Having a large number of people in the chain isn't the problem, it's that no manufacturing process is perfect and defects in design or production are often not obvious until you've tested the item in the field.
Further, since it's not practical to test things on Mars, so you can imagine how difficult this can be for the engineers here on Earth.
The process described here is typical of many companies because it's not possible for one person to do all of these steps. The level of expertise required is too high. You may be a great mechanical engineer, but do you know about the performance characteristics of the hundreds of different kinds of grease? About the way the sleeve should be machined? There's a list of specializations thousands of items long, and at best you'll be able to truly master only a small percentage of these even through a whole career.
The ultimate reason technology is unreliable is because the world is a complicated, crazy place that often exposes you to situations you're not prepared for.
Further, since it's not practical to test things on Mars, so you can imagine how difficult this can be for the engineers here on Earth.
The process described here is typical of many companies because it's not possible for one person to do all of these steps. The level of expertise required is too high. You may be a great mechanical engineer, but do you know about the performance characteristics of the hundreds of different kinds of grease? About the way the sleeve should be machined? There's a list of specializations thousands of items long, and at best you'll be able to truly master only a small percentage of these even through a whole career.
The ultimate reason technology is unreliable is because the world is a complicated, crazy place that often exposes you to situations you're not prepared for.