The last time anyone other than a fighter pilot went supersonic was 20 years ago. Today, you can only visit a Concorde in a handful of museums. It's a relic, left behind by an industry that invested in efficiency rather than speed.
Now, companies are investing billions of dollars in restoring commercial Mach-speed flight, but the path to supersonic travel isn't going to be easy. Business Insider's Daniel Allen looks at the key reasons that bringing back supersonic is almost impossible.
Now, companies are investing billions of dollars in restoring commercial Mach-speed flight, but the path to supersonic travel isn't going to be easy. Business Insider's Daniel Allen looks at the key reasons that bringing back supersonic is almost impossible.
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00:00The last time anybody besides a fighter pilot was able to hit Mach speed was in one of these.
00:09But that was 20 years ago.
00:11The Concorde didn't just hit Mach speed, it went double the speed of sound, flying
00:15from New York to London in under three hours.
00:19Today you can only go visit a Concorde in a handful of museums.
00:23It's a relic, left behind by an industry that invested in efficiency rather than speed.
00:29Look online and you'll see that there's a huge appetite for supersonic travel.
00:34The race to supersonic is heating up.
00:37I've talked to nearly all the companies building these new planes, and I asked them,
00:41why is it so hard to bring back supersonic?
00:44And what's the limit to how fast a passenger plane can actually go?
00:50In order to understand the challenges that they're up against, I decided to start here
00:54at the Concorde.
01:00So my first impression of the plane is that the head clearance walking in is extremely low.
01:05I'm 6'4", and I have to really uncomfortably duck down just to get in this doorway.
01:10So we're going to see what it's like inside, but it's obvious that this plane's dimensions
01:15are totally different from normal commercial airlines.
01:18First of all, the head clearance in here, thank God, is a little bit better.
01:23But I am about touching, if I stand up straight, my head is touching here.
01:27So it is pretty narrow and low.
01:30Here's my hand against the window.
01:32Look at how small it is.
01:33When this plane was flying at such a high altitude, if there was a failure of one of
01:38the windows, these small windows were meant to slow that cabin depressurization.
01:43So it was a safety measure.
01:44And actually, on some of the newer planes that we're talking about, they don't even
01:48have windows.
01:49Attention Concorde passengers, on today's menu, Duck L'Orange, caviar, and champagne.
01:57Lots of champagne.
01:58I always wanted to hold one of these.
02:00Anyway, one of the things about the Concorde, it wasn't just about speed.
02:04It was about luxury.
02:06Every seat on this plane was considered first class, and the service was first class.
02:12There was a culture created on this plane of frequent flyers.
02:16A lot of the time, celebrities were getting invited to the front, to the cockpit.
02:21And the pilots that we talked to have some really fond memories of meeting those people,
02:26interacting with them, and almost creating friendships with them.
02:30The rock stars of that era, you know, the Rolling Stones, the Beatles, they would use
02:35it quite a lot.
02:37And they'd certainly be there.
02:38And I certainly remember them.
02:39And I had a menu where I was collecting my favorite rock stars' signatures.
02:46I sent it back to somebody.
02:47I won't mention the name.
02:48I sent it back to somebody for that person to sign.
02:51And they thought it was a gift for them, as it was their birthday.
02:54And they walked off with it, which was a bit of a blow, to put it mildly.
02:59This is the forward-most cabin before we get to the front of the plane and the cockpit.
03:04And I'm comfortably standing up now, finally.
03:06So that might be explained by the fact that, as you can see, the body of the plane gets
03:10sort of narrower towards the back.
03:13So we're in the front of the plane.
03:15We're towards the cockpit.
03:16The view is extremely narrow.
03:18If this was a car, I would not feel comfortable driving this on the road, because the visibility
03:24down to the ground is extremely poor, hence the droop snout design.
03:29So the Concorde's droop snoot was a feature that allowed pilots to see the runway during
03:35takeoff and landing, but then snap back into place when it was hitting supersonic speeds
03:39over the Atlantic Ocean.
03:42The beginning of the end for Concorde came in 2000.
03:45After about 30 years of service, tragedy struck.
03:50So we're underneath the plane now, and you can see the landing gear on each side.
03:55And one of the things that's understood about when the plane actually did crash is that
04:01there was one of the tires hit something on the runway, and it kicked up the piece of
04:07debris into the jet fuel tanks, which are right here.
04:11And that's what caused the fire that caused the eventual crash.
04:16Concorde did start flying again not long after, but its fate seemed sealed.
04:21And the last flight was a few years later, on the 26th of November, 2003.
04:25So over 20 years later, have any of these companies solved the big problems that Concorde
04:30faced while it was flying?
04:32Probably the most challenging obstacle these planes will have to overcome is their noise.
04:37The sound of a sonic boom has remained the biggest obstacle to supersonic flight since
04:41the very beginning.
04:46So far, 7,000 people have complained to the Ministry of Technology and to the Noise Abatement
04:51Society.
04:52Only one man has seemed to have come out in direct praise of the boom, and that's a 74-year-old
04:57old-age pensioner who claims that the boom has cured him of his deafness.
05:05We got a purpose to stop the Concorde.
05:08In 1973, following a public outcry, the U.S. banned overland flights for supersonic jets,
05:15followed by most other countries.
05:17That's why the Concorde was only ever allowed to fly supersonic over water.
05:21Planes have been getting quieter over the past 50 years, too.
05:25That's thanks to improvements in aircraft design and more stringent government regulations
05:29on sound.
05:31So a loudly booming supersonic jet would be even more noticeable compared to modern subsonic
05:36travel.
05:38So how does a sonic boom actually work?
05:40Here's what happens when anything travels faster than the speed of sound.
05:44So, sound is a wave of pressure.
05:46For a stationary object, it travels in concentric circles out from where the object is.
05:51The waves of sound get pressed up against each other.
05:54And that wall of high pressure?
05:56That is the sound barrier.
05:58Breaking that barrier means an object is traveling faster than the sound it makes.
06:02It leaves behind a loud shockwave, kind of like the wake behind a boat that's going really
06:06fast.
06:07And that is what you call a sonic boom.
06:09If a plane booms too close to the ground, it can actually shatter glass.
06:22Many people, including myself before making this video, thought that a plane booms one
06:27time when it breaks the sound barrier, and then it's quiet as it's moving through
06:30the air.
06:31That's actually not what happens.
06:33As long as a plane is traveling faster than the speed of sound, it's leaving that sonic
06:38boom sound behind.
06:40For every thousand feet of altitude, the boom carpet left behind the plane is about a mile
06:45wide.
06:46So, a plane traveling past Mach speed at 60,000 feet has a 60-mile-wide swath of land underneath
06:52it that's hearing that boom boom sound wherever it goes.
06:57And for those on the ground, that boom is about 105 decibels.
07:01That's at least twice as loud as a normal plane flying overhead, and it's equivalent
07:05to standing next to a chainsaw or a car horn.
07:10So let's look at our four planes.
07:12It's worth noting that I originally spoke to five key players, but one of them went
07:16under while we were making this video.
07:18And it just goes to show you how much of a challenge developing these planes can be.
07:23Each of them has completely different approaches to supersonic travel, and each faces different
07:28challenges.
07:29The X-59, Boom, and Concorde all use similar technologies, flying at 60,000 feet and hitting
07:36between Mach 1.4 and Mach 2.
07:39Those kinds of speeds can get you from New York to London in three hours, rather than
07:43the usual seven.
07:45The Halcyon will use a ramjet engine along the turbofan to get it all the way up to Mach
07:495.
07:51That would get you from New York to London in just an hour and a half.
07:54And the Stargazer is using a detonation rocket engine, something you don't commonly see outside
08:00of missiles.
08:01That might just do the same trip from New York to London in under one hour.
08:06So how are these four planes going to tackle the noise issue?
08:10Boom's Overture isn't looking to reduce the sonic boom at all at Mach 1.7.
08:15With Overture 1, we're starting really simple.
08:17We're putting sonic booms out over open ocean where no one's there to hear them.
08:22U.S. regulations still ban all commercial planes from going supersonic over land.
08:27But researchers at MIT found that 78% of demand for supersonic transport was over land routes.
08:34Almost 40% of that was on U.S. domestic flights.
08:38If these regulations change, Boom says the Overture could achieve a boomless cruise,
08:44flying at just over the speed of sound over land without an audible sonic boom.
08:49But this phenomenon requires specific atmospheric conditions to achieve.
08:54Flying any faster than that, without making a lot of noise, requires some really innovative
08:59design.
09:00And that's where the X-59 comes in.
09:02The X-59 isn't aiming for commercial supersonic flight like the others.
09:07It's actually one of 66 X-planes developed by the U.S. government.
09:11The X is for experimental.
09:13The first X-plane was the Bell X-1, which was the first plane to break the sound barrier
09:18in 1947.
09:20The X-13 tested vertical takeoff and landing.
09:23The X-15 was the fastest piloted aircraft that never left Earth's atmosphere, and it
09:28hit Mach 6.7.
09:31It's taken NASA and Lockheed six years to build a prototype X-59.
09:37First off, X-59's engine is on the top, not underneath the wings.
09:41So by putting the engine on top, we kind of shield that shockwave from reaching the ground.
09:47Then there's the nose.
09:48It's a little hard to miss, as it's 38 feet long.
09:52The idea of minimizing the sonic boom is to keep those shockwaves small, weak, and relatively
09:59evenly spaced.
10:01So that long nose essentially starts that process.
10:04It sets up those initial shockwaves to be weak and kind of equally spaced along the
10:09first part of the airplane.
10:11And lastly, the light carbon fiber further helps to reduce the plane's weight.
10:16Otherwise, the X-59 is built from parts of other planes.
10:19It's got a T-38 cockpit, which is a favorite for test pilots, and landing gear from an F-16.
10:25So, did NASA actually figure out how to quiet the boom?
10:29We feel that we have.
10:30I mean, we have shown in a wind tunnel, in an experiment and analysis, that an airplane
10:39can be shaped so that instead of producing a boom, it produces a thump.
10:44Their aim is to reduce the boom from 105 to 75 perceived decibels.
10:51That's equivalent to either a car door closing across the street, or the sound of distant
10:56thunder.
10:57As part of the Quiet Supersonic mission, NASA has exposed communities to a simulated sonic
11:02thump.
11:04In 2018, they conducted one of these surveys in Galveston, Texas, with 500 civilian volunteers.
11:19Eventually, the actual X-59 will make about 60 flights over a variety of yet-to-be-named
11:24communities in the U.S. to collect more data.
11:27But there's another, much simpler way to reduce the sonic boom.
11:31Fly higher.
11:32Both the Stargazer and the Halcyon want to fly much faster, and much higher, than the
11:36other supersonic planes.
11:38It turns out, at roughly about 100,000 feet, a sonic boom about 100,000 feet is inaudible
11:47to the human ear.
11:49We can measure it with scientific instruments, but it's inaudible to the human.
11:53That's Dr. Andrew Duggleby, the CTO and co-founder of Venus Aerospace.
11:57Just flying higher sounds like the easy solution, but when you're at those kinds of altitudes,
12:02a whole host of other problems quickly appear.
12:05So right here on this chart, at 26,000 feet, is the death zone.
12:09That's where the air becomes too thin to breathe.
12:11It's why most climbers need oxygen to summit Everest.
12:15Almost all planes cruise higher than this.
12:17But the higher the altitude, the bigger the risk when something goes wrong.
12:21When you're flying at 100,000 feet, if you lose cabin pressure and you don't manage
12:26it appropriately quickly, your blood will boil.
12:31Oh my god.
12:32So you basically have to treat it like a spacecraft cabin?
12:34Yes.
12:35Airtight.
12:36Yeah.
12:37But I think the solution that you see at the end of the day will look much more like a
12:41hybrid between a spacecraft cabin and an aircraft cabin today than just a pure aircraft cabin.
12:45For high-altitude military planes like the SR-71, the pilots actually had to wear sort
12:50of a modified spacesuit because of the danger of the altitude and speed that they were flying.
12:55Are CEOs going to want a spacesuit up to get to their meeting in Tokyo a little earlier?
12:59I'm not so sure about that.
13:02To be in a plane like this, there are so many things that could go wrong at a high altitude
13:07that you really need to protect your body from a worst-case scenario.
13:10And it's not just the pressure at high altitudes.
13:13There's one more problem with flying that high and that fast.
13:18You'll notice on this part of the wing, there's some black heat shielding.
13:22And the reason for that is that certain parts of this plane would be exposed to the most
13:26amount of friction at speed.
13:28The heat that could be experienced on the outside of this plane could sometimes top
13:32250 degrees Fahrenheit, combined with the fact that the exterior temperature was well
13:36below zero at the high altitude, negative 75.
13:40That heat and cold caused a lot of stress on the outside of the plane.
13:44It meant that it needed a lot of maintenance, and it meant that it was a limit to how fast
13:49this plane could go.
13:50Going faster than Mach 2, Mach 3, Mach 4, Mach 5, you need to get into exotic materials.
13:55Aluminum, like this plane is made out of, just doesn't cut it anymore.
13:59It's when you get really fast that heat becomes the biggest problem.
14:03Aerodynamic heating increases non-linearly with speed.
14:07That means that as speed increases, the temperature rise becomes more dramatic.
14:11What hypersonic really meant is the speed at which, pardon my French, it's the speed
14:15at which heat kicks your ass.
14:18It's where heat becomes the defining problem.
14:22If you're trying to go make a missile, sure, maybe you want to go hypersonic because you
14:26have other reasons to go really, really fast to avoid defenses.
14:29There might be military reasons to go crazy, blazing, fast, hot, but I bet if I look at
14:36this from a, I want to sell commercial flights, how do I keep the cost down and competitive?
14:40I bet I don't want to fly a Mach 5.
14:43One of the centerpieces of this museum is obviously the SR-71 Blackbird.
14:48You can see on the tail fin here, there's the symbol of Skunk Works, which are the people
14:53from Lockheed Martin, their sort of top secret division that works on stuff like this.
14:58This plane broke speed records going over Mach 3.
15:01It's one of the fastest aircraft of all time, and everything about it is built for high
15:06speed and to deal with heat.
15:09The SR-71 actually reached 600 degrees at Mach 3.2, and the glass in the cockpit here
15:16was actually an inch and a quarter thick quartz material.
15:20If you were to touch that, even with gloves on, you would burn your hand.
15:25So underneath the plane, the tires, again, because of the heat and the speed that it
15:29was traveling, these tires actually have inside of them nitrogen, not oxygen.
15:34The oxygen would just blow up at the speeds that this was going and the temperature it
15:38was hitting.
15:39And they also have a silver look to them because they contain aluminum, again, to deal with
15:43high heat that the plane was experiencing.
15:47The only way the fuselage could survive these temperatures was to make the entire thing
15:51out of titanium alloy, which is 10 times more expensive than aluminum.
15:56It's important to note that things that go into space and re-enter hit Mach speeds that
16:00are a completely different class.
16:03This thing would re-enter the atmosphere somewhere between Mach 16 and Mach 20.
16:08And that's why we always see on the space shuttles this black heat shielding on the
16:13front.
16:14That's actually reinforced carbon.
16:16As it's re-entering the atmosphere, it's exposed to heat that's on a different order of magnitude
16:21than anything that's flying, you know, at 100,000 or even 180,000 feet.
16:26But even though these hypersonic planes aren't going to be hitting space shuttle speeds,
16:30finding solutions to these problems is going to take time and money.
16:38The Overture has been in development for 10 years at this point, and Boom's test plane
16:45just broke the sound barrier in late January 2025.
16:48There we are.
16:50XB-1 is supersonic, faster than the speed of sound.
16:54The X-59 is expected to take its first flight in 2025 and has already cost $632 million.
17:02That sounds like a lot, but building a plane is never cheap.
17:06Both the Airbus A380 and Boeing 787 Dreamliner cost over $20 billion to develop, and that's
17:13with huge manufacturing arms already in place.
17:16The CEO of Boeing said if they were to develop a new plane today, it would cost $50 billion.
17:24Exosonic was going to be the fifth plane on our list.
17:26They were also aiming for a very achievable sounding Mach 1.8 plane using already existing
17:32engine technology.
17:33They closed their doors completely in November 2024.
17:37I spoke with the CEO before they went under, and he was a little more realistic about timeframes
17:41for this technology.
17:43So at least for the airliner, we don't see that coming into the market until like mid
17:47to late 2030s, which I think, you know, UBS or some other bank had a similar conclusion.
17:55The speed of developing these planes isn't helped by the fact that there's literally
17:59only one place you can fly supersonic planes over land in the United States, the Edwards
18:04Air Force Base.
18:07We can take off and immediately climb up to 30,000 feet where we're now cleared to go
18:11supersonic and that doesn't exist basically anywhere else in the country and certainly
18:15probably not even around the world.
18:16Edwards Air Force Base was established around two dry lake beds.
18:20It's roughly 35-ish square miles of naturally dry, compacted surface that's hard enough
18:27to land airplanes on.
18:28There are other areas, especially over the water, where you can be doing supersonic flight
18:32tests, but that's not exactly a place you want to be if something goes wrong during
18:37the flight test.
18:38I don't want to be over the water and I certainly don't want to be far away from a landable
18:41surface.
18:42But the area is not completely uninhabited.
18:45We asked a few people in nearby towns what a sonic boom sounds like.
18:49I've heard it described as the sound of freedom.
18:52Well, sometimes you get the rumbling, the building will shake, and other times it's
18:56just a loud like MAD or something going off, a big explosion.
19:01So when people come here and not from the area, they hear the noise and the first thing
19:04they want to do is run out the store because they think it's an earthquake.
19:08So to me it's funny and I just look at the reaction and then let them know it's a sonic
19:12boom.
19:13So, NASA, Lockheed Martin, Boom, Hermes, and other organizations building supersonic prototypes
19:19will at some point be testing in this one strip of land in California.
19:23And it's not just the test flights.
19:25Finding the space to test engines is even more of a challenge.
19:29But that's changing.
19:30And we went to Jacksonville, Florida, to check out why.
19:33This is Cecil Airport, it's outside Jacksonville.
19:37We're here for a press event.
19:38So basically Hermes is opening up a new facility here that's called HEAT and it's going to
19:45be for testing engines.
19:48And they've got their quarter horse prototype plane inside the hangar here, so we're going
19:54to get to check that out, which is pretty cool.
19:56Let's go take a look at this plane, wow, this looks crazy, look at this.
20:02So in order to test the engines associated with hypersonic flight, there's only a couple
20:07places in the country that you can do it at the scale that we need, at the scale of the
20:10F-100.
20:11And that primarily, the kind of like go-to one is Arnold Engineering Development Complex.
20:16That facility is bottlenecked in the entire country because everyone wants to get in there.
20:21And so what we want to do is not only bring in something that will help us accelerate
20:25our roadmap that isn't bottlenecked where everyone is trying to get there, but also
20:29increase the capability of the country.
20:31So this is the tunnel, this is the inside of the tunnel where they're going to be testing
20:35things like the quarter horse and other engines.
20:39And it's hard to tell, but it's super, super quiet.
20:44Hermes, an Atlanta-based firm, is arguably the furthest along in testing their hypersonic
20:49prototypes.
20:50They're planning to modify the Pratt & Whitney F-100.
20:54That's the same engine that's inside an F-16.
20:56So what they're doing is cocooning that engine inside of proprietary technology to take what
21:01was an engine that could go Mach 2 and giving it the capability to go Mach 4, 5, and above.
21:08You spend a lot of time in Washington.
21:09I do.
21:10And that means you're probably talking to people from the Department of Defense.
21:14The systems you see the department investing in right now are one-way systems, right?
21:18You send them, they launch, and then they don't return.
21:21And so every time you-
21:22AKA missiles.
21:23Missiles.
21:24$20 million a shot or more.
21:27And so the cost is really challenging to scale.
21:29When you have a vehicle that returns, the cost per effect of those munitions significantly
21:34decreases.
21:35It would also have the impact of unlocking a lot of private capital.
21:39Hypersonic weapons are at the center of an arms race among the world's superpowers.
21:43That's because a hypersonic missile remains within the Earth's atmosphere, unlike an ICBM,
21:48which goes up in a sort of parabola and then comes back down.
21:52In theory, it makes hypersonic missiles harder to detect.
21:55The U.S. has spent over $10 billion on hypersonic weapons so far, about 3% of the overall R&D
22:02budget for defense.
22:03And it seems to be with good reason.
22:06China may have already tested a hypersonic nuclear weapon.
22:10And they've built wind tunnels that can test speeds up to Mach 30.
22:14According to articles we've read, Chinese scientists have patented an engine that can
22:18go up to Mach 16.
22:20And one Chinese company, called Space Transportation, is building what they call a rocket with wings.
22:26Take a look at this wild CGI video.
22:31Do you think that the United States is behind on hypersonic?
22:35I think it's an incredibly difficult competition.
22:37We have a different approach in general to how China and Russia have taken it.
22:42I mean, the flight tests kind of speak for themselves.
22:45The pace of flight testing that China, the CCP, have been able to demonstrate over the
22:50past decade exceeds ours by an order of magnitude.
22:54And I think that speaks for itself.
22:56So I guess the last question is, when will you feel like hypersonic passenger planes
23:02are a real thing?
23:04Ask me again once we've flown a hypersonic aircraft.
23:07That's step one that we've got to prove out.
23:10So we know it's going to take a long time before supersonic or even hypersonic passenger
23:14planes are going to be in the air.
23:16And development is going to take a lot of investment, another problem that Concorde
23:21just didn't have.
23:23The development of the Concorde was completely subsidized by the governments of France and
23:27the United Kingdom.
23:28Rolls-Royce, the engine manufacturer, was actually government-owned during the Concorde
23:32era because it had filed for bankruptcy.
23:36The airlines didn't even have to buy the planes.
23:38I mean, initially, let's face it, the airplane was basically given to British Airways.
23:41I mean, they didn't have to pay a cent for it.
23:44That level of state investment just isn't happening today.
23:48And that's definitely going to slow development.
23:50I wouldn't be surprised if we saw a commercial supersonic around 2050.
23:56And to kind of unpack that, we would need to have both low-boom aircraft and very abundant,
24:03very cheap SAFs in order for supersonics to succeed.
24:07And 2050 is about the timeframe that I think it could happen.
24:11That's Dan Rutherford.
24:12He's an environmental engineer that's been researching aviation emissions and policy
24:16for about 15 years.
24:18SAF stands for Sustainable Aviation Fuel.
24:22It's still an emerging technology, but it's one that's going to play a crucial role when
24:25it comes to these planes because of just how much fuel they need.
24:32Let's compare fuel use against standard subsonic airline travel.
24:36Commercial planes vary, but take the two most common planes flying today, the Boeing 737
24:41and the Airbus A320.
24:42Now, this, of course, varies on route, weight, and lots of other factors.
24:47But as a fairly high estimate, they both use around three tons of fuel per hour.
24:52Now compare that to the Concorde, which used a massive 22.6 tons per hour and for a lot
24:58fewer passengers.
24:59Even if you were to calculate it per distance, Concorde gets 13.48 miles per gallon to a
25:05777's 80.
25:07Now it's obvious that jet fuel is different from petrol.
25:10It's actually closer to diesel.
25:12But for a simple comparison, a full flight on Concorde is the emissions equivalent of
25:16every passenger on board driving from London to New York in a Ferrari 812 Competizione.
25:22And not only is it burning more fuel, but even the same amount of fuel use could be
25:26worse for the environment at higher altitudes too.
25:29Because supersonics would fly very, very high in the sky, there's a concern that emissions
25:35from their engines will have a disproportionate impact, especially on the climate.
25:40And just kind of ballpark figure, if a plane is operating at, say, 33,000 feet, emissions
25:48from its engine stays in the atmosphere for like two or three days.
25:53But if you take it and you make it supersonic and you fly it 55,000 feet, what we call the
25:59residence time, or the amount of time that pollution stays in the atmosphere, is more
26:03like two or three years.
26:06And that's very concerning both from climate change and then for ozone depletion.
26:10How are these newer planes going to solve this efficiency problem?
26:13Well, the truth is they really aren't.
26:16The main problem is the faster you go, the less efficient travel becomes.
26:21In fact, Saudi Arabia wants to invest in supersonics precisely because of this.
26:26They highlighted the future of supersonic flight as a key focus in their oil sustainability program.
26:32Here's a graph showing the drop-off in efficiency at greater speeds.
26:36The higher up on the graph, the more efficient the plane.
26:39Boom is probably the closest of these projects to reality, and they claim that the Overture
26:44is 30% more fuel efficient than Concorde.
26:47Maybe moving them up here.
26:49The Halcyon will be using a ramjet and end up somewhere around here on the graph, just
26:53beyond the SR-71.
26:56The Stargazer uses a similar engine, but also adds their brand new rotating detonation rocket
27:01engine for higher speeds.
27:04Rockets are way more inefficient, and if you look at the bottom of the chart, that's where
27:08you're going to see the rocket propulsion.
27:10Not a lot of planes use rocket propulsion for that reason.
27:13Compared to the Concorde's 22 tons of fuel per hour, this thing burned 20 tons of fuel
27:19per second.
27:22Now it's not an exact comparison, obviously, because the planes that we're talking about
27:27are not launching directly up to get out of Earth's gravity well, but it just gives you
27:32an idea of how much fuel it takes to move weight, you know, up into the atmosphere.
27:38I mean, you could kind of see the design is different, right?
27:42They're more compact.
27:44It's just about throwing as much power through it as you can.
27:49Venus is targeting a specific impulse of 1,250 seconds, which the company claims will put
27:56its hybrid rocket ramjet engine in line with standard ramjet performance.
28:01But that's still 80% less efficient than the 747.
28:05And rather than 400 passengers, it carries only 12.
28:10Airplane efficiency may not be the sexiest topic, but all of these planes will undoubtedly
28:15be worse for the environment than subsonic travel we have now.
28:18It's not just the environmental impacts either.
28:20This fuel costs a lot of money, and it might just be the make or break reason that flying
28:25supersonic just isn't profitable for these companies.
28:29It's a lovely goal.
28:31Everyone wants to go higher, faster, farther.
28:33We don't like to use that phrase too much, but at some point there are limits.
28:39In the case of airplanes, the limit for speed is Mach 1, a little bit below it, practically
28:44speaking, to be commercially viable.
28:46Beyond that, no.
28:48Here's a graph of jet fuel prices over the last 50 years.
28:52This flat period of low prices was Concorde's era.
28:55Since then, fuel prices have shot up.
28:57So while a trip on the Concorde in 1999 costs about $154 per passenger and fuel, that flight
29:04today would cost over $700.
29:07And for Boom, the numbers are looking much worse.
29:10They've made a commitment to sustainable jet fuel.
29:12Today's airplanes are actually only 50-50 compatible with sustainable aviation fuel,
29:17and Overture were designing to run on up to 100% sustainable fuel.
29:22Sustainable jet fuel is a type of jet fuel made from either renewable sources like plants
29:25or algae, or repurposed waste that's intended to have a lower carbon footprint.
29:30The thing to know is that SAFs remain very expensive and very rare.
29:35So typically, SAF costs between two and five times as much as fossil jet fuel.
29:40And it only accounts for two-tenths of 1% of fuel use today.
29:46So it's very much a nation technology.
29:48So if Boom achieves their 25% more efficient than Concorde claims, and SAF costs the $8
29:54per gallon that it cost recently, that means the fuel alone for each passenger on a flight
29:59from London to New York would be around $1,500.
30:03If SAF hits the highs of $10 that it did multiple times last year, that would be almost
30:09$2,000 in fuel costs for every single passenger.
30:14Those are really rough estimates, and maybe Boom will manage to squeeze a little more
30:18efficiency out of their planes.
30:20But it gives you an idea of just how expensive these fuel costs could be.
30:24We reached out to Boom about this, and they told us they're aiming for a $5,000 round
30:29trip ticket.
30:30If that's true, $3,000 to $4,000 of that would be fuel alone.
30:35They told us,
30:36We've designed Overture to be profitable for airlines at fares similar to first and
30:41business class.
30:42That includes fuel costs, which we expect to go down over time as the supply of SAF
30:47increases along with demand.
30:50And there's one other big problem with this plan.
30:52SAF often isn't actually as sustainable as it sounds.
30:56Well, there's a lot of diversity hiding under that term, sustainable aviation fuels.
31:01A SAF can be produced in a sustainable way with a good feedstock and reduce emissions
31:06by 80% or more compared to fossil jet fuel.
31:11But it also can be produced in a way that actually makes it more polluting than fossil
31:15jet fuel.
31:16So to take an example, if you take palm oil that's derived from like a deforested area
31:22and turn that into a SAF, then that's actually going to have higher life cycle emissions
31:27than fossil jet fuel, just because of all the carbon you released when you cut down
31:30the forest.
31:31The U.S. government is aiming for 3 billion gallons of SAF supply in 2030, which is a
31:36hundredfold or more increase from today.
31:39So those would be SAFs produced from corn or soy that offer modest, if any, greenhouse
31:44gas benefits.
31:45It's going to be a tough task to balance out fuel costs, environmental damage, and
31:50heat problems, all while making a comfortable and affordable ride for passengers.
31:56Now that we've seen all the supersonic prototypes, who's actually going to fly on these things?
32:01All the CEOs we talked to said similar things.
32:04I think it's typically the business traveler, folks that you would see flying in business
32:10class or first class today.
32:11When we talk to people who are the most frequent international travelers in business class
32:18and first class, 97% of them say they want supersonic flights.
32:23You land in Japan at 2 p.m. your time, but it's more like 7 a.m. their time, and you
32:28take an Uber or you ride a taxi to the factory.
32:31You're able to have a meeting with whoever you're meeting with for like three hours.
32:35You can then board a flight and get back home in time for dinner.
32:39And in a world of super fast internet and remote calls, do we really need to be flying
32:43these CEOs across the planet at hypersonic speeds?
32:47And finally, for the nearly 10% of CEOs who are super commuters traveling 100 miles or
32:53more to work, one study found that they consistently underperform their localized counterparts,
32:59causing their firms to lose value and their tenure to be shorter.
33:03It's even worse if they own a boat or live near a golf course.
33:06It turns out the only person who would actually fly supersonic and be home in time for dinner
33:11was the pilot of the Concorde.
33:13I would drive my wife early in the morning to the station, our local station.
33:20She'd get on the train, commute into the city, and I would go to Kennedy, get in my Concorde,
33:26fly to London, go swiftly through customs and immigration and come out the other side
33:32and get on as a passenger on the evening Concorde out of Heathrow.
33:38And I'd get back into Kennedy, get in my car, drive up to Katona, and pick my wife
33:45up at the station, she having been to work all day, and me too I suppose.
33:50But even for the ultra wealthy, are they going to pick speed over comfort?
33:54When you can already fly in luxury on a private jet, is the few hours saved going to be enough
33:59to entice people back to supersonic?
34:02Could there be a faster supersonic future?
34:04Maybe.
34:05But it's not happening any time soon, and there's a lot of reasons that people should
34:09think about and be concerned about what the implications of that future might be.