It's not the only one, but Voyager is a great example of how NASA can take a minimally funded idea, have things break enroute, and still manage to get magnitudes more out of the project than originally planned. Voyager has been used for science that wasn't even conceived of when it was launched.
Makes you wonder what we could do if we put as much money into science as we do other things.
Fantastic!! Voyager is one of my favorite things that humanity has done. But I'm sad to learn from the article that it's expected to run out of power sometime after 2025.
Shout out to Carl Sagan for doing what is possibly the most romantic thing ever, which is taking the sound of a kiss between him and his partner Ann Druyan, putting it on a golden record, and sending it out of the solar system where it will live forever.
If anything, they are building them better. Their rovers now vastly exceed their original missions. Satellites now form an interplanetary internet network. We even have a helicopter on Mars! It's reached the point where it's playing spotter for the river, since they've run out of experiments to run on it!
There was 1 (experimental) mission into using ion drives. Multiple drives failed. 1 only lost its +ve ion thruster, another only it's -ve thruster. They managed to reconfigure it in flight. The 2 drives were interconnected via an FPGA processor on board. They rerouted the engines through the computer!
Don't get me wrong, Voyager I and II are amazing. However, given the same opportunity and funding now, the result would blow them away in almost every department, including longevity.