Mach 5 is enough- Boeing
Having spent the last two decades traveling across continents on 18-hour flights; sometimes spending 24 consecutive hours landing at 3 countries and therefore airports; the sound of supersonic flying means the world to my painful, broken back and perpetually jet-lagged body and mind.
A Mach 5 aircraft can also be built more affordable than an aircraft that goes Mach 6, 7, or 8 because it would use readily available titanium for its structure instead of materials like composite ceramics to manage the heat produced at higher speeds.
The G-force feeling upon takeoff would last 12 minutes as the plane accelerated to cruising speed but I can only imagine the cruising-altitude experience. The view of the earth’s curvature at the horizon and the blackness of space above would be such an upgrade to bar-booze-movie-sleep travel. Will this be the end of travel as we know it? And yes- just add the autonomous bit to it. A cherry on the proverbial cake.
An aircraft flying Mach 5 (Mach numbers reflect the plane's speed relative to the speed of sound in the medium it's moving through. Mach 1 means it's going the speed of sound in that particular medium. Mach 2 means it's going twice the speed of sound. Guinness World Records recognized NASA's X-43A scramjet with a new world speed record for a jet-powered aircraft - Mach 9.6, or nearly 7,000 mph. The X-43A set the new mark and broke its own world record on its third and final flight on Nov. 16, 2004.) can fly the Atlantic Ocean in 2 hours and the Pacific in 3. A Mach 5 aircraft can also be built more affordable than an aircraft that goes Mach 6, 7, or 8 because it would use readily available titanium for its structure instead of materials like composite ceramics to manage the heat produced at higher speeds.