The "U-2" is still flying after its successor the Very famous "SR-71" was retired in the 1990's I believe.
The famous "Dragon Lady will finally be retiring. I am of 2 minds, part of me says that Satellites can do the same job but safer, and the other half says that you need something with a fast response time, and I guess they have drones for that now...
I got this from a 3rd party email from my work.
A U-2S flies with the avionics tech refresh upgrade in the cockpit for the first time.
Credit: Lockheed Martin