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NASA’s X-59 Quiet Supersonic Research Aircraft Cleared for Final Assembly
- JumpCrisscross 7y agoIs anyone else around the world working on quiet supersonic passenger jets?
- ghaff 7y agoBoom is one company working on supersonic passenger jets. Various others also pop up from time to time.
- starpilot 7y agoBoom is for real: https://www.linkedin.com/posts/boom-technology-inc%2E_avgeek-aviation-aerospace-activity-6613206751187730432-Fttx https://www.linkedin.com/posts/boom-technology-inc%2E_avgeek... Fun fact/rumor: in the early 2000s, Lockheed SW was rumored to have a mature design for a QSP bizjet that they were shopping around to hedge funds for funding into production, since Wall Street were avid customers of the Concorde. Cessna was also working on something that has probably been abandoned.
- utopian3 7y agoI’ll be super excited to have low-to-null-boom supersonic transcontinental flights! But if this becomes a passenger plane, what kind of fuel efficiency would that have? Are supersonic aircraft more or less efficient (oranges and apples I presume).
- dexen 7y ago>Are supersonic aircraft more or less efficient Surprisingly enough, supersonic planes have good fuel economy while supercruising - thanks to thin air at the high altitude, and speeds around Mach 2 ... 3 being good for turbojet engines. Expect worse taxiing, take-off and climb fuel economy, due to dense air and also suboptimal (high) angle of attack. This means supersonic planes are best suited for longer routes. Even the grandpa Concorde had good fuel economy in cruise, however it was overshadowed by atrocious fuel economy at low speeds, and the use of afterburners in transsonic region[1]. The designed but never built Concorde "B" would have notably better economy thanks to more advanced engines doing away with the afterburners. [1] https://www.quora.com/How-fuel-efficient-was-the-Concorde-compared-to-similar-sized-jets https://www.quora.com/How-fuel-efficient-was-the-Concorde-co...
- throwawayhhakdl 7y agoIs it accurate to say that high speed efficiency matters much more for any flight a supersonic jet would reasonably take
- baybal2 7y agoYes, because of the second point, it makes sense to build new runways just to accommodate SSTs outside of normal landing procedures to let SST land while gliding down from their cruising altitude. Concordes were wasting double digit of their fuel reserve while flying in the holding pattern if runways were not available for some reason.
- gsnedders 7y ago> Concordes were wasting double digit of their fuel reserve while flying in the holding pattern if runways were not available for some reason. Though note this was uncommon; they were typically cleared for a direct approach all the way from cruise to touchdown. Part of the reason why they rarely got put in the holding pattern was the fact that it would quickly turn into a low fuel emergency, and part was giving the SST preferential treatment.
- imglorp 7y agoThe taxi phase, at least, can be mitigated with an electric tug motor built into nose gear. Engines can be off or idle until needed. https://en.wikipedia.org/wiki/WheelTug https://en.wikipedia.org/wiki/WheelTug
- jobseeker990 7y agoGreat point. Or motors in the rear wheels could probably get it up to 100MPH on the runway before the jets had to take over.
- DuskStar 7y agoI'm not sure if those fuel savings would be worth getting rid of the integrated pre-takeoff engine thrust test, though.
- Robotbeat 7y agoFundamentally, about half as efficient. You can compensate by cramming in seats closer or trying exotic designs. And there's some efficiency buy-back by operating at higher altitudes where the engine can expand to lower pressures (and thus increase the pressure ratio), but overall, roughly half as efficient is a decent guesstimate. Then again, conventional aircraft are about double the efficiency they used to be, so supersonic aircraft today could conceivably be approximately the same efficiency as transonic aircraft of yesteryear. I think exotic designs could enable decent range low supersonic electric flight (i.e. Mach 1.5 or something). Going to need good batteries, though, and extremely high aspect ratio wings.
- blackflame 7y agoA lot of the fuel efficiency of modern aircraft comes from having giant turbofans instead of turbojets. By attaching a giant fan the front of your compressor and redirecting most of the air around the engine you can get great efficiency at subsonic speeds. However, the nature of the fan has fundamental limitations when approaching the speed of sound and turbo/ram jets are basically just pouring gas in a tube of precompressed air.
- baybal2 7y agoI'm very impressed that they managed to keep it going for so long. It will be good to dispel the ideological status quo in aeronautics community that "SST is dead and buried"
- ghaff 7y agoI'm not sure there's a "dead" status quo around technical feasibility so much as there's a great deal of skepticism about economically viable commercial supersonic passenger air travel. (At least, possibly, beyond a niche for the very wealthy.)
- baybal2 7y agoSee, building aircraft is not so really that expensive. First supersonic aircrafts were built with manufacturing equipment which will not sell even on a liquidation sale today. Military jet bombers, while expensive by all measures, did cost less in the mid-20th century than equivalently sized airliners today. A lot of cost increase since eighties in the industry was due to increasing regulatory lockdown and decrease in efficiency due to decrease in competition. The $100 per piece "aerospace grade" nuts and bolts is exactly what I am talking about.
- starpilot 7y agoYou seem to know a lot of things. Do you have like a newsletter I could subscribe to?
- baybal2 7y agoI'm not really into aircraft engineering. I had a dip in it when I was really into drones in my high school years, and then tried myself at motogliders. For as long as engineering goes, I'm more into electronics and process.
- AWildC182 7y agoThis is a very good observation, though I'd make one nitpick... The tooling used for the airframes then isn't much different than the tooling used to build them now. The industry has only just started to embrace robotic composite construction, otherwise it's the same rivet guns and squeezers that they've always used more or less. If you know of any liquidation sales giving away 100s of clecos or dies for nothing, let me know...
- api 7y agoLooks like its landing on Tattoine, which is appropriate for that thing.
- jacquesm 7y agoIt says 'illustration' in the caption that's probably not a real image especially not given the article title.
- 0xffff2 7y agoIt's almost certainly a render of the plane landing at Armstrong Flight Research Center (longstanding home to the NASA X planes), which does in fact bear a striking resemblance to Tattoine.
- homonculus1 7y agoTunisia looks a lot like Tatooine too!
- CRUDite 7y agoApart from the Aerion as2 i dont think there are many other credible supersonic aircraft in development other than the Nasa one. Concorde, other than the booms, had engines so loud, and i mean insanely loud they would not be popular these days. I remember covering my ears as it flew overhead. I do find Elon Musks frequent mentions of a vtol ss aircraft quite interesting. Electric engines would not have the same issues at high altitude as conventional ones. Battery density is starting to get in the right area to make this feasible. He is frequently distainful of flying cars but one logical conclusion of this is indeed potentially flying cars (Tesla secret projects anyone?). When you think about how much of the world is inaccessible, one of these would make a great thunderbirds style exploration vehicle ( provided it had a large expandible solar array stowed somehow) . Fancy a trip to the Kamchatka ground zero? No problem! I wonder whether aerodynamically they would not need to be so concorde like and maybe just bullet shaped. Perhaps on Mars you could have supersonic blimps
- dmitrygr 7y ago> Electric engines would not have the same issues at high altitude as conventional ones Some of them they still do. Their air is still less dense, so if you force the same volume out per second, you generate less thrust anyways cause there is less mass per volume (and thus less thrust for you)
- nickparker 7y agoBuoyant forces in the Martian atmosphere would be teeny tiny no? I don’t think blimps would work very well. You could maybe get some sort of inflatable lifting body to work at high speeds though.
- TremendousJudge 7y agoAn advantage you have is that you can fill them with hydrogen and be fine, since there's no oxygen to allow them to suddenly combust
- mjevans 7y ago
- The_rationalist 7y agoHow many seats?
- cheeko1234 7y agoThis is an experiment rather than a finished product: The X-59 will never carry passengers, but it will likely kick off a new generation of quiet supersonic commercial planes that can fly over land and dramatically reduce the time it takes to get you across the U.S. and to other countries. https://www.nasa.gov/nasa-x59-quesst-takes-shape https://www.nasa.gov/nasa-x59-quesst-takes-shape The Quesst is an experiment to see if the annoyingness of the boom can be mitigated by converting the boom into a "thump" (i.e. quieter boom). Src: I work there
- The_rationalist 7y agoAs for the boom, why don't they just wait to be in very high altitude or to be at a place where there's almost no human in the surroundings?
- DoofusOfDeath 7y agoPerhaps I'm in the minority, but I'm concerned that commercial-supersonic will be a net-negative in my life. I'm assuming that, as with the Concords, most of the benefit for supersonic travel would be to very wealthy individuals and corporations. But everybody living/working beneath the flight path would have to endure the added noise pollution.
- dmitrygr 7y agoAlmost all new consumer-accessible technologies benefit the wealthy first, simply due to the initially-high costs. Just imagine if people like you had decision making power. We'd not have microwaves, televisions, cell phones, etc...
- ocdtrekkie 7y agoThe entire point of this concept is removing that noise pollution. Additionally, a more modern, efficient aircraft than the Concorde might conceivably someday make sense for more widespread, and hence more affordable use.
- DoofusOfDeath 7y ago> The entire point of this concept is removing that noise pollution. My understanding was that the noise-reduction was specifically for sonic booms. If I understand correctly, commercializing this would mean a transition from no sonic booms to quieter-than-before sonic booms. From my own, personal perspective that's a net-negative.
- ocdtrekkie 7y agoSpeaking as someone who used to live pretty close to an airport, I'd point out that normal airliners are not without noise pollution, and I'd rather it be gone sooner rather than later. The faster a plane crosses the horizon, the less of your time will have noise pollution. Then the question becomes how much quieter these sonic booms are, and how they compare to more traditional airliners' noise pollution.
- gertrunde 7y ago+1 for the googly eyes and mustache on the forward bulkhead... (dunno if that's what it's called, it was the name that sort of felt most right)
- moioci 7y agoAre you referring to the skunk on the nose cone just forward of the canard? I assume that's an indicator of a skunkworks project.
- homonculus1 7y agoA bulkhead is a wall inside a ship. The main structure of an aircraft is called the fuselage and the outer surface is the skin.
- etrautmann 7y agoThe attached image of the assembly has a nice easter egg: https://imgur.com/a/df6XnAs https://imgur.com/a/df6XnAs