https://en.wikipedia.org/wiki/Lockheed_U-2#TR-X
TR-X
In August 2015, the 60th-year anniversary of the U-2 program, Lockheed Martin's Skunk Works revealed they were internally developing a successor to the U-2, referred to as the UQ-2 or RQ-X, combining features from both the manned U-2 and unmanned RQ-4 Global Hawk and improving upon them. Disclosed details say the design is essentially an improved U-2 airframe with the same engine, service ceiling, sensors, and cockpit, with the main differences being an optional manning capability (something Lockheed has proposed for the U-2 to the Air Force several times but has never gained traction) and low-observable characteristics.
The Air Force has no requirement or timeframe for a next-generation HALE platform, but Lockheed sees a future need and wants something in development early. Having the option of an onboard pilot is seen as a deterrent because it can be used in situations where unmanned aircraft would more likely be engaged, while the possibility of killing a person and the resulting consequences could add to its survivability. The company's last attempt to create a stealthy unmanned aircraft was the RQ-3 DarkStar, which never made it past flight testing and was cancelled.[20] Plans for a U-2 replacement would not conflict with development of the SR-72, another Lockheed project to create a hypersonic unmanned surveillance plane, as it would be suited for missions that require greater speed for time-sensitive targets.[21]
The company released a notional artist’s impression of the TR-X aircraft at an Air Force Association conference in Washington on 14 September 2015. Its name was changed to mean "tactical reconnaissance" to reflect its purpose as an affordable peace and wartime ISR aircraft, distinguishing it from strategic, penetrating SR-71-class platforms. Size, and thus cost, is kept down by having less endurance than the Global Hawk, which is not seen as a disadvantage since the RQ-4 rarely flies its whole 34-hour capability, usually flying for one day or less. The TR-X concept is aimed squarely at Air Force needs, and is not currently being marketed to the CIA or other government agencies. It would have increased power and cooling to accommodate new sensors, communication equipment, and electronic warfare suites, and perhaps even offensive or defensive laser weapons. TR-X could be ready for service in the 2025 timeframe.[22][23]