SoylentNews is people
SoylentNews
NASA says the preliminary design review of its Quiet Supersonic Transport (QueSST) project suggests it is possible to create a supersonic aircraft that doesn't produce a sonic boom.
NASA says "Senior experts and engineers from across the agency and the Lockheed Martin Corporation concluded on Friday that the QueSST design is capable of fulfilling the LBFD aircraft's mission objectives, which are to fly at supersonic speeds, but create a soft 'thump' instead of the disruptive sonic boom associated with supersonic flight today."
NASA's commercial supersonic technology project manager Peter Coen explains, in this video, that "the idea is to design the airplane so that the shock waves that are produced in supersonic flight are arranged in such a way that you don't have a boom. You have just a general kind of a gradual pressure rise that produces a quiet sound."
NASA's next step is finding organisations willing to build a working model of the Low Boom Flight Demonstration (LBFD) experimental airplane and fly it over American cities and towns to hear how much noise it makes. It's hoped those flights could start in 2021.
Nah, rather travel in the kind of zeppelin Sergei Brin is building.
(Score: 2) by fishybell on Wednesday June 28 2017, @02:54AM (1 child)
Recollection says the biggest reason they stopped the flights of the Concorde wasn't that one crashed, but that they weren't selling tickets like they needed. Fuel consumption and ticket prices were so high that continuing the flights was just not realistic after the perceived PR disaster that a single crash was.
Oh, and they also blamed terrorists [wikipedia.org].
(Score: 2) by Zinho on Wednesday June 28 2017, @03:00PM
My Materials professor at university had a slightly different take on this. According to him, the entire Concorde fleet needed refitting/replacement at once, and (as you say) they weren't making the money needed to pay for the fleet update.
The technical reason for the need to ground the fleet is interesting from an engineering standpoint. Unlike steel, Aluminum and Titanium are susceptible to fatigue cracking under cyclical loads of any magnitude: steel has a minimum threshold of stress needed before a crack will start, whereas Al and Ti will start to crack no matter how low the stress is as long as there is a load-unload cycle going on.
On most airplanes there are indicator systems to watch so you know when to take a part out of service. For example, there's an engine rotation counter so you know when to replace your aluminum engine block; there's also a machined-in crack initiation point on aluminum support struts placed where it's easy to inspect, and when the diagnostic crack reaches a certain length you pull it out of service and replace all the aluminum parts on the plane.
Unfortunately for the Concorde, the entire plane was made of Titanium, and the frames were reaching the end of their service life. The company knew that there were probably hard-to-find cracks throughout the structure, and it would soon be unsafe to fly them anymore - structural failure in flight is even harder to brush off than a popped tire on takeoff. Since they were all built at about the same time they all needed replacing at the same time. The entire fleet was basically good for nothing but scrap for melting down to forge new parts. The company either hadn't saved the money needed to rebuild, or decided that they'd rather pocket the cash and shut the service down rather than spend it on new planes that wouldn't deliver a good return on investment.
That's my professor's story, anyhow, and he's sticking to it. It at least sounds plausible from a technical and financial point of view.
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin