What makes a rocket engine different than a child's balloon?

I took a trip to several space centers a few years ago, and I learned a little about product development along the way.

In the first mercury capsule each wire in the compartment was run separately. They were quite chaotic.

In the second, you could tell that they knew more about what needed to be run from place to place. There were big bundles of wires, but there were still many wires that were run seemingly as afterthoughts.

In the third, almost all the cables were run in bundles, with just a couple that were added after the fact.

The evolution from generation to generation was quite apparent, and impressive. I'm sure that the wiring was just the tip of the iceberg as far as their improvement over time. Getting close and seeing the changes gave me a sense of the pride and excitement that the builders must have experienced as they discovered new problems and solutions.

Sometimes I feel like that when I am working on my startup.

I wish they'd go into the nozzle geometry & physics!

Summary: A rocket engine is more powerful.