NASA Photo Captures Sound Barrier Being Broken (cnn.com) 28
NASA used specialized Schlieren photography to capture an image of Boom Supersonic's XB-1 demonstrator aircraft breaking the sound barrier on February 10, 2025 and producing shock waves as it exceeded Mach 1. The flight produced no audible sonic boom, marking progress toward the goal of quiet supersonic travel. CNN reports: "This image makes the invisible visible," said Blake Scholl, founder and CEO of Boom Supersonic, in a press release. In order to capture the Schlieren images, Boom chief test pilot Tristan "Geppetto" Brandenburg positioned XB-1 at an exact time in a precise location over the Mojave Desert.
As the aircraft flew in front of the sun, NASA's team documented the changing air speeds as speeds over Mach 1, the speed of sound (761.23 miles per hour or 1,225.1 kilometers per hour). The images were captured during ground telescopes with special filters that detect air distortions. You can view the photo here.
As the aircraft flew in front of the sun, NASA's team documented the changing air speeds as speeds over Mach 1, the speed of sound (761.23 miles per hour or 1,225.1 kilometers per hour). The images were captured during ground telescopes with special filters that detect air distortions. You can view the photo here.
Maybe I'm confused (Score:2)
Re:Maybe I'm confused (Score:5, Informative)
Re:Maybe I'm confused (Score:5, Interesting)
Historically, nobody really NEEDED to take a perfect photo of it. Did you hear the boom? Cool it must have happened. This aircraft is the only one making that kind of pressure differential that can't be measured by ground based seismic detectors.
Lots of photos of shockwaves exist, but none directly in line with the sun to get that level of primary light source. Virtually invisible in clear air with a blue background. Sure sometimes one can see a stationary vapor cloud due to pressure differentials but that isn't quite as useful after about 15 feet or so. Photographed against a terrain backdrop, naturally the gound would have a lot of variation as well as significantly lower light levels.
Honestly I think this is a good idea. Glad somebody thought of it.
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Re: Maybe I'm confused (Score:2)
Re: Maybe I'm confused (Score:1)
Not on a full-scale plane at speed. But you can take pretty pictures in the lab.
https://i.etsystatic.com/14054... [etsystatic.com]
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The main problem with them was they produce an audible sonic boom. Here we've got additional confirmation that, in fact, the sound barrier was broken, and there was no audible sonic boom from the ground.
The French and UK governments never did a proper analysis to determine if the concorde would be economically viable, so the whole thing just ended up being a public works project that never had a realistic chance of succeeding.
Re:Maybe I'm confused (Score:5, Informative)
Of course they did. How do you think they knew how to do this kind of photography? Scott Manley did a good video on it and showed the difference between the shock waves in a schlieren photograph of a conventional supersonic aircraft vs this prototype demonstrator. https://www.youtube.com/watch?... [youtube.com] The pictures he has our way cooler than the one in the article. Also explains why the sonic boom is quieter and doesn't always hit the ground with this special design.
Re:Maybe I'm confused (Score:4, Informative)
BOS (Background-Oriented Schlieren) wasn't invented until AFAIK 2015, and it's taken time to mature.
These are not the first BOS photos, but it is a new technique that postdates the Concord.
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The technique of taking in-flight Schlieren images comes from the work of Dr. Leonard Weinstein at NASA Langley Research Center back in the early 90's. The first image using this method was taken of a T-38 supersonic trainer in 1993 (https://www.dfrc.nasa.gov/Gallery/Photo/Schlieren/HTML/EC94-42528-1.html). Schlieren imaging, though, dates back to the 1800's (https://en.wikipedia.org/wiki/Schlieren_photography) and is a common flow visualization technique for supersonic wind tunnels. It allows one to see de
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I don't get it either. Here's NASA's on photo from 1993 that shows the exact same thing that these others are showing. A lot grainier and in black and white, but 1993.
https://acoustics.org/2apaa-th... [acoustics.org]
Is NASA just trying to keep their budget by saying they found something brand new? The new photos look like a different plane, higher res and a color filter.
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E=MC^2 would like to have a word with you.
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People talking about stuff they don't grasp.
Atrocious.
1864! (Score:2)
Schlieren photography was invented in 1864, photography itself was just getting started. Talk about being ahead of your time. Then again the general effect was observed before in early microscopes.
More on the topic (Score:5, Informative)
Having schleiern photography of the actual booms will be an important part of validating the computational models that Boom has been using in their design. Also: they look really cool!
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Thanks to NASA and the American taxpayer! Too bad this kind of stuff if now considered waste, fraud, and abuse - probably with a dose of DEI thrown in - and is likely to be summarily cancelled without any consideration.
Re: More on the topic (Score:2)
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You can "save" a lot of money by eliminating the "waste" of paying your mortgage.
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I'm not expert, but... (Score:3)
... as I understand the linked articles (I know, sacrilege to actually go read them), this test was to prove there was a supersonic boom (the photo) while nothing to be heard at ground level (acoustic sensors). The latter is made possible by software that calculates a flight path based on atmospheric conditions and speed, so that the sound waves refract before reaching ground.
This flight software (probably) has also enabled the precision flying to get the aircraft exactly between the sun and the camera - just my guess. I don't think we appreciate how incredibly fine that would have to be. Much less margin for error than the boom-less supersonic flight level.
No sonic boom seems to be a big deal, since its absence would make over-land supersonic flight possible. Which seems to be the big hurdle for an economic supersonic plane. I *guess* running a supersonic engine subsonically is not very efficient - a lot of changes to aerodynamics at the speed of sound. I'm sure the plane has also other improvements over previous supersonics, but that is less blingy attention grabbing than a photo.
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With few exceptions, all the engines of supersonic aircraft run subsonically. The incoming air gets slowed to subsonic speeds before hitting the first turbine stage. Sometimes this is accomplished by taking clever advantage of supersonic shockwaves forward of the engine intake (or the intake cowling itself).
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I would think they knew exactly what was going to happen based on computer simulations of the shock waves. However it seems somewhat useful to have this photograph to match the real world to the computer simulations, just in case they were wrong.