Rocket Girl

by George D. Morgan

  An hour later, Tom returned with two young men in tow. One had pale skin and wore the de rigueur engineer's crew cut. The other was a Japanese man who looked several years older.

  “Mary, I'd like you to meet Bill Webber and Toru Shimizu. Gentlemen, North American's finest propellant analyst, Mary Morgan.”

  The three shook hands. Mary noticed their badges looked brand-new. Had they been recruited from another division or another department of the company?

  Tom pointed to two adjoining desks. “Those will be yours. I leave you in capable hands.”

  The two young men looked lost. To Mary, it seemed that they had the air of a couple of high-school freshmen on the first day of class.

  “Why don't you two pull your chairs over and we'll have a meeting.”

  As they did that, Mary asked, “So which department did they move you over from?”

  Bill and Toru looked at each other, clearly unsure of what to say. Bill spoke first.

  “Well, I just got my master's degree in chemical engineering from Caltech. I was at a recruiting fair and North American hired me.”

  Mary was surprised. “You're right out of school?”

  Bill nodded. Mary turned to Toru, hoping for more.

  “And what about you?”

  “I just received my MS in chemical engineering from UCLA.”

  There was a long pause as everyone worried over a different problem, then Toru added:

  “I would have graduated sooner, but I spent four years in Manzanar.”

  “Manzanar. You were in a Japanese internment camp.”

  Toru nodded. Mary rubbed her temples—a headache was coming on.

  “So for my assistants I have been given a couple of virgin newbies.”

  At first Mary felt indignant about being given two assistants with no rocket or propellant experience whatsoever. That lasted about five seconds, at which point she changed her mind and decided it would be advantageous to work with fresh meat—a couple of guys who carried none of the baggage of preconceived notions of what was possible. For this project she would need open minds. Besides, even though she had far more experience, these two young men were far better educated. She would find their strengths and put them to good use.

  Mary handed each man a file full of graph paper, on which was a myriad of formulas and math calculations.

  “In the propellant-design field we work a great deal with simultaneous nonlinear equations. Have either of you ever done any of those?”

  Toru spoke first. “Well, there's no straightforward method for solving simultaneous nonlinear equations.”

  “That's correct,” said Mary.

  Bill asked, “So what's your approach?”

  Mary smiled. They may have been new recruits, but she could tell they had potential.

  “We do a lot of guessing. We make an intelligent guess at what a particular combustion temperature will be based on past experience and measurements, then calculate what the composition would be without the dissociation. Then we calculate how much dissociated species would be present by repeated approximations. Once that's done, we calculate the enthalpy balance to determine whether our temperature guess was too high or too low. Then…”

  “Then you make a better guess of the temperature and continue to repeat the process until everything balances out,” said Bill.

  “Exactly.”

  Toru raised his hand. “But all that work isn't going to yield much data.”

  “Correct,” said Mary. “The bad news is that ‘all that work,’ as you say, only yields a single data point on a very long curve for a single propellant combination using a single mixture ratio at a single chamber pressure.”

  “The permutations must be endless,” said Toru.

  Mary nodded. “They're infinite. And we don't have time for infinite.”

  “So what you're saying,” said Bill, “is that our country's success or failure in getting into space is highly dependent on our ability to make good guesses.”

  “That's pretty much it.” Mary pulled a Kent from its package and lit it with a match. “The good news is that the Russians have the very same problem.”

  Bill shook his head. “You could get a damn monkey to make a halfway-decent guess.”

  Mary took a long drag on the cigarette and blew the smoke out long and slow.

  “Welcome to the monkey cage.”

  “There is no such thing as consensus science. If it's consensus, it isn't science. If it's science, it isn't consensus.”

  —MICHAEL CRICHTON

  The next morning as Mary was making breakfast, she spread some honey on a piece of toast. The image of the golden honey triggered a long-ago memory, a flashback: Mrs. Bowman's chemistry experiment in the one-room schoolhouse in Ray. Water, vegetable oil, honey. It was an experiment about buoyancy and…

  “Density! How could I forget density?”

  She tore off a section of the morning newspaper and wrote “HIGH DENSITY” in large block letters, then placed the note in her purse. The sizes of the Redstone propellant tanks were fixed, so whatever propellants they used would have to be dense enough to fit. Therefore, density of the final propellant was crucial.

  An hour later, Mary was showing her badge to the security guard at North American, passing through the steel door, and negotiating the desk maze to her station. She had arrived an hour early so she could get a few things done before Bill and Toru showed up. But when she reached her desk, she was surprised to find both men already there. On all three desks were mounted large cardboard posters with fuel and oxidizer names and performance data.

  “How long have you two been here?”

  “A couple hours.”

  “We wanted to get a head start.”

  “We put together some potential propellant combinations.”

  “If you have a moment we've prepared a little presentation.”

  “You guys came in early to make a prospect list. You've impressed me.”

  They smiled, proud of themselves—until Mary shook her head.

  “You've got all sorts of oxidizers on here. I told you: we're focusing on the fuel side of the system.” She grabbed a black marker and pulled off its cap.

  “I'll save you boys some work.”

  Using the marker, she began crossing chemicals off the list.

  “Let's see, you've got alcohol with fluorine. I know what you're thinking; the Redstone is already alcohol-compliant, so why not lean toward it. But the oxidizer side of the system will not withstand even a slight amount of fluorine. So we'll cross out fluorine and all its derivatives like FLOX; already considered and dismissed. What else ya got here? Hydrazine—no. Monomethyl hydrazine—no. Aniline with ozone; that would give us a good isp but ozone is too unstable—that's a no. Propane with LOX—no. JP-4 with LOX—wrong mixture ratio. Same problem with all the kerosene pairs you have here—no, no, no. Hydroxyl-terminated polybutadiene—my God, how did you even know about that one? Mixed with fluorine—already a no. Matched with nitrous oxide—isp will be too low. Ethylene with LOX—not bad, we'll hold on to that one. Ammonia with LOX—no. B2H6 with hydrazine as an oxidizer? Innovative, but hydrazine is out on both sides. Aniline with RFNA—no. Hydrogen…hydrogen!? What have you two been drinking? Methane with LOX—that might take us somewhere. Lithium with fluorine!? My god, you boys are dangerous. RP-1 with nitrous oxide—no. Turpentine with nitric acid—no. And finally, nitrogen tetroxide and pentaborane with LOX—no and no.”

  The posters were now covered in black ink X's, with every chemical formula combination crossed out save for two. Bill and Toru looked disappointed.

  “We worked hard on that.”

  “Why were you so quick to dismiss hydrogen? The specific impulse with oxygen is terrific.”

  “And what's so bad about hydrazine? My reference book says…”

  “Your reference book has never built a rocket. Sit down.”

  Both men sat down.

  “First of all, let's get hydrogen out of the way.
We absolutely cannot use it. Anyone want to guess why?”

  Bill spoke first. “It's cryogenic.”

  “So I take it the fuel side probably would not accept a cryogenic liquid,” said Toru.

  “You're both right, and you're both wrong.”

  Mary pulled the “properties and characteristics” list from beneath the chemical reference book, added “density” at the bottom, then held it out so both men could read it.

  “This is the list of properties and characteristics our new fuel must have. What's the first item on the list?”

  “Commercially Available.”

  Mary taped the list to a file cabinet. “Let's say we got past the cryogenic problem and found a way to use hydrogen. Where would we buy it?”

  Both men looked at each other, hoping the other would have the answer.

  “Well, I'm sure there must be some place…”

  “No. Liquid hydrogen is not available in large quantities in the United States, or in any country in the world we can import from. It's not commercially available anywhere. Someday it probably will be, but if you need more than a few liters right now, you're out of luck.”

  She let that sink in, then continued.

  “Now let's move on to your other question: What's so bad about hydrazine? The A-7 engine is regeneratively cooled. Do you boys know what that means?”

  “Not exactly.”

  “It means the fuel is first circulated around the rocket engine before being pumped into the injector and burned. This helps keep the rocket engine at a stable temperature. Or to put it another way, it keeps the engine from overheating and blowing up.”

  “In other words, same principle as water cooling in a piston engine.”

  “Exactly, except cars don't run on water. Here we're using the actual fuel to do the cooling.”

  “Right.”

  “So one of the properties and characteristics of hydrazine is that it is a very poor coolant. It does not have good heat-transfer qualities.”

  “So if we used it the engine might overheat.”

  “I'm afraid so. We tried using it in the NAVAHO engine, with negative results.”

  “Define ‘negative.’”

  “It blew up.”

  “Ah.”

  Mary snatched the list from the file cabinet and handed it to Toru. I want you guys to make twenty copies of this list and study it carefully. After lunch we'll do what you tried so nobly to do this morning: we will make our prospect list.

  “Why do we need twenty copies?”

  “I'm going to have you pass the list around to some of the other engineers and supervisors to make sure I haven't left anything off.” Mary handed them each a list of the individuals she wanted the properties and characteristics distributed to.

  “Mrs. Morgan,” said Toru. “Do we really have to get other engineers involved? Bill and me, we talked it over and we're pretty confident the three of us can achieve the contract requirements.”

  Mary looked at Bill, who seemed to agree.

  “Look, guys, when you're in school it's all lonely work. You study alone, you do your homework alone, and when the exam comes around you have to complete it alone. But once you're in the workforce the rules change one-eighty. Now we work together as a team, and everyone in this building is part of our team, even if they aren't specifically assigned to us—understand? Now get that list copied off, and make sure everyone on the second list gets a copy. One more thing.”

  She handed them a book. It was titled Rocket Propulsion Elements.

  “This is an advance copy of a book that's about to be published. It was written by one of our engineers, George Sutton. Go to the chapter on specific impulse. Don't come back here till you understand what it is and how to calculate it. Now scoot!”

  As Bill and Toru headed off for the mimeograph station, Mary took the stairs to Tom Meyers's office.

  At about the same moment Mary was climbing the stairs to have a word with her boss, Wernher von Braun, his wife, and 102 fellow German scientists and their families were being sworn in as naturalized US citizens. As part of the ceremony, von Braun was invited to give a speech.

  “This is the happiest and most significant day in my life,” he said. “I must say we all became American citizens in our hearts long ago. I have never regretted my decision to come to this country.”1

  The ceremony was held at Huntsville High School's auditorium, and there was not an empty seat to be had.

  Afterward, von Braun jumped right back into his daily grind: crisscrossing the country preaching the gospel of space travel, making speeches, appearing as a guest on the Walt Disney TV show, and working with other engineers to resolve all the technical barriers to putting a satellite into orbit.

  Of those technical barriers, none loomed as large or as urgent as the main-stage propellant problem. In fact, the propellant problem had become the only problem—the bottleneck that was keeping him and his rocket from reaching orbital-space glory. For this reason, von Braun decided to travel to California and pay a visit to the executives at North American Aviation.

  Josef Stalin had been dead for a year. His successor, Nikita Khrushchev, was still working on solidifying his place in the Soviet government. Unable to afford an arms race with the United States, Khrushchev was gambling that Korolev's missile program would make moot America's dominance in bombers and other heavy aircraft. Ironically, history would show that Russia's inability to compete with the United States in financial resources would cause them to stumble into a much superior technology. Korolev would not disappoint his premier—Khrushchev's gamble would pay off in ways more spectacular than anyone could imagine.2

  As Wernher von Braun was flying to California to have an urgent meeting with the executives at North American Aviation, Nikita Khrushchev and a small group of Soviet leaders were traveling to Tyuratam to meet with Chief Designer. They wanted to see for themselves what their rubles were buying at his rocket factory.

  When Bill and Toru returned, Mary was not at her desk. The first thing they noticed was that a large chalkboard on wheels had been brought in and was parked in front of Toru's desk. On it were chalked four numbers: 305, 1.75, 155, and 0.8580. The second thing they noticed was that someone had crossed out the last two propellant combinations on their posters.

  “Do you feel as unappreciated as I do?”

  “Yes.”

  At that moment, Mary returned, carrying a box full of files.

  “You decided you didn't like any of our choices.”

  “I like all of them, but Mr. 305 and Mrs. 1.75 dislike them immensely.” Mary set the box down on her desk, then stood next to the chalkboard. “So are you both comfortable with specific impulse?”

  Both men nodded. “We get it.”

  “Good. So here's our job: Von Braun needs a propellant combination that will yield a specific impulse of at least 305 seconds. The Redstone hardware is designed to mix the propellants in a ratio of 1.75, meaning for every 1.75 pounds of oxidizer that flows into the combustion chamber, one pound of fuel flows in to mix with it. Whatever propellant combination we end up with, it must yield an isp of at least 305 when mixed at a 1.75 ratio. Understand?”

  Both men nodded.

  “Which is why I crossed out all of your suggestions. None of them will give us an isp of 305 if mixed at a 1.75 ratio. They all have the ability to give us impressive specific impulse results, but at vastly different mixture ratios.”

  Toru raised his hand. “What is the third number?”

  “The third number is burn time. The Redstone was originally designed with a first-stage burn time of 110 seconds. But that was in its original genesis as an ICBM. To get into orbit, von Braun has calculated that he will need to extend the first-stage burn to 155 seconds.”

  “Why is that important to us?”

  “Good question, which brings us to the final number: 0.858. The units here are grams per cubic centimeter.”

  “Density?”

  “Exactly. Whatever fu
el we decide to replace the alcohol with must have a density of at least 0.858. Otherwise we won't be able to put enough into the tank for a 155-second burn.”

  “You're saying it has to be even denser than the alcohol, which is around 0.80.”

  “0.7893 to be exact.”

  “So where do we start?”

  “At the beginning. We need to make a prospect list—a list of all chemicals that yield an isp greater than 305 when mixed with liquid oxygen. It will be a process of elimination. We will strike fuels from the list one by one until we find the fuel that conforms to all four of those numbers.

  Both men were quiet for a moment, then Bill spoke.

  “Well, uh, when Toru and I were handing that list out, like you asked us, we ran into Tom Meyers.”

  “And John Tormey,” Toru added.

  “I guess Tormey is Tom's supervisor, right?”

  “Yes,” said Mary. “So?”

  “Well, they said we're supposed to be looking for a better oxidizer, not a better fuel.”

  “What did you tell them?”

  Toru shifted in his seat. “We didn't really tell them anything.”

  “We weren't sure what to say. But if two managers, both with lots of authority and very expensive suits, tell us to look for alternative oxidizers, rather than fuels, shouldn't we be doing that?”

  “No,” said Mary. “Now let's get to work.”

  One day I get a call from Delores Bing, a member of the performing-arts faculty at Caltech. She is calling with good news: the Caltech Theater Department has hired a replacement for the recently retired Shirley Marneus. Caltech once again has a theatre arts director. She tells me the reason the hiring process took several months was that they went through a large number of prospective directors.

  “We're still committed to doing your play,” she says. “And we think you'll like who we've chosen to do it. He has a lot of film and TV credits.”