Crushing The Hopes Of Tomorrow

VanCleave and Olden in front of the test article

Dee VanCleave and George Olden get paid to break things.

Not only that, they get paid to take physical manifestations of hopes and dreams for the future, and crush them. Under the weight of 50 years of history, no less.

Dee and George are test engineers at NASA’s Marshall Space Flight Center. They test hardware to analyze its load limits and related failure modes. In other words, you give them something, and they’ll tell you how much pressure it takes to cause it to buckle or break. And what happens when it does.

They do this using a facility designed for the development of the Saturn rockets that went to the moon. Later, it was used to do very unpleasant, and messy, things to test versions of the space shuttle’s external tank.

Now, all of that is pretty cool.

So I’m ashamed to admit, when I first heard about the test they’re doing Wednesday, I was a bit blasé about it.

We were called into a meeting to discuss providing education support for tomorrow’s test. The test, we were told, would involve taking a 27.5-foot-wide and 20-foot-tall cylinder, putting it in the test equipment, and crushing it like an aluminum can. OK, at that point, it sounded pretty cool.

But then it was explained that in this case “crushing” actually means slightly buckling in a way that you probably won’t be able to see easily. Less cool. But it will probably make a loud noise. Uh … kinda cool?

But then Heather and I got to go meet Dee and George at the facility and find out more about what was going on.

First, just being there was cool.

The particular room and equipment that will be used for tomorrow’s test hasn’t been used since the mid-1970s. You can see marks on the equipment from past tests, putting loads on Saturn rocket stages and shuttle external tanks. George noted that if you know the diameters of the vehicles, you can tell what marks were left by what hardware. We went up into the catwalks in the top reaches of the high bay, largely untouched since the 1960s.

It was one of those moments that I love when I was aware of the continuity — George and Dee and Heather and I work for the same NASA that went to the moon, and are continuing the work today that von Braun and Faget and Kraft and Gilruth and others started 50 years ago.

But, also, what they will be doing is cool.

If you build a rocket, you have to know that it’s going to be strong enough to withstand the crazy variety of loads it will experience during launch — axial loads from vehicle weight and thrust and air pressure and shear loads from wind and burning fuel and torsional loads from rolling and many many many others.

It’s the great conundrum. Making the rocket stronger adds weight which requires more fuel which adds weight which requires more fuel, etc. Make it too light, however, and it comes apart during launch. Not a good day.

Engineers today are still following rules on how strong a rocket needs to be that were born, in part, in that same room decades ago. Hardware was tested until it broke, and that told how strong it needed to be. Back then, it was a different age — analog and less precise. So engineers erred on the side of caution, going with stronger instead of lighter when there was uncertainty.

Today, there’s better equipment — computers and sensors and video and all sorts of other toys that will allow the measurements to be more precise. Tomorrow’s test is verifying a new computer model about what sort of loads a vehicle can withstand. If the testing validates the models, it means engineers will know more precisely how strong their vehicle needs to be. Smaller margins will result. Lighter instead of stronger.

The difference could be substantial. The weight savings will make rockets smaller or more powerful. They will make access to space easier and cheaper. Tomorrow’s test may not be as telegenically impressive as if it were the equivalent of crushing an aluminum can. But it’s revolutionary.

Appropriate that in a room drenched in the past, the future will begin tomorrow.

Heather’s got a great post about the test on her NASA Taking Up Space blog.