The Ames laboratory of NACA was in California next [236] to a naval air station south of San Francisco, and since Stanley’s assignment there was not permanent, it meant that he could not bring Rachel and the boys west. They stayed at Langley and he saw them as often as he could on his trips back east to compare notes with men who were working on the reentry problem there. At Ames he occupied austere quarters, which satisfied him, for he was immersed in his challenging task.
“When you make the jump from aviation to space,” a scientist named Schumpeter said, “you have to unlearn everything you’ve been taught,” and he held up the sleek, streamlined model of a Lockheed F-104, allowing the sunlight to play upon its needle-sharp stainless-steel nose and advance probe.
“Let’s see this beauty in the air tunnel,” and he took Mott to the Ames tunnel, a vast affair, where they could watch how effectively this perfectly designed plane slipped through the air, its slim nose opening a path and its knife-sharp wings cutting through without making a disturbance.
“Perfect for its purpose,” Schumpeter explained. “I worked on the provisional models and helped them eliminate the bumps and protrusions.”
Back in his laboratory, he laid the model aside, almost contemptuously. “Not a single characteristic of that plane helps us with our problem. The F-104 flies in the air ... we have to fly through it. It makes thirteen hundred miles an hour, we make twenty-five thousand. It spreads the air aside so that it can slip through, we build atmosphere up like a wall and have to batter our way through. And it flies through cold air, whereas we fly through friction temperatures so elevated we really cannot comprehend them.”
And then, with the aid of military rockets which climbed to great heights, he demonstrated the real problem: “We’re going to take this model up to more than eighty miles. Three stages. And when we get there, we’re going to turn it around and fire two more stages to send it hurtling back through the atmosphere. Not as fast as a returning spaceship, but fast enough. And you watch what happens to that beautiful nose.”
Schumpeter led the entire team back to Wallops Island. [237] and on a starry night they fired the three-stage Honest John + Nike + Nike almost vertically into the darkness, watching its first flames burn out at 20,000 feet when its second stage took over. It soared far out of sight, reached its apex, turned over, and began its headlong rush back to Earth. As it reached Mach 17 the two remaining stages were fired, driving the model thundering back into the thin but rapidly accumulating atmosphere at the blinding speed of Mach 20.
As the scientists and engineers awaited its return, Mott speculated: “If we’d used those last two rockets to maintain our upward velocity ...” He hesitated, for he was not secure in his knowledge of rocketry and did not wish to sound stupid in the presence of the team with which he would be working for a long time, but his proposal was so daring that he felt compelled to explore it.
A young engineer named Levi Letterkill anticipated him: “Yes, if we’d maintained the upward thrust and goosed it with two additional rockets, we could have built up our speed to about eighteen thousand miles an hour, enough to throw us into low earth orbit.” When Mott hesitated about making any response, the young man added tentatively, “I’ve been told that if you can get up to twenty-five thousand miles an hour, you can escape low earth orbit and go into orbit around the Sun.”
“Could our rockets tonight have produced such a speed?” Mott asked.
Letterkill stood silent, making calculations. “Yes. We could have gone into orbit this night ... or tomorrow night.” He hesitated, for as Mott was to learn, he was a cautious man working in unknowns where a miscalculation might prove disastrous. “I think we might have wanted slightly more powerful rockets in the last two stages.”
“Are such rockets available?” Mott asked, and another member of the team answered, “With big enough rockets, anything is possible.” Mott, remembering a dozen failures of the A-4s in New Mexico, concluded that it was going to be just a little more difficult than these men were saying.
When his team assembled all evidence on the vanished rocket and its payload-telemetric reports, optical observations, multiband radar records-Mott was startled by [238] the conclusions a Department of Defense expert offered: “Nine inches of the hardest metal we can fabricate burned away as if it was a dry board.”
Several experimenters asked for an elucidation, and he said, “The thin leading point of the metal encounters molecules of atmosphere, battles against them, builds up a super heat, finds oxygen in the atmosphere and burns like chaff. When the point is gone, the next sixteenth of an inch faces the tremendous heat, and it burns, exposing the next point. And then the whole thing goes, one small point after another.”
“And remember,” Schumpeter said ominously, “This model had to penetrate only part of the atmosphere and at only part of the speed our returning vehicle will have.”
A heat engineer said, “If our model had encountered the true conditions, its entire substance would have been consumed.” In the night air a plane, its lights flashing, headed back to Patuxent River across the bay, and the men watched its progress. “A plane like that,” the heat engineer said. “could not possibly get back through the atmosphere. Every vestige except maybe the castings of the engine mounts would burn up.”
Back in California, the team went to work, always with the model of the burned F-104 before it. “We want something as different from that as possible,” Schumpeter reminded them, and the search centered upon that requirement.
The heat engineer established the three basic alternatives and disposed of two: “We can come in with a pointed nose and burn up. Or we can use a heat-sink principle, which is entirely practical, except for one slight handicap.”
When members of the team wanted to know what heat sink was, he explained easily: “We construct a metal an alloy of the most specific components featuring titanium, and we cover the entire leading edge of the vehicle with this alloy. When it comes thundering back through the wall of the atmosphere, the alloy accumulates the heat and doesn’t burn at all. It simply absorbs it ... dissipates it.
“Even if the nose is pointed?” Mott asked.
“No, no!” The engineer laughed. “You make the poiw sharp enough, the heat will burn anything, anything at [239] all. So we’ve got to be talking about a blunter surface. But with a blunt surface, the heat sink will work.”
“What’s the drawback?” someone asked.
“Weight,” and he put on the blackboard some figures. If we cover the leading edges of a blunt-nosed airplane with enough alloy to heat-sink the temperatures, the plane would weigh something like three hundred tons and would require fifteen or twenty of the engines we now use, which would in turn require fifteen or twenty times the amount of fuel. A heat sink is a marvelous idea ... for a tank, not for an airplane.”
“And the practical alternative?” Schumpeter asked.
“Ablation,” the engineer replied, and for the first time Stanley Mott heard the miraculous word which would dominate his life for nearly two years. From his study of Latin at the high school in Newton, Massachusetts, he knew the word ablative, for it denoted a grammatical form much loved by Julius Caesar, a no-nonsense engineer himself. “The ablative absolute,” his Latin teacher had explained, “is used by men of action who don’t want to waste words: Ponte factō Caesar transit. The bridge built, Caesar crossed it. Consider how effective this is. No bothering ,with who built the bridge or at what cost. The bridge was built, as a bridge should be, and Caesar crossed it.”
For some weeks Mott had concentrated on this amiable construction, using it correctly and effectively: “Equation solved, I turned the page.” He did not crybaby about the difficulty of the chemistry equation; he solved it and got on with the job. In fact, the ablative absolute could be said to have become Mott’s guiding principle in his education, and he was delighted to learn from a footnote in his Latin grammar that the ablative was one of the earliest cases in human language. It died out
in Greek and the Teutonic tongues and did not even have a name until Caesar personally christened it. “My case and Caesar’s,” Mott said whenever he came upon a felicitous example.
But now he could not envisage any relationship between his grammatical ablative and the engineering one. “An ablative material is one that merely wears away. It doesn’t actually burn, although it looks as if it had charred. It boils away, or evaporates, one tiny bit after another, in the super heat. And it does so with astonishing slowness. [240] Water, wind, fire, even heat can’t destroy it in a hurry But almost anything can wear it away ... very slowly.”
The word in its two meanings was even pronounced differently: ab’lative in grammar, a blayt’uv in engineering. But Mott paid attention when the heat engineer demonstrated what might be achieved with a good ablative material: “I have here a block of reasonably good material, two inches thick. With this blowtorch I’m going to produce extreme heat on this face. You’ll see the material become white-hot, evaporate, and leave a residue which the air from this fan will blow away. But I’ll hold the back of the thin block in my left hand, which will not even feel the heat.”
And he did exactly that. The blowtorch hissed its throbbing flame directly at the block of material, which behaved as the engineer had predicted: it charred but it did not burst into flame, and when the discolored material blew away, what lay underneath was not even discolored. Nor did the tremendous heat penetrate the block; it was carried away by the material as it was ablated.
When he completed his demonstration the engineer asked Mott to hold the block, and even at the point of maximum heat, Stanley could feel nothing, so effective was the ablation. “What is the material?” Mott asked.
“Now here we have hope,” the engineer said. “This isn’t even a good material. It would last up there about one second. Char completely away. But I’m convinced that we can construct a material to our specifications-and it won’t be just good, it’ll be perfect. That’s our job.”
For six months Mott worked with the Department of Defense reentry team and with experts from private business on the bizarre task of creating a new material that would fill a precise need in the space program, and after only a brief exploration of the problem and an analysis of what the various companies could provide, it became apparent that the contract for constructing the new material to specifications would have to be awarded to Allied Aviation, because their people had already begun investigating this problem. They had not by any means solved it, but at least they knew where the difficulties were going to lie, and it was in this way that Mott found himself once more working with General Funkhauser.
The man was amazing. Starting with a knowledge of [241] ablation even more defective than Mott’s, he was assigned by his company to supervise the project because the American managers had learned that this remarkable German could organize an effective team to attack any problem in either aviation or space. He had a general knowledge of everything and a specific skill in cajoling experts to work together, and when it came to serving as an interface-one of the bright new words-between private industry and government, he was a genius. “After all,” he told Senator Glancey’s committee in secret session, “if I could work with a madman like Hitler and keep my head, I can certainly work with reasonable men like General John Medaris.”
The new material would be constructed of three components: a basic substance which burned slowly even under ordinary conditions, a fiber of some kind to provide tough resilience, and a binder. In the old days it would have been asbestos, flax-cord and glue, which together could have formed a fine sturdy material that would not burn in an ordinary gas flame, but now even better materials were required.
Each of the three components had to be invented separately, and the experts at Allied Aviation proposed some eighty different substances, each effective by itself but not particularly useful in combination. “Two of them are always right,” General Funkhauser observed, “but the third intrudes like an unwanted guest at a honeymoon.”
The search went on interminably, and so much superheated gas was wasted on burning away materials that were supposed not to burn that Mott began to wonder if the proper combination would ever be found.
While these studies were under way, Schumpeter was engaged in devising the proper profile for the space vehicle itself, not the giant structure that would sit atop Von Braun’s rocket when it went up, but the small capsule in which the passenger would direct the flight, and the more he worked, with that shining F-104 on his desk, the bigger and bolder the ablative surface became, until one day in desperation he sketched on his blackboard a monstrous affair which looked not at all like an airplane but like a giant toadstool.
“It still has a protruding stem,” one of the team pointed out. “That’ll burn away.”
[242] “We’ll bring it in ass-backwards,” Schumpeter said, and for some minutes the team studied this remarkable proposal, which seemed to contradict everything known about flight, and gradually they began to see that what Schumpeter was proposing was really the only way to solve this difficult problem: if a pointed nose burned away, bring the damned thing home like the side of a barn, smear it with a foot of ablative material, and come bursting right down through the atmosphere with sparks flying as the material carried the heat away.
The team flew back to Wallops Island, where Rachel and the boys sat in their car off the base to watch strange blunt objects being thrown into the upper atmosphere by their father, who told them, after months of testing, “We’re on the verge of something great. The others have solved their part of the problem. I haven’t.”
When Schumpeter’s revolutionary structure proved that it could manipulate the upper atmosphere, the pressure on Mott and General Funkhauser to provide the proper protective material increased, and in the eighth month of their experiments they produced a masterful new material composed of silica-based granules in place of asbestos, a newly invented fabric instead of familiar ropes, and an epoxy in place of glue.
Schumpeter summarized the tests: “This is a wonderful material. Perfect in every requirement, except one. It weighs five times too much per cubic inch.” And when he placed his calculations on the board they supported his objection: “You’ve given me an excellent material for protecting Mack trucks on their way through Arizona. Now let’s find something for a spaceship.” So Mott’s team went back to work.
In many ways Mott epitomized his nation and his culture. Despite the fact that he had ignored the pioneering work of Robert Goddard, he had been forced by German successes in World War II to take rocketry seriously, and this had led him into making advanced studies of the upper atmosphere, and once he comprehended the nature of that mystical ocean he was driven to master it with rocket vehicles and imaginative instruments to measure the heating rate which would have to be neutralized before man could venture upward through the atmosphere, break [243] loose from it, and then return through its fiery heat. His two most recent publications indicated the intensity of his study:
Schumpeter, Karl and Mott, Stanley: Controlled Rocket Experiments, Three Stages Up, Two Stages Down, Testing the Ablative Characteristics of Eight Alternative Configurations. 1957.
Mott, Stanley: Nineteen Ablative Coefficients of Seventeen Fabricated Materials. 1958. (Secret)
His speculation about the future had started with his innocent question on the beach at Wallops: “If we’d used those last two rockets to maintain our upward velocity ...” He had known the answer. before he framed it; if his studies helped men to penetrate the atmosphere and return safely through it, the next step must be to shoot them into brief orbit, and after that to send them on sustained orbits, and from that platform to challenge the Moon, then Mars, then Jupiter, then the Galaxy, and on to the very edges of the universe.
How simple his first steps along this path had been: algebra in grammar school, trigonometry in high school, calculus in college, and now the majestic problem: If we should ever want to send a rocket to the Moon, what
trajectory would we use? The questions, the possibilities were endless, and although he could not yet chart specific solutions, he saw with great clarity that the proper approach was to apply to each chance assignment his complete brain power, trusting that other men like himself were applying their power to their contributory tasks.
He worked nine weeks, incessantly, his glasses blurring from perspiration and from the fumes of his testing, and in the end he helped produce a master ablative material, light as soft wood, sturdy as hardened steel, quick to evaporate and carry away heat, but stubbornly averse to burning. When Schumpeter put these figures on his board he cried, “We have it!” and one more step in the infinite process of commanding space was completed.
Funds for the kind of experimentation Stanley Mott was engaged in were provided by a grudging Congress, which often masked the purpose of the work by allocating the money not to NACA but to the military, for Schumpeter’s [244] studies of reentry applied equally to a ballistic missile of the Army, a rocket of the Navy, and a putative spacecraft of NACA.
NACA now had a staff of about 7,000, and with branch centers like Ames and Wallops Island, it controlled research facilities worth more than $400,000,000, so funding became a major problem. Fortunately, Lyndon Johnson, the power in the Senate, supported the aviation program and its ramifications in space, but he had to assign the difficult task of shepherding the necessary bills through Congress to the two Western senators, Glancey and Grant, and it was for this reason that Senator Grant saw less and less of his fragile wife, Elinor, who often stayed behind in Clay when he attended the sessions in Washington. As for visiting the NACA bases, which her husband had to do with increasing frequency, this she refused to do, whether she was in Clay or in Washington, yet she continued to protest whenever she saw a photograph or news story which indicated that Mrs. Pope had accompanied the committee.
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