Why do we still expect “successful failures” on rocket launches and not just scale up or scale down the same design on successful rocket ships and launch pads to make bigger or smaller ships with more stable structural material?
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You’d think that it’d be that simple. Unfortunately the scaling here is non-linear, it is often exponential, if it scales at all. That is to say, if you double the height of the rocket, you don’t double it’s weight. That kind of scaling would be linear (proportional) but in fact, if you double it’s height you increase it’s volume (ergo its mass, ergo its weight) EIGHT times.
That’s just one simple issue with the scaling. The forces involved do not scale proportionally, nor does the amount of fuel. Nor do the aerodynamics since the volume of air that needs to be displaced is also related exponentially. All this combined means that the materials used in construction won’t be subjected to linear transformations of the stresses. Same is true for the fuel seals and just about every other component.
With something as complex as a rocket (this IS rocket science after all) it’s incredibly difficult to build a reliable mathematical model and scale it to suit. There are so many variables and so many unknowns. And every mathematical model, by its very nature, is a simplified one.
The recent launch was a test, so they can gather data. Now that they have that data, they feed it back into the mathematical model and refine it, tweak the papameters, add or change variables etc. it’s a highly iterative process. Build, test, refine, repeat. That’s why the launch is being considered a success even though the rocket itself failed. If we can understand the failure points, we can engineer them out. Next time that won’t fail, but something else now will. Reset and go again.
Usually these process are not so public and not on such a huge scale. Which is why the failure seems more of a failure than it actually is. To the engineers it’s just part of the process and not deemed a failure at all.
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