It's a repurposed U-2 high-altitude observation aircraft. At Flight Level 600, that's 60,000 feet above sea level. Which is really up there for any aircraft.

It's a repurposed U-2 high-altitude observation aircraft. At Flight Level 600, that's 60,000 feet above sea level. Which is really up there for any aircraft. I believe there are two of these still in operation by NASA. 30 (!) years ago, I met a couple of engineers who were working on an instrument package that was flying on the ER-2 at the time. Measuring atmospheric and environmental conditions of the stratosphere. I just saw a YouTube video of one of these landing a few days ago, good chance it's the same aircraft! https://youtu.be/f8uzM-SyZfU https://youtu.be/f8uzM-SyZfU