1. The Kids Arrive
It took a while for the kids to come up from the library. Three of them arrived first, because there were no more computers downstairs, and the boys needed to put together some kind of storyboard. The sat down at Mr. Roth’s desk in the front and opened some laptops.
“Not that computer, boys,” Mr. Roth told them. “Mr. Hasan is going to use that one.”
A few minutes later, the other kids arrived. The previously quiet room was now a loud, chaotic hustle and bustle as two classes worth of fourth graders filed in and began promptly to sit on the floor as close as humanly possible to where I was standing.
“What are you going to talk about?” one of them asked.
“Well you’ll find out in a second,” I said.
2. Rockets with Stages
It really doesn’t matter what Mr. Roth asks me to talk about, I can usually figure out some way to bring rockets into the discussion. Today Roth’s chosen topic was Analyzing Data for Meaning, Including Making Connections and Finding Patterns.
I don’t know about you, but fourth grade was never quite like that for me!
I had a plan. It involved rockets. Here’s how it went…
First, I showed them a picture of a NASA Mercury Redstone launch. We talked about how simple the launch pad looked. We talked about how there was only one astronaut and how it was only a suborbital flight. We talked about the red escape rocket on the top. And we talked about how there was only one stage on the Redstone.
“I’ll explain what a stage is in a second,” I told them.
Second, I showed them a picture of a NASA Gemini Titan launch. We talked about how that rocket is my favorite all time rocket because the exposed rocket nozzles at the bottom look so cool, which made a father at the back of the room smile. We talked about how there were two astronauts and how the launch pad was a bit more complex. And we talked about how there were two stages on the rocket.
“What about the Saturn?” one of the students asked.
“Funny you should ask,” I said, and I put my next picture on the screen.
So third, I showed them a NASA Saturn V on the mobile launch platform. We talked about how big the crawler is, which was easy to show them because of how tiny the trucks on the ground seemed in comparison. We talked about how there were three astronauts, how only two would actually land on the moon, how Apollos 11, 12, 14, 15, 16 and 17 landed twelve astronauts. Of course, we talked a bit about Apollo 13, but I told them was a story for another day. And I showed them how the rocket has three stages.
And then we talked about what stages are for, about how it’s expensive to push a lot of stuff into space, about how when the rocket engines burn and the fuel gets used up you end up pushing empty tank stuff into orbit unless you drop it away. At which point…
Fourth, I showed them (of course) a NASA Space Shuttle launch. We talked about the really complex launch pad. We talked about the external tank and the orbiter and the solid rocket boosters. We talked about how the orbiter flew back to earth and got refurbished to fly again. And we talked about how even though there were not stages stacked on top of one another, this rocket still had stages, because the solid boosters dropped off after their fuel was all used up.
3. Solid Rocket Boosters
And with that cool-picture-based intro to the history of America’s manned rockets, we talked a bit about the solid rocket boosters themselves.
“Have you ever seen model rockets?” I asked. A lot of them had.
“These are just like those, except they’re really, really big.”
And we talked about how the fuel isn’t liquid but solid. We talked about how there’s a hole running up the middle of the boosters which is where the combustion takes place. (Yes, fourth graders can handle the word, combustion.) We talked about how the boosters were so big that they had to be built in segments and assembled once they arrived at the cape. And we talked about O-rings.
To describe the O-rings and how they work, I pushed my hands against my cheeks and squeezed my face while I talked. I told them (with my cheeks squeezed and my lips sticking out) how the rubber O-rings sealed those joints and plugged holes, so that the fire from the combustion couldn’t leak out.
“Do you understand what I’m saying?” I asked with my face contorted beneath my pressing hands and my voice sounding a little like Popeye.
“Yessss,” they said.
4. Ice On the Pad
I suspect you might have an idea where this is going, at this point.
The next picture I showed them this picture of ice on the pad on the day that STS-51L was supposed to launch.
We talked about how it was colder than usual that morning. We talked about how when it was cold, the O-rings got stiff and couldn’t seal the joints quite as well as they usually did. And we talked about how NASA had to decide whether or not to launch.
“No!” the kids said. “They shouldn’t launch.” (Keep in mind that these kids were born in 2007, more than twenty years after that day, so they didn’t know exactly where this story was going.)
So we talked a little bit about politics. About how NASA had promised that the Space Shuttle would make spaceflight cheap, about how they had promised to fly the Shuttle several times per year, and about how NASA management was under a huge amount of pressure to launch that day.
We talked about how a lot of engineers didn’t want to launch, and how they tried to make their case to the managers. And I showed them this diagram that the engineers used to try to explain their logic.
It’s a complicated diagram but we talked about it at length. And we talked about how there had been damage to the O-rings before, which was shown in the diagram. And we talked about how the diagram showed the temperatures on the day of launch of each of the (many) Shuttle flights that had already successfully flown.
And all the kids agreed that it was hard to understand the diagram.
“So imagine how hard it was for the managers to understand what the engineers were trying to tell them.”
5. Making Connections and Finding Patterns
So now we come to the reason Mr. Roth had asked me to come that day. It wasn’t about rockets. (It rarely is.) And it wasn’t about O-rings or a cold day of launch.
“Suppose,” I said, “that we took those data and drew them a different way.”
And I showed them this picture drawn shamelessly from the work of Edward Tufte (upon whose insight this discussion was entirely based).
I explained how this diagram had the same data. It had the day-of-launch temperatures (horizontal axis). It showed when they found O-ring damage (black dots). And it had the severity of the damage (vertical axis), something that is actually present but very hard to fully understand on the original diagram.
“Suppose that this was the diagram we showed to the managers to help them understand our logic, to help them understand why we felt it was dangerous to fly.”
And I pointed to the diagram, starting on the right and moving slowly to the left, pointing out to the kids how as the weather got colder, there was more O-ring damage, and how as it got even colder, the damage got worse, as can be seen by the black dots rising off the bottom of the chart.
And then I pointed out the grey-shaded temperature zone on the far left.
“This was the temperature on that morning.” I said.
The kids gasped. The eight and nine year old fourth graders gasped in recognition of what they were being shown. Those fourth graders instantly understood that what they were looking at meant this.
6. In Conclusion
We all sat there for a few moments (although not in silence, because… well because these were fourth graders).
“So what happened,” someone asked from the darkness of the room.
And I flipped to my last picture.
There was instant silence in the room. Every single one of them was staring in disbelief at the screen.
I stood there in silence, too, not quite sure if I was going to be able to continue, because it’s hard for me to look at that picture. It’s hard for me to imagine the pain those engineers carried with them for the rest of their lives.
I stood there in silence and then said in a trembling voice, “They all died.”
And the room was silent a bit longer.
“So this is why I’m telling you this,” I said. “Your job when you’re an engineer or a scientist or a writer, your job isn’t just to do the fun stuff (building rockets). Your job is to tell other people what you’re thinking, to help them understand.”
“And when you write in your science notebooks, it’s not just about jotting down some scribble-scrabble. When your teachers or your parents tell you to show your work, there’s a reason for that. When they ask you to be neat, there’a a reason for that. When they ask you to put units after the numbers, it’s not just because they’re trying to make you do extra work.”
“Your job in life is to tell a story, to help other people around you understand, to explain your thinking in a way that helps them make the connections and see the patterns that you see.”
And with that, it was time for lunch.