manager of the Atomic Energy Commission, attempting to smooth out some of the Orion-related issues between AF§WC and the AEC. According to Prickett, "He was more concerned, however, that General Atomic be kept out of the bomb design field."[280]
Although the moratorium was still in effect, plans for testing were going ahead. "It wasn't clear during the moratorium whether we'd ever do testing again," says Harris Mayer, "but it's not that testing in itself is wrong, bad, or anything like that. There's nothing in nature that prevents you from doing very responsible tests. It's we who make the rules about this, not nature." The moratorium ended suddenly with some particularly irresponsible tests. "The Soviets burst forth with an astonishing forty-five shots in sixty-five days beginning on September 1, 1961," says John S. Foster, director of Livermore at the time. "Of these, fourteen were above a megaton, and one yielded sixty-three megatons."[281] For Livermore and Los Alamos, it was now full speed ahead. There was a big push to test anything available, especially in the Pacific, and it looked as if Orion might be able to tag along. "We went back out to the Pacific for a sequence of tests, in '61," remember Bud Pyatt. "And we had the drawings, the equipment, everything was ready, to take a model out and do a test on Orion out there. We were all getting geared up and ready to go. I even had my bathing suit packed." At the last minute, permission for the Orion test was withdrawn.
From one fiscal year and one test series to another, the Orion test proposals kept hitting political obstacles or falling through bureaucratic cracks. In 1962 it was decided to move the proposed Orion tests from the Nevada Test Site to White Sands Missile Range, at Holloman Air Force Base in New Mexico, emphasizing that Orion was a propulsion system, not a weapon system, in the hope that the approaching test-ban treaty would contain provisions for nonweapons projects to still go ahead. "Dr. Kavanu and Dr. McMillan seem to favor Holloman to lend credibility to our argument that these are propulsion tests and not weapons tests," Don Prickett reported after a trip to Washington to meet with State Department and Defense Department officials in August 1962. "Mr. Foster, Admiral Parker, and their staff seemed very receptive to our rationale as to why any weapon test moratorium agreement should, if possible, permit continuation of our testing on the ORION Project. Foster's staff stated that Foster would be talking to the President on the subject. So there is hope we may at long last get the top-level policy decision with respect to ORION and its relations to future moratorium agreements. If the United States disarmament paper reflects the stated feelings of the Disarmament Staff with respect to Project ORION we will have clearly established at the highest level of the Government that the project is propulsion and not nuclear weapons."[282]
Hopes of exempting Orion from the test ban were short-lived. "I didn't want to have a test ban as long as there was a realistic hope of going off to Mars, but by that time it was clear it wasn't worth fighting for Orion if it cost us the test ban," says Freeman. "At the end I switched from being against the test ban to being for it." Freeman spent the summer of 1963 working for the Arms Control and Disarmament Agency in Washington while the final negotiations in Moscow were under way. "We were in the old State Department building on C Street, where you still had the feeling that it belonged to a generation of gentlemen diplomats. We had big windows looking straight out on the street, so anybody who just happened to look in the window could have seen all kinds of top-secret documents lying on our desks." Freeman worked under Frank Long, chief of the Science and Technology Bureau, who went to Moscow with Averell Harriman to negotiate the treaty. Kennedy was determined to reach an agreement, but left it to Long and Harriman to decide where to draw the line.
"Although most of the questions weren't scientific, it was the scientists who did most of the work, and ran the show to a surprising extent," Freeman explains. "The main subject we were talking about that summer was Plowshare, the other peaceful use of nuclear weapons. Sometimes the United States wanted to do it and the Russians didn't. And sometimes the Russians wanted to do it and we didn't. But that particular summer the United States wanted to do it, and the Russians did not. It was the stumbling block that was making it difficult to negotiate the treaty. The Russians insisted that peaceful explosions had to be included in the ban. The United States insisted that they shouldn't. And at that point, just by accident everybody else was away at the weekend and I happened to be there. And the question came back from Harriman through Long to Washington: 'Can the United States accept giving up on peaceful explosions?' I was alone in the office. I thought very hard: 'This is the death of Orion, and is it right or is it wrong?' And I said, 'Yes, sure we can.' The treaty went through, very fast, within a matter of days."[283]
Possible
launch hazards, ranging from Class III (a single dud charge reenters
the
atmosphere and falls to Earth intact) to
a worst-case Class I (the entire ship, loaded with one thousand pulse
units,
falls into a launch-pad fire, 20,000 kg of high explosive detonates,
and a
certain amount of plutonium is dispersed).
"Technically, one could rather easily have made a test ban that would still allow Orion to develop as a non-secret project with international support and that's what we would have liked," says Freeman. "But politically it was just obviously absurd at that time." Ted, in contrast, did not concede that bomb-propelled spaceships were out. He argued that "the treaty is a web into which ORION has, circumstantially, become enmeshed, but which does not necessarily provide a permanent obstruction to its development," making the point that if the treaty was successful, it would lead to a climate of international cooperation in which a joint space project could go ahead, and if the treaty failed, then the arms race would be back with a vengeance and Orion should be pursued unilaterally by the United States.[284] "Indeed, the international situation could well deteriorate to one wherein a degree of urgency in ORION development would be necessary," he wrote.[285]
It was public antagonism to fallout, not the particular wording of the test-ban treaty, that brought Orion to a halt. All big projects kill people, but some deaths are more acceptable than others. In a large construction project, or a conventional space program, a few people will die by accident, but when they do, it is publicly evident who paid the price. Fallout diffuses too anonymously between cause and effect. Even if the risk is well below one death per mission, there will always be a thousand people to whom that slight increment in the statistics appears to be too great a price. The statistical background noise, instead of concealing the effects of a project like Orion, exaggerates them, since the tendency is to assume cause wherever there is even the remote possibility of effect. It makes little difference to what extent the fear is quantifiable or not. "Our Orion press release has been stalled by the Military Liaison Committee," complained Ted during one of the periods when funding had been secured and it looked as if things were moving ahead. "Specifically, General Loper objects to publicly describing something which generates fallout."[286] The fallout problem meant that Orion could never compete openly for political support.
The last major gasp in the life of Project Orion was a 1963-1964 design, mission, and cost study performed by General Atomic for NASA, consolidating much of the earlier work on the 4,000-ton vehicles, and extrapolating downwards to smaller, chemically boosted designs. Fallout receives two pages in the four-volume 725-page final report. Nine pages are devoted to crew compartment noise.
"Fission-product trappage in the atmosphere, from current pulse-unit designs, would result in radioactive fallout," the authors admit. "It is concluded that orbital start-up is an effective countermeasure to fallout for most missions. Each mission will have to be analyzed in more detail, however, in order to assign a quantitative figure to the penalty incurred."[287] For a typical Earth-Mars mission, there is a rough estimate of fission products produced: "Pulse units for the 10-m vehicles generate a yield of approximately 1 kiloton per pulse. Earth-departure maneuvers for typical Mars missions (several hundred to over 1,000 pulses) result in total yields of some 0.5 to 1.2 megatons, producing a quantity of fission products that must be reckoned with." By limiting Orion engines to orbital start-up and recommending that "low-level nuclear-pulse operation should be restricted to regions of magnetic latitude 40° north or south,"[288] it was claimed that "trappage by the earth's magnetic fields of the fission products that do not intercept the earth's atmosphere can be reduced to the point of being almost negligible."[289]
Freeman disagrees. "There's no way you could avoid the fallout coming down," he says. "I always felt it was more or less deliberate deception to pretend that chemical boosting could be a clean way of launching. The only advantage would have been to avoid the more immediate problems of the neighbors complaining about the noise." He criticizes the GA/NASA final report as "full of evasions and euphemisms—the kind of document that justifies the distrust of ordinary citizens against nuclear enterprises of all kinds. It never even mentions the question that any honest assessment must face: how many people would die of cancer from the Orion fallout? When I was working for the project, I spent much of my time calculating numbers of deaths. That was for me the most important question to be answered, and I tried hard to answer it honestly. No trace of my work appears in this document. Unfortunately, I do not know whether my estimates of numbers of deaths were even included in an official report. Most likely, the managers of the project made sure that my numbers never appeared in documents that outside critics might read, for the same reason that discussion of crew survival rates never appeared in any documents that we wrote at RAF Bomber Command during World War II."
Freeman's hopes for Orion had rested on the fact that "there seems to be no law of nature forbidding the construction of fission-free bombs."[290] In 1964, when the GA/NASA study was published, its authors still clung to the belief that "improvements in the design of the nuclear devices (by reducing the fraction of total yield due to fission) might achieve reduction factors of 102 to 103."[291] This belief in small, fission-free bombs has largely evaporated. It is now as remote as the 27-cents-a-gallon gasoline you could buy in La Jolla in 1959.
One exception is Ted. He remains convinced that small, clean bombs could propel Orion—but he still fears, more than ever, that such devices would be irresistible as weapons, until we outgrow the habit of war. "There are lots of different routes to that final result of a very, very clean bomb, but not pure fission," he says. "The cleaner the better, down to a point where it really doesn't matter anymore. One can argue all day about what that limit is without shedding any light until one starts talking about very specific designs, and then it does matter a whole lot. Could you make one-kiloton explosions in which the fission yield was zero, which is bad news on the proliferation front, but could turn Orion into something quite clean? How clean a bomb can you make? The answer is it can be as clean as something not radioactive at all. Would that change everything? I don't know."
Freeman thinks Ted is wrong—and Ted hopes Freeman is right.