Planefag reporting: U-2 spotted flying over the UK

The Lockheed U-2, nicknamed "Dragon Lady", is an American single-jet engine, high altitude reconnaissance aircraft operated by the United States Air Force (USAF) and previously flown by the Central Intelligence Agency (CIA). It provides day and night, high-altitude (70,000 feet, 21,300 meters), all-weather intelligence gathering.

https://www.airforcemag.com/budget-elicits-confusion-over-fate-of-u2/

https://en.m.wikipedia.org/wiki/Lockheed_U-2