I was watching one of the science shows and they called the Cassini probe “the most highly engineered object ever built” which sounded like fanciful writing to me.
How would you even decide what to measure? Man-hours of engineering billed? Years in development? Innovations required?
Is there really more engineering required to build the Cassini than the Burj Dubai?
Does it even make sense to ask such a question as what is the most highly engineered object built to-date?
How about something whose mass and operational energy is limited to the bare minimum and yet is able to function for 20 years? They can’t put high powered computers into probes for a variety of reasons- energy use, cooling needs, effects of radiation on small circuits, robustness, communication is far more limiting than computational power. But I would bet that there are many wasted grams of material on the overall spacecraft.
The Burj Dubai has dozens of people working in maintanence around the clock- it is certainly not supreme engineered.
Wouldn’t the fact that it’s lasted so much longer than its designed mission suggest that it’s poorly engineered? That probably means that they could have made it cheaper while still accomplishing all of their goals.
Was the goal to last at least X years? Or to last only x years?
Space Shuttle … by the measure number of individual parts, the number of individual parts custom made, number of individual parts that can break in normal usage; multiplied by number of uses … just look at the size of the thing …
However … the engineering isn’t especially advanced or challenging … just rocket fuel, a nozzle and crossed fingers …
We’ve discussed this before. And I think there was a consensus that a modern nuclear bomb is the best answer.
By most measures, it is the International Space Station. Besides being the most expensive single machine ever built (about $200 billion so far), it requires massive teams of research, development and support engineers from many different participating countries. Hardly anything else even comes close.
I am not sure exactly what question we are answering here. If it means “best engineered”, Voyager 1 gives just about anything a run for its money. It was launched in 1977, is now out of the solar system and still manages to transmit regular updates back home using a transmitter just about as powerful as a refrigerator light bulb (22.4 watts). It can also still respond to commands from Earth. That is just witchcraft in my opinion. It is expected to take care of itself because any serious failures are the virtual death of the deep space probe but it just keeps chugging along.
NASA even has a page to see where it is at any given time. Engineers can talk to it but it currently takes over 38 hours (at the speed of light) to send or receive a two-way signal but it will still happily do it using that refrigerator light transmitter and even take picture if you want it too (not that there is much to see in its current location).
Voyager - Mission Status (to get a feel for the numbers, notice that the distance from the earth and sun look almost the same).
Most the things listed here were not engineered from scratch. The whole standing on the shoulders thing…
So does most engineered include all of the previous engineering? If so, truly engineered objects from start to finish (like, for example, the great pyramids) will never compete with any modern object.
Smartphones sit atop a gigantic pile of engineering across many, many disciplines, and they are rapidly approaching commodity status.
It really depends on definitions.
If the OP is looking for a single artifact, then the Space Station or Voyager 1 are certainly good answers. But if he’s looking for a generic system, nothing comes close to the nuclear bomb. More engineering time, money, property, man-hours, and resources has been spent developing the nuclear bomb than anything else in history.
All are good answers, however
More money was spent on the development of the B-29 than the Manhattan project.
Putting this forward to the 21th century how about the 787 or the A380 ?
How about a secondary related question?
Most bang for the buck in terms of engineering and results from it ?
Voyager 1 and 2 ?
Pluto New Horizons ?
The gun that killed Archduke Ferdinand? 
Given that most of the hours spent computing for the Manhattan Project were women computerists (see here & here), it would be more accurate to say “person-hours”, I’d think.
no, it doesn’t. the average person thinks “good engineering” means “something designed the way I like it.”
I’ll nominate LIGO, then. It still stands on an awful lot of shoulders, of course, but it’s the first device in the world to successfully do what it does. Nothing else that has ever worked is even in the same broad category.
It’s also the clear winner if we take “most engineered” to mean “most precise measurements”, unless anyone can name any other device that measures to one part in 10^20.
It was designed to work in space for 11 years: almost 7 years enroute + 4 years of science observations. (Plus years of testing on the ground, probably.) So it’s only 10 years beyond its design life - not even twice as long.
Also, when you’re talking about reliability - if you design something so that there’s a 99% chance of it surviving for 10 years, there’s probably a 98% chance of it surviving for 20 years. Though of course, some things do have finite life determined by wear of moving parts, degradation from radiation, etc., and can’t be thought of in terms of mean time between failure.
Welsh long bows …
The total effort to create the conventional telephone system dwarfs al the others mentioned up-thread.
Then we built the internet alongside it.
A lot of these two systems’ claim to fame is simply their raw volume. But I’d argue that quantity has a quality all its own.
To be sure the OP’s raw question is unanswerable until we can define what “highly engineered” means. Greatest amount of bleeding-edgeness as measured by our interdisciplinary bleed-o-meter? Greatest parts count? Greatest gross weight? etc.
The question is too vague to answer as the OP mentions.
Is it size? Is it number of parts? Is it dependent upon the tech of the day (e.g. the pyramids are an amazing achievement even today but especially when they were built)?
For today I’d suggest a CPU. For sheer number of “parts” (transistor count) and complexity they are hard to beat.
But then the Space Shuttle or ISS is a lot harder to build.
See the problem?
