Watch the rollout of The X-59 Quesst supersonic aircraft live from Lockheed Martin's Skunk Works facility in Palmdale, California.

The Lockheed Martin X-59 Quesst ("Quiet SuperSonic Technology"), sometimes styled QueSST, is an American experimental supersonic aircraft being developed at Skunk Works for NASA's Low-Boom Flight Demonstrator project. Preliminary design started in February 2016, with the X-59 to be delivered to NASA in 2021 for flight testing in 2023. It is expected to cruise at Mach 1.42 (1,510 km/h; 937 mph) at an altitude of 55,000 ft (16,800 m), creating a low 75 Perceived Level decibel (PLdB) thump to evaluate supersonic transport acceptability.

A model in a wind tunnel at NASA Langley, September 2017
In February 2016, Lockheed Martin was awarded a preliminary design contract, aiming to fly in the 2020 timeframe. A 9% scale model was to be wind tunnel tested from Mach 0.3 to Mach 1.6 between February and April 2017. The preliminary design review was to be completed by June 2017. While NASA received three inquiries for its August 2017 request for proposals, Lockheed was the sole bidder.

On April 2, 2018, NASA awarded Lockheed Martin a $247.5 million contract to design, build, and deliver in late 2021 the Low-Boom X-plane. On June 26, 2018, the US Air Force informed NASA it had assigned the X-59 QueSST designation to the demonstrator. By October, NASA Langley had completed three weeks of wind tunnel testing of an 8%-scale model, with high AOAs up to 50° and 88° at very low speed, up from 13° in previous tunnel campaigns. Testing was for static stability and control, dynamic forced oscillations, and laser flow visualization, expanding on previous experimental and computational predictions.

From November 5, 2018, NASA was to begin tests over two weeks to gather feedback: up to eight thumps a day at different locations to be monitored by 20 noise sensors and described by 400 residents, receiving a $25 per week compensation. To simulate the thump, a F/A-18 Hornet is diving from 50,000 ft (15,200 m) to briefly go supersonic for reduced shock waves over Galveston, Texas, an island, and a stronger boom over water. By then, Lockheed Martin had begun machining the first part in Palmdale, California.

In May 2019, the initial major structural parts were loaded into the tooling assembly. In June, assembly was getting underway. The external vision system (XVS) was flight tested on a King Air at NASA Langley. This is to be followed by high-speed wind tunnel tests to verify inlet performance predictions with a 9.5%-scale model at NASA Glenn Research Center.

The critical design review was successfully held on September 9–13, before the IRB report to NASA's Integrated Aviation Systems Program by November. Then, 80–90% of the drawings should be released to engineering. The wing assembly was to be completed in 2020. In December 2020, construction was halfway completed with the first flight planned for 2022

After flight-clearance testing at the Armstrong Flight Research Center, an acoustic validation will include air-to-air Schlieren imaging backlit by the Sun to confirm the shockwave pattern until September 2022.NASA will conduct flight tests over U.S. cities to verify the safety and performance of the X-59's quiet supersonic technologies and evaluate community responses for regulators, which could enable commercial supersonic travel over land.

Community-response flight tests starting in 2023–2025 will be used for ICAO's Committee on Aviation Environmental Protection meeting (CAEP13) establishing a sonic boom standard. The results of the community overflights will be delivered to the ICAO and the FAA in 2027, allowing for a decision to be made to revise the rules on commercial supersonic travel over land in 2028.

Quesst is NASA's mission to demonstrate how the X-59 can fly supersonic without generating loud sonic booms, and then survey what people hear when it flies overhead. Reaction to the quieter sonic "thumps" will be shared with regulators who will then consider writing new sound-based rules to lift the ban on faster-than-sound flight over land.

More on this NASA Aeronautics mission: [ Ссылка ]

Credit: NASA

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