Nasa’s X-59 quiet supersonic aircraft begins taxi tests
nasa.gov126 points by rbanffy 3 days ago
126 points by rbanffy 3 days ago
The distance from front wheel to the end of the beak is impressive, its sooo engine-side heavy I guess. Curious if it requires a lot more tender landing procedure
The cockpit slightly in front of the nose wheel isn’t that unusual and the rest is just a very long nose cone added for the flow effect (that’s probably pretty empty and light).
In planes with tails, the center of gravity is always a little bit forward of the areodynamic center of the wing which is at approximately 25% from the front to the back of the wing. This arrangement is what allows the tail and the wing to balance each other.
It looks like the pilot barely sees out the window? Does it rely on cameras or does it föy by itself?
It relies on cameras.
Wikipedia: The flush cockpit means that the long and pointed nose-cone will obstruct all forward vision. The X-59 will use an enhanced flight vision system (EVS), consisting of a forward 4K camera with a 33° by 19° angle of view, which will compensate for the lack of forward visibility.
Thats pretty cool, Concorde had to drop the nose so the pilots could see out when landing, no longer an issue.
What happens if the camera stops working?
Same thing that happens when flying through storms or clouds - fly by instrument.
Regular aircraft equipped for IFR can't safely land with zero forward visibility. The pilot has to be able to see the runway for the final touchdown and roll out. Only a few aircraft and airports are able to do Category IIIC precision landings.
https://skybrary.aero/articles/instrument-landing-system-ils
In an emergency you do whatever you have to in order to preserve safety and lives.
No idea if the procedure here would be use a backup camera, try to land on ILS, or eject/bail out (if equipped). Presumably they've thought of that and it's in the "emergency procedures" section of the flight manual.
I am sorry for a stupid comment, but when I hear this I always picture sad pilot reaching for a guitar, playing a ballad and hoping for the best.
Are there many pilots who are even rated for 6-strings?
I know commercial airliners are required to carry an emergency ukulele, but that's only 4 strings.
Obligatory Airplane! (sorry) https://youtu.be/zUOB-BkSMa8?si=QPx8pwcqn_luNJuf
I knew what it was going to be before I clicked it, but I clicked it anyway. Classic.
Having only seen images of that plane on its side, I really didn't expect the beak to look like a duck.
I wonder how they manage the stability with that much aerodynamic surface out front.
Is any super sonic flight truly commercially viable/sustainable or is this just a skunkworks front?
Even if supersonic flight were 2.4x less fuel efficient than regular flights, based on Concorde vs other aircraft, if that translated into 2.4x ticket prices, a lot of people would still pay it.
$1000 vs $2400 to get to Europe in 6 hours instead of 12? A lot of people who just hate those long flights would pay for it, especially given that flights are only a portion of total vacation cost, together with hotels, etc.
Or for a flight inside the US, $1000 rather than $400, but to get from coast to coast in 3 hours rather than 6, may be very worth it for some people.
https://aviation.stackexchange.com/questions/107206/how-clos...
Worth mentioning that no one intends to make commercial jets go Concorde fast (mach 2) again, to my knowledge.
Boom is talking about "Boomless Cruise" being up to mach 1.3. they are trying to bounce the downward going sound waves off the atmosphere, bouncing them back up. It seems to be significantly speed dependent? https://boomsupersonic.com/press-release/boom-supersonic-ann...
What happens when there are 1000 flights over land all having sonic booms, and 1000 reflecting sonic booms, and the 1001 plane flies through all the sonic booms?
The concord was heavily subsidised. Those ticket prices didn’t cover the cost of the service.
It was also far less pleasant a ride than even most economy class tickets for long hall flights. The space was more cramped and it was much louder inside the cabin. Personally, Id rather spend more for nicer seats on a longer flight than worse seats on a shorter flight. And a lot of people with money felt the same.
Design changes might help with the passenger comfort problem but when the plane is already running at a loss, it’s a hard sell asking for more R&D costs (which would be massive) to redevelop the concord.
This is something I've really flipped on when I started taking trains more to replace domestic flights (in Europe) to improve my personal CO2 footprint.
I used to be really impatient with travel and tried my best to save travel time, and never took the train. Then I forced my self to change my ways.
Nowdays, I find thst plan the train travel days as part of the trip: Sure, it takes me a whole day to get somewhere, but I allocate that time for hacking on the laptop on a side project, reading a book, or playing a game on the Steam Deck, things I normally don't find that much time for. I find e.g. my vacation satisfaction actually has gone up.
Train travel is also easier with (my) kids than air travel despite the longer duration, because you can roam the train more, change location to the restaurant, etc.
Hard agree. If you lean into it, it's a much more pleasant way to travel in many cases.
Everything about air travel is rushed, stressful, and unpleasant. Yeah, I can get there in 3 hours (if you account for the "show up two hours early in case we understaffed the check-in desk" thing), but by the time I get there I'm _wiped_. Plus I'm probably going to end up either leaving or arriving at some ungodly hour that means my sleep schedule's screwed and that's basically all I'm getting done that day anyway.
The train I take instead runs every 30 minutes. You can rock up 6 minutes before the train leaves and walk right on after someone scans a QR code. You can bring a drink! There's tons of space for people and luggage. The seats are huge. Your legs fit. The tray is big enough to actually work on. You can get up and go for a walk. There's a water fountain and water bottle filler. The washroom is bigger than some bedrooms I've had.
If you're traveling with kids you can actually book seats at a full-fledged table and have lots of room for activities and colouring and such.
And it takes 5 hours. So sure, in theory it's two hours longer. In reality, I've got back almost 5 hours of my day. And I can arrive at a reasonable hour and not tired and stressed to shit and actually do things with the rest of my time.
Last trip I used the way there for some relaxing. Did some reading, played some games, generally just wound down. On the way back I was able to get some work done effectively so actually got paid for my travel day. Either way, it was a much better experience.
I'd do it 1/10_000th the speed if I could, from an airship with a hotel glued to the bottom.
An air-yacht sounds awesome, especially if it could be made really safe and comfortable, and fly low enough that you can see the views. You may not even want to get off the yacht at all!
> Or for a flight inside the US, $1000 rather than $400, but to get from coast to coast in 3 hours rather than 6, may be very worth it for some people.
Don't those people already have access to private jets?
Do you know how big the gulf is between a first class ticket and a private jet? Having more options between those two would reach a huge market, especially if it saved time instead of just offering “luxury.”
I assume anyone that can afford a first class that isn't having it paid for by a company can also afford a ride on a private plane. They just choose not to.
It depends how many people you bring on the private jet. Rich people usually come with quite the entourage. I'd imagine that becomes cheaper pretty quickly
It's not an incorrect statement, if for the flippant reason. To charter a jet, you pay for the jet in total not for individual ticket sales. So if you divide the jet's charter price by the number of people and each person chips in does become more feasible. Plus the amount of time you don't need to spend at airports waiting, going through security, waiting for baggage claim, etc. Private jets also fly faster than commercial, so there's an additional bit of time saving as well
The Concorde and what I understand to be it's lack of viability was exactly what I was thinking about - it motivated my question. What's different now?
They did fly them for 33 years. Even if it didn't work out in the end its not exactly an abject failure. I could imagine slightly better business plan, etc could make all the difference.
After all, concorde design started almost 75 years ago, surely we've learned a thing or two on how to design aircrafts with lower maintenance & operating costs in that time.
It lost money consistently all the time.
The only reason it kept flying for 33 years is a vanity project for national airlines.
Which it was excellent at. Actually viable business? Not so much.
> It lost money consistently all the time.
> The only reason it kept flying for 33 years is a vanity project for national airlines.
Something that loses money, but not so much money that it can't be justified as a vanity project, seems like the sort of thing that could be profitable with tweaks and improvements.
Like it didn't work, but it was close enough to working that reasonable investors could say: second time will be the charm. Especially given how much more mature aeroplane technology is now vs the 1950s.
To put it in perspective, we first broke the sound barrier in 1947. People started designing the concorde in 1954 only 7 years later. It is now three quarters of a century later. Technology has improved a lot since then.
Concorde made an operating profit. Not a huge one (how could it, with fourteen planes flying), and it didn’t recoup development costs, but it was in the green once that initial cost was paid.
Concorde never paid those initial costs, and had massive subsidies [https://www.nytimes.com/1981/01/09/business/france-extending...].
It was able to coast, eventually, but that’s some very fancy accounting.
“French Transport Minister Daniel Hoeffel, saying France ''will not and cannot abandon Concorde,'' signed a new agreement with Air France this week. The French Government, which with Britain had spent more than $2 billion developing the world's first supersonic passenger aircraft, will pay 90 percent of the plane's estimated operating losses for the next three years, compared with 70 percent in the past.
Under the new pact, the French taxpayer will contribute $66 million this year to the cost of Air France's champagne-and-caviar service linking Paris with New York, Washington, Caracas and Rio de Janeiro. In 1982, when losses are expected to decline slightly, the subsidy will be about $64 million, and in 1983, $59 million.”
In my opinion, there are worse ways for governments to subsidize aerospace and materials research and development, improve the connectivity between nations, generate national prestige, give people optimism for the future, and so on. 2 billion doesn't sound like a lot. It's a drop in the bucket compared to US military expenditures.
If California High Speed Rail loses a little bit of money, I won't be too upset by it. Unfortunately the up front costs are much higher, but at the same time, massive, massive infrastructure development is happening in California all along the length of the state, and the government is acquiring the rights to develop public transportation both now and into the future on that land. Again, there are worse ways to spend the money in my opinion.
I am not sure if there are much worse ways, as this here means normal people subsidizing rich peoples luxory fast flights.
Bad for climate. Bad for the people below enjoying the noise. Bad for all the other things you could do with 2 billion. (A lot)
Only good for people who want jetting quickly around the World.
And it is good for material research, but that's the same argument for military development.
Revenue exceeding ongoing costs after writing off development costs is not very fancy accounting.
I remember seeing something from Boom (now renamed?) which was an YN company years ago. I recall them developing some technology to solve the noise problem - somehow bouncing the sound off the atmosphere or similar IIRC? I do think its viability has increased over the years, just everyone has this default "it wont work" mindset because of the failure that was Concorde.
the biggest difference is that composites and better computers probably make designing and manufacturing a good design a lot more feasible
IIRC the big issue was cooling the air into the engines. I think that is still a big issue.
The engines remain really tough, but using a properly tapering fusalage does let you increase capacity/thrust by 10-20% (and a lighter airframe helps here too)
X-59 appears to be the only known active research demonstrator as XB-1 was retired.
Boom claims to have completed their Overture facilities and plans to unveil a completed aircraft this year.[0]
If the overland regulation changed, there would very likely be Supersonic business jets after a decade or too.
Boom the only company trying to seriously do it, and they are facing a major uphill battle and will need many billions more.
And this NASA project doesn't really solve the problem, because its primary way to avoid the noise, is to reduce what would be cabin space for the already limited space. So that makes commercial viability even worse.
14 CFR 91.817 was changed in the US, sort of, by executive order (depending on if this is legal) and by a proposed bill Supersonic Aviation Modernization Act (SAMA) H.R.3410
https://boomsupersonic.com/flyby/breaking-the-sound-barrier-...
I mean, the FAA changes regulations all the time without Congress (when people talk about regulators as a fourth branch of the government, this is what they mean). FAA is under the direction of the Executive Branch.
Reminder that NASA's X-59 (which tests redirecting shockwave mostly upwards) is different from Boom Airspace's XB-1 (which tests flying slower than speed of sound down on the surface)
Quiet supersonic taxiing is indeed impressive
Someone at NASA is trying to get some good PR going, this is barely a story.
They should use a Starship rather. Much quicker. The only hurdle would be the price.
> The only hurdle would be the price.
This is not the only hurdle. You can have an airport right next to a major city, with hundreds of arrivals and departures each day.
The same cannot be said for a Starship spaceport. Due to very loud launch, sonic booms on landing [0], and the danger of dropping a Starship onto populated areas, it would likely need to be offshore. That requires a boat, so now boarding a Starship involves thinking about sea states, taking a ferry ride on each side, and more.
Starship is super cool, but point to point Starship is a bit of a fantasy when you start to get to the nitty gritty.
[0] https://www.nasaspaceflight.com/2024/11/starships-sound-stud... (TL;DR: Super Heavy's sonic booms are 110 dB when standing 20 km from the booster.)
It could be possible for a couple routes where launch and final approaches could be done over water. It'd need some shallow seas, so platforms could be anchored to the bottom, as well as some high-speed rail and some veeeeery long rail bridges connecting the spaceport to land.
A quick look at ocean depth maps points to friendly continental platforms around the East US, China, a lot of Australia and New Zealand, and most of South America.
It'd be a massive effort, but not completely impossible. To get to Brazil to see my family, I'd probably need to first go to Southwest Ireland before boarding a suborbital flight to Rio, so it'd be 2 hours of rail, then 20 or so minutes of suborbital, then another hour flying to São Paulo (which is not on the coast). Still beats flying through Lisbon, Amsterdam or Paris.
110dB 20km from the origin? That is a serious WTF right there if that number is accurate. If my quick estimate is correct that would mean that the sonic boom is deadly to anything within a few 100m around the booster. Even 110dB is skirting the border to permanent hearing damage from a single exposure.
Both the Saturn V and the SLS produced over 200dB. Considering that the scale is logarithmic the sound must be quite literally staggering.
https://www.theoverview.org/p/sls-vs-saturn-v-which-was-loud...
Here's some noise data from Starship launches. This says that it emits over twice the acoustic energy of SLS at launch:
https://pubs.aip.org/asa/jel/article/5/2/023602/3337259/Star...
Hear, hear. Rapid dragon air-launched Superheavy with two-way radial symmetry switchblade wings for engine-forward horizontal landing. Make it a big-ass glider biplane with big Dragon in its tail for cargos. No sketchy flops or balancing act, Cg forward of CoL all the way from retro burn to touchdown. Capsule escape available down to 500 feet or there abouts.
> Starship involves thinking about sea states, taking a ferry ride on each side, and more.
Passengers could eject a few km above ground and parachute to their destination like Yuri Gagarin did on Vostok 1: https://en.wikipedia.org/wiki/Vostok_1#Reentry_and_landing
:) /s
>The only hurdle would be the price.
And that suborbital spaceflight is effectively off the table for anyone with a heart condition. There's a reason why you see all those warnings on rollercoasters even when the dangerous part lasts <1s. Now let's subject someone to minutes of it.
And the dying in a fireball. Starship’s design seems fundamentally impossible to make safe.
That's akin to saying that it seems fundamentally impossible to make landing rockets safe which, in fact, is exactly what Boeing/Lockheed were saying when SpaceX was first revolutionizing that space as well.
I’m not aware of any rocket landing safe enough for human use. NASA nixed the idea of propulsive landing for Dragon 2 for this reason. It’s extremely difficult to make safe, since just about any reasonable engine configuration means guaranteed death if a single engine fails at a critical moment. Compare with modern airliners where an engine can fail at any point in flight and the plane can land safely.
So yes, I agree, it is akin to saying that.
Just to be a little pedantic, humans have done propulsive landings before. The Apollo moon landings were done with a rocket-powered landing :P
> I’m not aware of any rocket landing safe enough for human use.
I’m pretty sure the Eagle has landed with humans on board.
Pretty much nothing about Apollo was safe, even by the relatively low standards of modern space travel.
> NASA nixed the idea of propulsive landing for Dragon 2 for this reason.
That is completely false. First of all, NASA didn't nix it, they just didn't make it a priority as it had little value from their perspective.
The reason it was not done is that para-shouts have to be in the design anyway for abort situations, so that was fixed.
So for SpaceX, the question was to likely delay the program, and take on a whole lot of extra engineering work that they were not actually getting paid for, remember fixed price contract.
They were only going to work on it if they really thought they needed it for something like Red Dragon. And then they could still add it later.
And one of the primary reason SpaceX thought that its to hard, is that they landing feet would have to have gone threw the heat shield. That would have made the whole heat-shield design massively more complex.
Some dude who runs SpaceX seems to think the reason was safety. https://x.com/elonmusk/status/1104509345922838528
He said it was the difficulty in proving the safety. There's an informative article here. [1]
NASA likes parachutes because they've always used parachutes. SpaceX likes retropulsive landings because Mars is their goal, and Mars' atmosphere isn't dense enough for parachutes. It's also safer for the crew in nominal operation and enables a much higher degree of rapid reuse, relative to NASA's traditional operation of taking a salt water bath in the ocean.
So they could go through the [very reasonable] extensive costs and testing involved in proving the safety of the retropulsive landings, or just go old school, strap a few parachutes on and work on getting crew to the ISS (which was the goal at the time). They chose the latter and with the plan of getting back to retropulsive landings later, which they also did. Parachutes remain the main landing mechanism for the Crew Dragon, but it now also has retropulsive landing capabilities to be used in case of a chute failure.
[1] - https://www.nasaspaceflight.com/2024/10/dragon-propulsive-la...
In what sense can it be called safe if you haven’t proven it?
They had repeated successful demos of it, but NASA kept adding on new requirements while implicitly signaling that they had no interest in approving the system, which would have made Boeing's lander look obsolete before it was ever finished. NASA's judgements are heavily influenced by external factors that make it quite difficult on outsiders, while enabling reckless behaviors for insiders.
For example NASA deemed the Boeing crew vessel safe after its pad abort test resulted in only 2 of 3 parachutes deploying and it suffering a propellant leak - all in beyond optimal conditions. They deemed it not only safe, but safe enough to completely skip the scheduled in-flight abort test. All of this is of course how you ended up with astronauts trapped on the ISS that had to be rescued by SpaceX.
For another contrast there after SpaceX did swap over to a simple parachute system, their pad-abort test went off flawlessly. NASA still required they do an in-flight abort. Granted, that's nothing to complain about, because that's exactly what NASA should do. But they also should have had Boeing completely redo their pad-abort test and damned sure do an in-flight abort as well. Safety culture at NASA is generally completely dysfunctional because of non-safety factors.
This is nothing new either. Both Space Shuttle disasters were 100% preventable, and not only in hindsight. Engineers brought up the exact causes of both explosions well before they happened, but the bureaucratic layer ignored them.