Lockheed Martin X-59 Quesst
The Lockheed Martin X-59 Quesst ("Quiet SuperSonic Technology"), sometimes styled QueSST, is an American experimental supersonic aircraft under development by Lockheed Martin for NASA's Low-Boom Flight Demonstrator project. Preliminary design started in February 2016, with the X-59 originally planned to begin flight testing in 2021.
Source: Wikipedia — Lockheed Martin X-59 Quesst (CC BY-SA 4.0)