Design Features
The X-59 jet's elongated, slender body with the cockpit positioned high on the fuselage streamlines the aircraft's underbelly, preventing supersonic shockwaves from reverberating at the rear.
NASA is collaborating with Lockheed Martin to revitalize supersonic commercial flight by mitigating the sonic boom. Their X-59 Quiet SuperSonic Technology (Quesst) project aims to eliminate overland supersonic speed restrictions by addressing the sonic boom issue. Similar aircraft, such as the modified Northrop F-5E, demonstrated in 2003 that aircraft geometry can reduce sonic boom intensity. The X-59 is designed to go further, producing a sonic boom of only around 75 decibels, comparable to the sound of a washing machine.
Significance of Sonic Boom Reduction
Multiple aviation start-ups believe supersonic commercial travel is feasible and are developing, building, and planning to certify such vehicles within the next 5-10 years. Supersonic flight would revolutionize air travel, saving passengers significant time, as reported by Yahoo.
However, the primary obstacle remains the sonic boom, explains David Richwine, deputy project manager for NASA's X-59, a test aircraft designed to study and minimize the loudness and jarring effects of the boom. The sonic boom, first experienced when Chuck Yeager broke the sound barrier in 1947 in the Bell X-1, is the deafening noise caused by shockwaves formed as the aircraft surpasses the speed of sound. Initially hailed as a sign of progress, ushering in an era of supersonic flight, by the 1960s, the general public perceived the sonic boom more as a nuisance. In 1968, an F-105 flying over the Air Force Academy shattered 200 windows on a nearby chapel, injuring dozens. Between 1956 and 1968, the U.S. Air Force processed roughly 40,000 claims related to supersonic aircraft, paying out for broken windows and cracked plaster in homes.
Challenges Faced by Concorde
Even Concorde, the world's first commercial supersonic aircraft, failed to overcome the sonic boom issue. Developed by the British and French, Concorde's transatlantic flights routinely caused window breakage in many U.S. cities and its sonic vibrations alarmed local residents. In 1973, the U.S. Congress and aviation authorities around the world banned supersonic flight over land. With its expensive tickets and high fuel consumption, Concorde made its final flight in the UK in 2003.
Design and Features of X-59
The concept for the X-59 was first unveiled in 2018. NASA awarded Lockheed Martin a $248 million contract to develop the prototype jet. After computer modeling and wind tunnel testing, the X-59 was officially rolled out at Lockheed's Skunk Works facility in California in January 2024. The sleek, pointy-nosed aircraft measures 99.9 feet long and 29.5 feet wide, resembling a futuristic fighter jet with the cockpit positioned mid-fuselage. The vehicle is designed to travel at Mach 1.4 (925 mph). The X-59 reuses many aircraft components, including the landing gear from an F-16, the parachute and ejection seat from a T-38 supersonic trainer, and parts of the engine system used in the U-2 spy plane.
Positioning the engine at the front of the aircraft leaves the bottom smoother, preventing shockwaves from bouncing off the rear of the plane, thereby reducing the loudness of the sonic boom. The aircraft has undergone extensive ground tests and is scheduled to fly for the first time later this year. X-59 flights are expected to reach speeds of 1,074 mph at an altitude of around 55,000 feet, simulating the speed and altitude of a commercial supersonic aircraft. According to NASA, the collected data should help policymakers reconsider the ban on overland supersonic flight.
Cockpit Configuration and Testing
The mid-fuselage cockpit design means the pilot will not have a traditional forward-facing window view, relying instead on high-resolution cameras and a 4K interior display in the cockpit known as the eXternal Vision System. Once the X-59 takes to the air, it will undergo safety testing, followed by an acoustic assessment phase before NASA conducts a series of test flights over cities to gauge public response and determine if the technology has reached acceptable noise levels.
Summary
NASA and Lockheed Martin are collaborating on the X-59 Quesst project to make supersonic commercial flight a reality. The X-59 aircraft's design features, including a slender body, mid-fuselage cockpit, and front-mounted engine, aim to mitigate the sonic boom issue that has hindered supersonic flight over land. By conducting test flights over populated areas and using innovative cockpit technology, NASA hopes to gather data that will inform policymakers and potentially lead to the lifting of current supersonic flight restrictions.