NASA To Test 'Quiet' Supersonic Flights Over Texas (cnn.com) 85
NASA announced it will publicly demonstrate a quiet supersonic aircraft near the coastal resort city of Galveston, Texas, to ensure that its prototype really will be barely audible when it crosses the sound barrier. CNN reports: If NASA's experimental project -- formerly known as the X-plane or "Low-Flight Flight Demonstrator" but recently renamed X-59 QueSST -- works, it should help make supersonic flight more economical. From November, NASA will use supersonic F/A-18 Hornet jets over Galveston to mimic the sonic profile of the X-59 while a group of around 500 residents document the noise levels -- if there are any. By performing dives at the speed of sound, the jets will produce two types of sonic boom in order to truly determine the sound they produce on the ground.
According to NASA, Galveston was chosen as the testing area as it's located near the Gulf of Mexico, allowing the fighter jets keep louder sonic booms out to sea, while hurling quieter sonic "thumps" into the city. The secret to the plane's noise-reducing ability is its uniquely shaped structure, designed so that supersonic shockwaves don't build up into powerful sonic booms.
According to NASA, Galveston was chosen as the testing area as it's located near the Gulf of Mexico, allowing the fighter jets keep louder sonic booms out to sea, while hurling quieter sonic "thumps" into the city. The secret to the plane's noise-reducing ability is its uniquely shaped structure, designed so that supersonic shockwaves don't build up into powerful sonic booms.
Good (Score:2)
It's pretty cool looking too. And who wants exploding tomatoes, or hearing loss?
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And who wants exploding tomatoes, or hearing loss?
"Where's the kaboom? There was supposed to be an Earth-shattering kaboom!"
If they dive too low (Score:2)
Re: Huh? (Score:1)
Re:Huh? (Score:5, Informative)
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You should read the articles. They give some more insight.
Looks like the modified F/A-18 are able to produce the needed effect only performing dives, not in normal straight flight. They are anyway modified fighters, and the modification looks quite expensive it's common for a prototype to cost way more than the final product it's being used to test).
The final object will allow testing in straight flight and pose basis for further development towards applying the technology to actual transportation airplanes
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Speak for yourself, monkey boy. I go to India and Japan a couple times a year. I could definitely use flights that get me there fast enough that my body clock can be more or less in sync with local time.
Doesn't matter how long it takes to get there, that place will still be the same amount of hours before or behind only it will be even worse because you'll just be even more out of whack.
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I think I'd be less tired if I didn't have to spend 12 hours on an airplane, especially in an economy class seat.
Unfortunately supersonic transport is likely to be insanely expensive.
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If you can't afford first class, and your complaint specifies that you're not talking about first class seating, you're not going to be able to afford this kind of travel.
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I agree that flying across the Pacific is very tedious. Hated it myself. But consider that the heavily traveled route from West Coast North America to East Asia is (or can be) almost entirely over water and could be flown at supersonic speeds with a short subsonic segment at each end. That's what Concorde did across the North Atlantic My understanding is that It isn't done that way because its really hard to design an aircraft that can carry enough fuel to travel 10000km at supersonic speeds and also ca
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Current jets can make sonic booms. That's due to the shape of the aircraft and the wings so that there are two sonic booms due to areas of high air pressure. They can reduce that by a small amount by making minor changes to the airframe and wings:
https://www.youtube.com/watch?... [youtube.com]
With the X-59, they completely redesign the airframe and wings so that the pressure waves cancel each other out rather than reinforce each other.
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The awesomeness of that video cannot be overstated...
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The first A in NASA stands for Aeronautics [wikipedia.org] (The study, design & manufacturing of flying machines).
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National AIR and Space Administration, Einstein. It has nothing to do with space, but everything to do with air.
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Rein. If you can't spell it, don't use it....
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Trump, reign these people in.
Rein. If you can't spell it, don't use it.
Dunno - the original seems to describe his fundamental plan pretty accuractely.
Sonic booms are not caused by crossing the barrier (Score:5, Informative)
"its prototype really will be barely audible when it crosses the sound barrier."
Sonic booms are caused by going faster than the speed of sound. They are not caused by reaching the speed of sound. This is why the boom is a potential problem - it is heard along the entire supersonic flight path, not just at the beginning.
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The state of trespassing is caused by my stepping into your property without your permission. You're just arguing the imprecision of the English language now.
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You could interpret that "when" as meaning "once it enters supersonic flight". Maybe there is less room for interpretation in American English.
It's not small (Score:2)
Much hubris in the announcement... (Score:2)
From the link:
NASA’s newest experimental aircraft, designed with quiet supersonic technology and intended to help open a new era in faster-than-sound air travel over land, will forever be known in the history books as the X-59 QueSST. The U.S. Air Force, which is the government entity responsible for assigning X-number designations and the popular name associated with the aircraft, officially informed NASA of their decision on June 26.
“For everyone working on this important project, this is great news and we’re thrilled with the designation,” said Jaiwon Shin, NASA’s associate administrator for aeronautics. “I’m confident that the contributions the X-59 QueSST will make to our nation and the world will ensure its place among the greatest NASA X-planes ever flown,” Shin said.
"among the greatest?"...nope, don't think so...
or "Low-Flight Flight Demonstrator" (Score:3)
or "Low-Flight Flight Demonstrator"
So... it's a Low Flight Flight Demonstrator Demonstration?
I Can't believe it... (Score:4, Funny)
I'm stunned. Shocked. Is this even possible? I never believed this could happen in my lifetime.
Galveston is a resort these days?
The Sonic Fart Engine. (Score:4, Funny)
"The secret to the plane's noise-reducing ability is its uniquely shaped structure, designed so that supersonic shockwaves don't build up into powerful sonic booms."
Why did my childish mind translate this as NASAs new Sonic Fart Engine, equipped with titanium SBD valve technology?
(Spectator)"Sir, is this plane fast?"
(Captain Texas, US Air Force) "Quicker than a sonic fart in high wind, yes, Ma'am."
Still not economical (Score:2, Informative)
It should help make supersonic flight more economical.
Supersonic flight still will not be more economical. As this video by Wendover Productions [youtube.com] explains, the biggest cost of supersonic flights is the fuel. The Concorde flies 14 miles per gallon of fuel, while the Boeing 787 flies 104 miles per gallon. Also consider the Concorde only carried 128 passengers, while the 787-9 can carry 290. Doing the math, on a 3,470 mile flight from New York to London, a Concorde would consume 1.936 gallons of fuel per pa
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The target audience values time more than money.
This.
But that's going to make the SJWs hyperventilate even more when they hear a quiet thump overhead. It's not just passengers flying quickly. It's rich passengers.
Re:Still not economical (Score:5, Informative)
The Concorde flies 14 miles per gallon of fuel, while the Boeing 787 flies 104 miles per gallon. Also consider the Concorde only carried 128 passengers, while the 787-9 can carry 290. Doing the math, on a 3,470 mile flight from New York to London, a Concorde would consume 1.936 gallons of fuel per passenger, while a 787-9 would consume only 0.115 gallons per customer.
You’ve misunderstood the fuel economy numbers you quoted, which should have been readily apparent as soon as you tried to suggest that a Concorde got similar fuel economy (14 mpg) to an older car. The original numbers you gave were already on a miles per gallon per passenger basis [wikipedia.org], so dividing them again by the number of passengers gives you a useless number.
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I think your numbers are not correct. I suspect that the 14 miles per gallon are already per passenger, as well as the 104 for the 787 Or was that supposed to be 0.115 gallons per customer per mile?
7,635 nmi to burn 33,384 gallons is 0.228 nautical miles per Gallon, or 66 nmi per passenger per gallon for 290 passengers.
Re:Still not economical (Score:5, Insightful)
That's not exactly a fair comparison. A 1970's era subsonic airliner would use a lot more fuel than the 787 as well.
This report puts Concorde per passenger fuel consumption at about twice a 707, four times a contemporary 747, essentially the same as a business jet and a lot better than a train.
One of the reasons why Concorde was so expensive was that there were only a few built, to fly very specific routes that were mostly over water, and even so, there were generally fairly long subsonic legs at the beginning and end. Those are expensive because supersonic aircraft tend to drink fuel when flying subsonic, and if you have to do it at the end of your flight you have to carry all that extra fuel all the way.
Opening up more routes to supersonic aircraft would make them a LOT more economical. Barring some groundbreaking innovation, supersonic would still be more expensive than subsonic, but not by nearly as much as the Concorde was.
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Report: https://www.flightglobal.com/F... [flightglobal.com]
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Edit #2: a lot *worse* than a train.
Apologies, American-style MPG fuel economy is the reciprocal of the L/km we use.
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Yes it is a fair to compare a modern subsonic airliner to Concorde.
Subsonic airliners have gotten much more fuel efficient since the 1970s by switching to higher bypass ratios [wikipedia.org]. Basically, instead of the engine operating as a turbojet and blasting air out the back to push the plane forward, part of the power generated by the engines (more than 90% in modern designs) is diverted to spin duc
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Turbofans are not propellers. Turbofans work fine on supersonic aircraft, and are installed on many military jets. You generally wouldn't use a high bypass tubofan, and might even go with a turbojet for a plane that flies mostly supersonic because low-bypass and turbojets get more efficient at high speed. There has also been a lot of development in turbojets and low bypass turbofans since the 1970s. This is demonstrated by the super cruise capabilities of fifth generation fighters.
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The big problem with Concorde was the noise. That limited the routes it could fly. When Conc
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I agree, especially on the Concorde. The Concorde used Rolls-Royce Olympus 593 _turbojets_, which were notoriously fuel-inefficient and noisy at the same time.
But we've come a LONG way since the Concorde was designed in the 1960's. Thanks to modern computational fluid dynamics, we now know how the sonic boom happens, and by carefully shaping the entire plane itself, we can reduce sonic booms to a tiny fraction of what the Concorde generated.
Personally, I believe we may soon see an corporate jet SST seating
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Actually, Rolls-Royce spent a lot of time evolving the Olympus turbojet so it could run in full reheat for long periods of time--a feat that was thought to be almost impossible.
But we've come a long way in engine technology since then. The GE YF120 showed how much engine technology has evolved since the time of the Olympus Mk. 593; something similar could become available for the SST corporate jet I mentioned, especially since at a maximum of Mach 1.6 the engine may need very little reheat operation, which
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You are correct that supersonic flights will never be more economical - but that is only if you ignore time. Time is tricky to evaluate because everyone will have a different opinion on how valuable it is.
Ignoring the obvious error of mpg per passenger, this simple assessment does not differentiate between the different stages of flight. It matters because the majority of fuel is used at takeoff. Once at the desired velocity and altitude it takes considerably less fuel to maintain said velocity and al
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The actual fuel efficiency ratio is on the order 4:1, not 17:1. You have factored in the number of passengers twice, for some reason, creating the erroneous 17:1 ratio. Fuel cost can be off-set by an increase in the number of passengers, which in turn is enabled by the increase in the number of routes that can be flown, which is what this project is all about. The only routes that the Concorde could fly at Mach or above had to be over water, which limited the number of potential routes, which in turn sev
Copyright violation (Score:2)
Low-Flight (Score:2)
How low? The article wasn't clear on this.
HOW does this make it more economical? (Score:2)
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Concorde could only fly two or three routes because of the ban on flying supersonic over land, and even then it generally had to do some combination of flying a longer route that was more over water and flying subsonic at the beginning and end of the route. Flying subsonic in a supersonic aircraft drinks fuel and takes longer.
Longer flights mean less efficient utilization of the aircraft, more fuel is more fuel, and limited routes means the research and manufacturing costs are spread over fewer aircraft.
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The cows will be thrilled (Score:2)
...and maybe also deaf.