CONFIRMEDDate confidence: CONFIRMEDStated as firmHow firmly the source words the date: confirmed, scheduled, estimated, delayed or unverified.Show all CONFIRMED pins85% CONFIDENCEOverall confidence: 85%How well the pin's source and references back up its dates.Weighted average of how firmly 5 references, the source included, support the pin's start and end times; a reference counts half as much for every 180 days older than the newestShow all pins at 75% confidence or betterHappened as dated, per nasa.gov[1][3][4]: the X-59 "marked a major milestone Friday, June 5, when it flew faster than the speed of sound for the first time."
The quiet supersonic demonstrator reached Mach 1.1 and 43,400 feet on an 81-minute flight from Edwards Air Force Base, the first time it exceeded the speed of sound. A NASA F-15 chase plane flew alongside, its own booms drowning out anything the X-59 made.