NASAs Saturn V Rocket, the Moon Rock Box and the Woman Who Made Them Work Properly – Scientific American

What did Yvonne Y. Clark, or Y.Y., actually do as a mechanical engineer? This episode is about the work itselfspecifically, the work Y.Y. did at NASA on the Saturn V rocketandthe design ofthe moon rock box for transporting lunar samples back to Earth. And we take a deep dive into the history of the American space program, the mechanics of a rocketand how Y.Y. brought her troubleshooters mind to a problem that was plaguing some of the countrys top scientists.

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EPISODE TRANSCRIPT

NASA, Rocket Engines, and the Moon Rock Box

ARCHIVAL TAPE: 1957, year of space and Sputnik dogs Laika, first space traveler, was ready for the takeoff

KATIE HAFNER: As the Cold War heated up, the United States and the Soviet Union were in a race to achieve breakthroughs in space exploration.

ARCHIVAL TAPE: The United States space program advanced as the Saturn V rocket was rolled out to

KATIE HAFNER: The U.S. set its sights on sending humans to the moon

JOHN F. KENNEDY: We choose to go to the moon. We choose to go to the moon

KATIE HAFNER: Project Apollo was a completely unprecedented undertaking, and to make it happen, NASA hired outside contractors.

YVONNE CLARK: My assignment was to, um, help design the box that brings the samples the rocks back from the moon.

KATIE HAFNER: One of those contractors was Yvonne Young Clark.

KATIE HAFNER: Im Katie Hafner

CAROL SUTTON LEWIS: And Im Carol Sutton Lewis

KATIE HAFNER: And this is Lost Women of Science. In this episode, we are diving into the work what Yvonne Young Clark

CAROL SUTTON LEWIS: known as YY

KATIE HAFNER: known as YY actually did as a mechanical engineer. Well look at two designs that YY worked on while she was at NASA: the F-1 engine of the Saturn V rocket thats the rocket that got us to the moon and the Moon Rock Box, which was used to collect lunar samples.

CAROL SUTTON LEWIS: We started looking into YYs work at NASA to learn about what exactly she did there.

But investigating her time at NASA also opened our eyes to the important and complicated history of the space program

KATIE HAFNER: So before we can get into YY's work with rocketry and materials science, we want to take you back to the early days of NASA

ARCHIVAL TAPE: Huntsville, Alabama, founded in 18 hundred and five. Just a few years ago, Huntsville was a quiet town. But today, the sound of industry and progress in this community is the bellow of a rocket motor.

CAROL SUTTON LEWIS: The U.S. army had a post just outside Huntsville, where civilians and army personnel worked on missiles, munitions and rocket design.

ARCHIVAL TAPE: Quiet no longer, Huntsville now is rocket city USA.

CAROL SUTTON LEWIS: Huntsville became rocket city in a pretty surprising way

TEASEL MUIR-HARMONY: Huntsville, Alabama, it's worth noting, is this interesting case...

KATIE HAFNER: Dr. Teasel Muir-Harmony is curator of the Apollo Collection at the Smithsonians National Air and Space Museum. We talked to her about NASAs history.

TEASEL MUIR-HARMONY: The big figure head there is Wernher Von Braun a former Nazi SS officer. And he came to Huntsville with a bunch of German Nazi engineers.

KATIE HAFNER: You heard that right: Nazi engineers. As World War II ended and the Cold War began, the United States started bringing in German scientists to work for the government as part of a top-secret intelligence program called Operation Paperclip. The U.S. wanted to capitalize on Nazi weapons technology and keep these scientists out of the hands of the Soviet Union. Wernher von Braun, whose expertise was rockets, was one of the first to arrive, in September, 1945. Ultimately, more than 1,600 German scientists came to the U.S.

TEASEL MUIR-HARMONY: And so Huntsville, Alabama is hugely influenced culturally by all these ex-Nazi engineers who worked on the V2 rocket program in Germany during World War II.

KATIE HAFNER: During the war, it was Germany that had the most advanced rocket technology that countrys V2 rocket was the worlds first long-range guided ballistic missile. The construction was overwhelmingly carried out using forced labor, by concentration camp prisoners. In the U.S., von Braun and his team started building on the design for the V2, expanding its range even farther

This work was the basis for the U.S. space program.

TEASEL MUIR-HARMONY: The space age really began in 1957 with the launch of the first artificial satellite, uh, by the Soviet Union in October of 1957. And thats Sputnik.

KATIE HAFNER: Just a decade or so earlier, the US and the USSR had been allies during the second world war. But rising tensions led to the Cold War. The successful launch of Sputnik meant that now, it was the Soviets that had more advanced technology than the Americans.

In 1958, NASA the National Aeronautics and Space Administration was created.

ARCHIVAL TAPE (JOHN F. KENNEDY): I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth.

KATIE HAFNER: On May 25th, 1961, President John F. Kennedy presented Project Apollo and the objective of a lunar landing with a human crew to a joint session of Congress and the public.

TEASEL MUIR-HARMONY: It was an extraordinarily bold and ambitious goal. When he did that, the United States only had 15 minutes of human space flight experience.

KATIE HAFNER: Astronaut Alan Shepard had successfully gone to space and back but he wasnt the first human to do that. The USSR had sent Yuri Gagarin to space a month earlier. So for Kennedy, Project Apollo wasnt just about going to space

TEASEL MUIR-HARMONY: Kennedy wasn't a space enthusiast. He didn't support Apollo because he dreamed of space flight. But he saw sort of the, the important political potential.

KATIE HAFNER: In her book, Operation Moonglow, Teasel explains the political history of Project Apollo. Landing on the moon could help shore up U.S. international influence.

TEASEL MUIR-HARMONY: Kennedy thought that this was the type of program that could win the hearts and minds of the world public, um, which he saw was going to be critical to U.S. national strength in that very particular Cold War moment.

KATIE HAFNER: And part of that strategy, according to Teasel, included using the space program to expand civil rights domestically.

TEASEL MUIR-HARMONY: Also there is a sort of an important thread, this idea that the space program could help advance U.S. civil rights and that it could be a means for helping to integrate the South, um, and providing job opportunities for African Americans.

KATIE HAFNER: For context, just days before Apollo was announced, the Freedom Riders, a group of demonstrators protesting segregation in the South, were attacked by a white mob in Montgomery, Alabama.

Project Apollo offered an opportunity to both present a different image of the United States and to actively promote integration in the South.

TEASEL MUIR-HARMONY: And so there were particular recruitment efforts by NASA to help recruit African American engineers.

KATIE HAFNER: But Teasel Muir-Harmony says the numbers werent huge.

TEASEL MUIR-HARMONY: For African Americans in the Apollo program, I think it was 1.5 to three percent of the NASA workforce. And women were two to three. So you can imagine how small the numbers are for African American women.

CAROL SUTTON LEWIS: Its pretty clear YY was one of the very, very few.

KATIE HAFNER: But that doesnt mean she was alone. Multiple efforts are underway now to highlight the work of the diverse scientists, engineers, mathematicians and technicians who contributed to the space program. Some of their stories have been told in the book and the movie Hidden Figures.

CAROL SUTTON LEWIS: And some of them, like YYs, are only now being told

At this point, YY was teaching mechanical engineering at Tennessee State University. That meant she had summer breaks, and she was available to do other work

In 1962, YY headed to Huntsville to start a job at Redstone Arsenal, a garrison for various government departments. Redstone was where the army was doing its rocket research.

YVONNE CLARK: Oh, wow. That was a rough one that summer.

CAROL SUTTON LEWIS: She worked as a mechanical engineer in the Dynamic Analysis Branch.

YVONNE CLARK: They had me doing six degrees of freedom.

CAROL SUTTON LEWIS: We talked about this in the last episode. The six degrees are all the ways an object can move through space. YY was now applying that principle to missiles and rockets, calculating their potential movements.

YVONNE CLARK: And that was my first encounter with the government at that level.

CAROL SUTTON LEWIS: It also meant that YY had broken her third and last never: never work for the government.

But breaking that last never opened up more opportunities.

The next summer, in 1963, YY was hired at the recently-established George C. Marshall Space Flight Center, also based near Huntsville. Shed already been working on missiles and rockets in her previous posting, so she was in her element. And unsurprisingly, she was asked to troubleshoot

YVONNE CLARK: We were having hotspots. So my assignment was to find out what causes the hotspots.

CAROL SUTTON LEWIS: A hot spot is exactly what it sounds like: a section of a rocket or engine that gets too hot. The rocket YY was working on was the Saturn V, still the largest rocket ever built.

But what exactly did work on these hot spots entail? And how did the hot spot problem fit into the bigger picture of Project Apollo?

COLLEEN ANDERSON: I was trying to figure out exactly the work that she did with NASA. I was in contact with the NASA archives down in Huntsville, where she worked on the Saturn V rocket

KATIE HAFNER: Dr. Colleen Anderson is a colleague of Teasel Muir-Harmonys. Shes the curator for rockets and missiles after 1945 at the National Air and Space Museum.

COLLEEN ANDERSON: and they don't have any documentation saved about the work that she, she did with them.

KATIE HAFNER: Which means weve had to piece a lot of this together from YYs own recollections. As Colleen tells us

COLLEEN ANDERSON: I think there's a lot that was written that was quite good about, you know, the technical history of what things are and how they were built, but who built them, why they built them, uh, has kind of been overlooked.

KATIE HAFNER: Its also important to remember that YY was one contractor among many. So, to figure out what she was doing, weve had to put it into context

COLLEEN ANDERSON: So it seems like given the timing of when, uh, she was at Huntsville working on this problem on the hotspots, this is the same time that engineers and I think it's a team of many, many, engineers, were trying to figure out the problem of the instability, the combustion instability.

KATIE HAFNER: Given that YY joined the project in 1963, its likely that her hot spot assignment was one small part of a much bigger problem. And that big problem was combustion instability.

Rockets and missiles, for that matter work by using combustion reactions.

The fuel, which could be kerosene or hydrogen or some other hydrocarbon, is ignited in the chamber of the engine. It reacts with oxygen and burns. Thats what a combustion reaction is.

But combustion alone wouldnt get your rocket to space, or even very far off the ground. The real power comes from the byproduct of combustion the super hot gases it creates and how those gases are harnessed by the rockets design to propel it forward.

When combustion happens in a small space, like the chamber of a rocket engine, the hot gas expands rapidly. This builds up a whole lot of pressure that has to go somewhere. In a rocket, its forced out through a small nozzle. This is what produces thrust, the force that propels the rocket forward.

The problem NASA was having with the Saturn V was that the combustion reaction in the engine was basically getting out of hand.

COLLEEN ANDERSON: When the kerosene and the liquid oxygen were reacting in the main chamber, it was creating these pressure waves.

KATIE HAFNER: When scientists use combustion to power a rocket, they need to produce heat for power. But NASA was now facing a problem where the fuel was getting so hot and producing so much pressure, it was actually creating pressure changes that caused violent vibrations

COLLEEN ANDERSON: These pressure changes would periodically move through the engine.

KATIE HAFNER: In smaller rockets, this wouldnt have been that big of an issue the pressure waves couldnt build up, or the engine ran out of fuel before any real damage could occur. But the scale in this project was unprecedented. The Saturn V was a huge rocket. And it used some incredibly powerful engines

COLLEEN ANDERSON: One of the engines used on the Saturn I is called the F1.

KATIE HAFNER: The F1 was the most powerful engine of its kind.

COLLEEN ANDERSON: The initial idea was that it would have a million pounds of thrust

KATIE HAFNER: And the plan was to use five of these engines. All together, that was an unbelievable amount of power.

COLLEEN ANDERSON: The power of the F1s was about 80 Hoover dams.

KATIE HAFNER: With the size of the huge F-1s in the Saturn V, combustion instability was a big problem. When NASA tested the engine, violent vibrations would build up in the chamber

COLLEEN ANDERSON: These could be incredibly destructive within less than a second. It could burn through the thrust chamber.

KATIE HAFNER: By 1963, when YY was back in Huntsville, NASA had already lost three F1 engines during testing because of combustion instability. That is a lot of work and money straight down the drain.

CAROL SUTTON LEWIS: Combustion instability was a grave concern at NASA. And the cause of it was complicated. There were so many variables the type of fuel, the pressure inside the chamber, the body and design of the rocket. And the occurrence of combustion instability was difficult to predict in any meaningful way. NASA feared the F1 engine, with its massive size and extraordinary power, would never get off the ground. They turned to multiple government contractors to investigate the issue.

MILTON CLARK: When they initially test fired at the F1 engine, um, they were getting hot spots, and the concern was burn through, the metal fatiguing

CAROL SUTTON LEWIS: Thats Milton Clark, YYs son. Hes done some research on his mothers work at NASA.

So NASA wanted to fix those hot spots in the F1 engine. And thats where YY came in.

MILTON CLARK: So her reputation in industry was that of a troubleshooter, which was why she was given that assignment.

CAROL SUTTON LEWIS: According to accounts from both YY and Milton, engineers had noticed that parts of the engine seemed to be overheating.

MILTON CLARK: Her job was to figure out why they were getting those readings.

CAROL SUTTON LEWIS: They were getting these temperature readings using thermocouple sensors. All you need to know about thermocouple sensors is that theyre a type of thermometer, and they use metal wires to take the readings.

YY was instructed to figure out what was wrong with the F1 design why it was producing these hot spots.

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NASAs Saturn V Rocket, the Moon Rock Box and the Woman Who Made Them Work Properly - Scientific American