What makes the U2 quite amazing is not just that it's a 70 year old design still in operation.
It's also that the U2 was developed by Lockheed Skunk Works on a $22.5 million contract, where they delivered 20 working aircraft in less than 2 years from project start and went $3.5 million under budget. They paid back the money. And as a bonus deliverable, the team also developed a new testing site with extra long paved runway, hangars, workshop etc. on a salt flat known as Area 51.
It's also that the U2 was developed by Lockheed Skunk Works on a $22.5 million contract, where they delivered 20 working aircraft in less than 2 years from project start and went $3.5 million under budget. They paid back the money. And as a bonus deliverable, the team also developed a new testing site with extra long paved runway, hangars, workshop etc. on a salt flat known as Area 51.