Source report. The experimental aircraft reached Mach 1.2, while dedicated acoustic evaluation remains ahead.
Source: NASA Quesst. Original source published 4 September 2026. Published on Alder Atlas: 14 September 2026.
A new flight-test milestone
NASA’s X-59 completed its 25th flight on 21 August, according to an update published on 4 September. The 72-minute flight reached approximately Mach 1.2 and 49,000 feet during testing based at Armstrong Flight Research Center in California.
Speed is only part of the question
The aircraft is being used to investigate quieter supersonic flight. Completing another flight helps expand the test record, but this particular outing did not establish the aircraft’s acoustic performance: sonic booms from a chase aircraft masked its sound.
Listen for the later results
NASA described further acoustic evaluation as a task for later in 2026. That distinction matters for any claim about what people on the ground would hear. A successful supersonic test flight and evidence of reduced community noise are related milestones, but they answer different questions.
Sources & further reading
This is an independently worded, source-based report prepared with AI assistance for the Alder Atlas editorial project. It is not first-hand reporting.