October 12, 2018

#S02E06 - Will Supersonic Travel Ever Make A Comeback?

Since the Concorde was retired in 2003 - the world hasn't seen another supersonic transport aircraft. But there are a new wave of companies trying to bring the idea of a supersonic passenger aircraft back from the dead.

#S02E06 - Will Supersonic Travel Ever Make A Comeback?

The Concorde was one of the most beautiful aircraft ever created and it really set the bar for supersonic transport. However since the Concorde was retired in 2003 - the world hasn't seen another supersonic transport aircraft. So this week on Moonshot we’re going supersonic… diving into the new wave of companies who are trying to bring the idea of a supersonic passenger aircraft back from the dead.


This episode of Moonshot was hosted by Kristofor Lawson (@kristoforlawson) and and Andrew Moon (@moonytweets).

Research for this episode by Mahalia Carter.

Our theme music is by Breakmaster Cylinder.

And our cover artwork is by Andrew Millist.



KRIS: July 25… 2000. An Air France flight taxis down the runway at Charle de Gaulle airport in Paris… it was just a normal day at the airport until suddenly it all went wrong… [explosion sound]

[Man: “Good Evening, 113 people were killed today in the first ever crash by a Concorde”]

KRIS: This is the day that it all went wrong for Concorde - the world’s most iconic commercial supersonic jet… and just three years after that incident the concorde took its final flight.

[Man: “Taking off into a New York sunrise, BA 002, the last supersonic passenger flight to cross the atlantic”]

[Woman: BA flight 002 from New York touched down at just after four this afternoon, it was the last of three Concordes to land at Heathrow today ending one of the most glittering achievements in aviation history, supersonic passenger travel.]

KRIS: Welcome to Moonshot - I’m Kristofor Lawson.

KRIS: And since that final Concorde flight the world has not experienced the joy of supersonic passenger travel. But this week on Moonshot we’re going supersonic… diving into the new wave of companies that are trying to bring the idea of a supersonic passenger aircraft back from the dead.

KRIS: But before with cross that sound barrier… here’s a word from our sponsors.



Bob Van de Linden: “Well it had always been the dream of aircraft designers and for that matter, people who flew [on aeroplanes as well] to go as fast as humanly possible, and for the longest time they thought there was such thing as a barrier, a sonic barrier. There really wasn't, that's all a matter of physics.”

KRIS: This is Bob Van de Linden - the curator of air transportation at the Smithsonian National Air and Space museum in Washington, DC. Bob had the opportunity to fly on the very last concorde flight from Paris which was making its way across to the museum.

Bob Van de Linden: The press was out there, there was a lot of commemoration, and I guess celebration, because they were celebrating the 27 years it was in service, a little bittersweet. But, you know, they had the firetrucks out with jets of water over it. We had a French Air Force mirage escort us to the coast. All the press was there. It was very nice. It was great, but it was the last flight.

KRIS: The Bell X1 was the first manned aircraft to travel supersonic in 1947… and it didn’t take long before several countries started a push to develop commercial supersonic transport - or SSTs. This push all came to a head in the 1960s along with the big rush of development in the aeronautics and space industries. This was the age of the moon missions - and at the same time as we were trying to put man on the moon people were imaging what a commercial supersonic plane would look like. And although the Russians were the first to fly a supersonic transport aircraft in 1968, it was the Concorde - a joint project between Britain and France - that really captivated the world’s attention.

[News Report: “For Concorde 001 this was the chance to prove she was the superbird everyone had hoped and worked for.”]

KRIS: Concorde first took to the skies in 1969 before entering commercial operation in 1976 flown by both British Airways and Air France.

[Man: “They were champaign days for Concorde, there was a queue to fly in the most exciting aircraft the world had ever seen”]

KRIS: The Airline could travel at almost Mach 2…. Meaning it was flying twice as quick as the speed of sound… resulting in trips that were more than twice as fast as your average commercial jet which travels at subsonic speeds.

KRIS: And it was the ability to move at such high speeds that attracted a particular sort of wealthy individual.

Bob Van de Linden: And I mean very wealthy. Or business people. But again, we're talking CEOs, we're not talking mid-level managers here because it was expensive. In 2003 when it was retired it cost $6000 US to fly one way. That's a lot of money today. Significantly more expensive than first class and yes it took half the time, but a lot of the very wealthy, even then, didn't think it was worth the money. Just hop on a big, comfortable 777 or 747 or a nice Airbus, if you're wealthy, sit up front and first class, lean back and go to sleep and wake up in London, wake up in Paris.

KRIS: When you would go on board a Concorde, like, what was special about the experience apart from the fact that you were flying really fast?

Bob Van de Linden: I have to be honest with you. That's it. The aeroplane itself was very small. It only sat 100 people. You've got four across sitting. The seats are about 17 and a half inches wide. The width of the seat is the same as in coach. You do have leg room, but you're in a small tube. It's almost like being in a commuter jet, it's much smaller. There's no inflight entertainment, well there was, you just watched the mach metre up on the wall, which was a lot of fun believe you me, watching that go up. Tiny windows, but you could see out very well, but they're right next to your head. But superb service ... I mean, just, it's the best. When people complained about airlines it was like well, yeah, it's generally pretty bad, but not on the Concorde. Believe you me, it was magnificent.

Bob Van de Linden: I was on Air France and the flight was about three and a half hours, and a proper French meal takes two and a half to three. By the time we got the cruising altitude, we were served our dinner. Actually would have been lunch, but it was soup to nuts, and by the time we finished, you look out the window and we were about ready to land. It was very nice. I loved it. Believe you me. It was great.

KRIS: Concorde was a marvel of engineering with it’s beautiful delta winged design and a nose that could be lowered to allow the pilots to see the landing…. but it faced a number of issues. Firstly the cost of operating the aircraft, flying at supersonic speeds used an awful lot of fuel and the resulting ticket prices meant that not everyone could afford to fly, and those that could afford it expected that they would be getting on to a Concorde flight, which meant that there was always one plane sitting on the tarmac as a backup, waiting, in case something went wrong. Secondly it was restricted by the routes it could fly due to the noise generated by the aircraft, and also the high fuel usage meant that it wasn’t good for transpacific flights. And thirdly it had a huge environmental impact. So while the Air France crash may have been the beginning of the end for Concorde and has left a lasting memory in people's minds, it certainly wasn’t the main issue facing the aircraft when it was put into retirement.

Bob Van de Linden: Air France in particular knew that it was probably the right time for it because Airbus, which was the successor company to the manufacturers of the Concorde, had earlier announced that they could no longer support the aeroplane. At that point there were only 12 in service and spare parts were getting scarce, and making new ones was outrageously expensive, and there really wasn't a market for it. So Airbus pulled the plug on it, and Air France and British Airways, the only two airlines that ever operated it, had to retire them.

Peter Coen: You know, concord really was a pretty fantastic technological achievement, you know, especially for the time, it's amazing really.

KRIS: This is Peter Coen…. Peter is project manager for NASA’s commercial supersonic technology project - which is specifically looking at ways that you can redesign a supersonic aircraft to reduce the impact of the sonic boom.

Peter Coen: You know if you look at some of the issues that Concorde faced, those really are still the barriers to supersonic flight and we tend to put them in two categories. One is environmental, and those are the things like the noise from sonic booms, noise around the airport when Concorde was taking off and landing, and high altitude emissions.

Peter Coen: And the other group of barriers is really efficiency and that really comes down to fuel consumption and essentially passenger miles per gallon, how efficient the aeroplane can move a large number of people. That also gets into, how efficient the aerodynamics are, how efficient the engines are, et cetera. And then finally, how does it operate in the airspace system so that it can make best use of its speed. Essentially you look at Concorde, we want to make it cleaner and greener and more efficient.

KRIS: Now this idea that NASA is working on to reduce the impact of a sonic boom is a really big one because in the United States, Europe, and many other places around the world - flying over land at supersonic speed is banned because of the feared impact of the sonic booms. And it’s this restriction which had a heavy impact on the economics of the Concorde.

Bob Van de Linden: Because of sonic boom, most stations would not allow the aeroplane, any SST, to fly overland. Well, once you do that, you just eliminated half the routes around the world. And therefore you just eliminated a huge market for the aeroplane. No domestic US airline is going to buy one, if you can't fly supersonically what's the big deal?

KRIS: But NASA is keen to see supersonic transport back in the skies and plans to overturn this by designing planes that can actually reduce the impact of the sonic boom.

Peter Coen: People have been studying sonic boom essentially since the first one was heard trying to figure out what it is and then pretty much as soon as they understood that, how to reduce it. So the math and some of the concepts for a shaping an aeroplane so that it produces something other than the typical BOOM BOOM of a sonic, that's heard when a supersonic aircraft flies overhead, really goes back to the 1960s and early 70s. But, more recently within the past 10 years or so, we really think we've made a breakthrough in terms of how you would shape the aeroplane, to distribute the shock system so that the shocks don't coalesce and pile up on top of one another resulting in a sonic boom.

KRIS: Sonic booms, as Peter mentioned, are caused by a buildup of sound waves when flying faster than the speed of sound. They aren’t caused by breaking the sound barrier - because as you’ve already heard,  there isn’t really such thing… however they aren’t actually heard until you’re flying at around mach one point one.

KRIS: And yes we also said sonic booms - because sonic booms are heard constantly throughout a flight  - so it’s more a series of booms that are heard on the ground rather than one individual boom.

Peter Coen: If you think about it, takeoff and landing noise affects people around the airport, but a sonic boom, essentially as soon as the aeroplane exceeds the speed of sound and begins to cruise at supersonic speeds. It's constantly making a sonic boom. So everybody under its flight path is exposed to that sound. So it's really important to us to get it down to the point where in some conditions you may not even hear it on the ground.

Peter Coen: If I'm standing outside my office, and I'll hear a sonic boom when the aeroplane flies over, if you're 20 miles away, when the aeroplane flies over you, you'll hear exactly the same sound.

KRIS: And NASA is actually building a plane in partnership with Lockheed Martin which will be designed to specifically reduce the sound of a sonic boom - from a BOOM… to more of a thud.

Peter Coen: If you're in a thunderstorm and the storm is right overhead and you get the lightning flash and the thunder right at the same time, that's a sonic boom. A little while later, the sun's come out, the storm is off in a distance and you hear that faint rumble of sound, that's a sonic thump. That's what we're going for.

KRIS: The contract to build NASA’s prototype plane is worth almost $248 million US dollars… and the plan is to have this plane in the air in 2021. Assuming all goes well, If NASA can prove that it is actually possible to reduce the impact of the sonic boom to an acceptable level, they’re hoping to reverse the current legislation and open up a market for domestic supersonic transport.

Peter Coen: NASA is working with the FAA and the International Civil Aviation Organisation, to develop the framework for a certification standard for supersonic overland flight. So in other words, if you came forward with a design that you said was quiet enough to fly over land, how would you prove that to the certification authorities. So we're putting that framework in pieces.  Now that's standard as they call it, we'll generally have a metric, a number that you have to show them, and a procedure for calculating that number or recording that number and a limit. This is where our research comes in. We want to provide the FAA and the ICAO with a database of response to sonic boom sounds from people on the ground that allows them to say, "At this level or below, the aeroplane is quiet enough that it will be allowed to fly over overland at supersonic speeds." So really our goal, and a success to NASA means the ICAO and the FAA and the other international rule-making organisations have the data they need to change the rules about supersonic overland flight.

KRIS: And if NASA can successfully overturn this issues with domestic supersonic travel - it should certainly open up more opportunities for commercial SSTs.

KRIS: But that hurdle around domestic flight isn’t stopping a new wave of companies from taking on the challenge of supersonic supersonic transport.

KRIS: And we’ll have a look at one of those companies - right after this break.


KRIS: Welcome back to Moonshot - I’m Kristofor Lawson…. And as I mentioned before the break, there’s a new wave of companies that are taking on this challenge of building a supersonic passenger jet. And one of the leaders in this race is a Denver based company called Boom:

Blake Scholl: I went to Amazon shortly after school in 2001 when my parents thought it was still a bookstore and kind of had this career working in areas where everything was getting faster and better, our computers, our communications, even how quickly we can get things delivered to us when we shop online but weirdly with aeroplanes it's a very unique story in the history of technology that we had a capability in Concorde and instead of taking it more mainstream the way we've done with everything from electric cars to cellphones, we actually stopped and went backwards.

KRIS: This is Blake Scholl - he’s the CEO and founder of Boom Technology - a Denver based company planning to bring back supersonic transport in a really big way.

KRIS: Blake is a computer scientist by training - he’s worked in a number of successful startups including Amazon, and founded a company which later sold to Groupon, and around four years ago he sat down and started sketching out ideas for what his next company might be.

Blake Scholl: What I realised in thinking about what I wanted to do next was that all start ups were hard, there's no such thing as an easy one, you're going to go through hell so what you need to do as a founder is pick a mission that inspires you enough that you're never going to get up in the morning and say why am I doing this, it isn't worth it, you're always going to keep going, you're never going to give up.

KRIS: And because Blake is fascinated by aircraft - at the top of Blakes list of ideas to work on was something with wings.

Blake Scholl: If you look at Concorde, it was a massive technical success but an economic failure, tickets cost $20,000 round trip New York to London in today's dollars and you just can't fill 100 seats like that. And the fundamental reason that the cost spiralled out of control was that the fuel economy is poor.

Blake Scholl: If you start saying well, okay, everyone says it's a massive leap from Concorde to make supersonic travel available at economy prices but there's this thing called business class which is 10% of seats but half the revenue. What would you have to do versus Concorde to match business class kind of fuel economy, business class pricing, and it turns out the answer you can get from a three aligned spreadsheet you can [build out of] Wikipedia and it's 30%. So if you can beat Concorde's half century old technology, remember this thing with slide rolls and wind tunnels on drafting paper, if you can beat that by 30% then all of a sudden you could have a second generation supersonic transport that gets you there in half the time but at the same fares you'd pay in business. And so once I realised that, uh-huh, well that doesn’t sound impossible.

KRIS: Now let’s not forget that Blake is a computer scientist - he wasn’t an aircraft designer. So back in 2014 he started reading as much information on aircraft design as he could - he bought textbooks and he even took a class. And after a while he knew enough that he put many of his ideas on paper and then took them to a professor at Stanford to check if all his assumptions were correct.

Blake Scholl: And he looked at it, he clicked around and said, "You know Blake, if you're going to do this you should really try harder because all these assumptions are conservative." And so at that point it was very much well, either you have courage or you don't and if you do you're going to go for it. Now, it turns out he was wrong, the assumptions were aggressive and it's incredibly hard to get to them but neither of us knew that back then so the company got started.

KRIS: That courage to dive right in - led Blake down a path to building a team.

Blake Scholl: You know a lot of people told me I was crazy, that this could only be done by governments or militaries, that you certainly couldn't do it as a new company, that it would take too long and cost too much money or it would be too hard. There's a whole bunch of standard false assumptions about what startups can do as well as what's possible with aeroplanes but you also, you judge them for do they make sense on their own terms. A bunch of people told me you can't do that, it requires variable geometry in the engine intakes and that's really hard, you stop and say, "Wait a minute, the Concorde did that and I may not be an aerospace engineer but I'm pretty sure if it's been done before it's not impossible."

Blake Scholl: And so you'd find the people who could stop, put aside the traditional wisdom and say well let's just look at this from first principles and say what would it take... and then you find a way through.

KRIS: Designing aircraft is hard, it takes a lot of time and money to get right because there’s an awful amount of complexity in the build, and you need to make sure it’s safe. Which is why there’s really only two main manufacturers of commercial passenger aircraft, Boeing and Airbus. So how does a startup like Boom actually get off the ground and get to the point of delivering a production ready aircraft?

Blake Scholl: What we decided to do is rather than going straight into production on a 55C, 200,000 pound, mach 2.2 supersonic transport which will be frankly one of the most sophisticated safety critical machines ever built, you say well let me go build a subscale prototype, something a little bit smaller but the speed and let me go prove this is possible in a reasonable amount of time with an obtainable amount of money. That's what XB-1 is, it's a one third scale version of our first passenger aircraft that will go fully mach 2.2, we'll do it with a pilot and one passenger and we'll prove that you can do this a as a startup. It's akin to, you know, the Spaceship One for private space.

KRIS: Now the XB-1 is really a proof of concept, but if Boom can prove that their technology actually works on a small scale, and show that it is significantly more efficient than the Concorde, it will be much easier to lock in all the financing needed to put the aircraft into production. Boom has raised almost $50 million US dollars including a $10 million investment from Japan Airlines, and Virgin have also registered interest in purchasing the aircraft. The price is set to be around $200 million US dollars but they already have around 80 pre-orders for a plane that hasn’t even left the ground. But the team is making good progress and are on track to have the XB-1 prototype in the air next year.

Blake Scholl: The horizontal tail is in the hanger, the nose is getting built. I just looked at our inventory room over the weekend and the wheels and the tyres are here so this is well on its way to becoming an aeroplane. We've hired the test pilot whose going to fly it and that bird's going to be in the air towards the end of next year.

KRIS: And once they’ve proved the prototype that begins a six year design, development, and approval process before the aircraft can be put into production. But all going well Blake is hoping to have Boom’s first SST in service by around 2025.

Blake Scholl: Aeroplane people say wow, how can you do it so fast and non-aeroplane people say why in the world does it take so long and to answer kind of both of those, the reason it's only six years is that all the technology for this already exists, we're not counting on any kind of new materials or aerodynamics, this is stuff that's been proven out on other aircraft, the aerodynamics are a optimised version of what flew on Concorde, the materials were proven out on the 787 Dreamliner, the engine's an adaptation of the same stuff that powers every modern large airliner. And so you're doing an engineering and safety testing and regulatory approvals process, rather than a science project, and that's really huge for making this feasible. And I think that's the basic answer to why this is actually happening now finally. But it takes a long time because it is safety critical. There are many, many, many parts on the aeroplane and aeroplanes don't have optional parts, they're all needed. And we're putting 55 souls on it, it has to be rigorously tested so that day in and day out it is safe, the kind of aeroplane we would trust for our friends, our family and our loved ones.

KRIS: One of the issues with Concorde was much of the body was built with aluminium - which doesn’t handle well at the high temperatures generated when travelling at supersonic speed. In fact the aircraft would actually change size while it was in flight, which in many ways Concorde actually handled in a really fantastic way, but it is an issue that Blake says can be eliminated through the use of more modern materials.

Blake Scholl: Concorde would grow 15 inches in flight just from the heat. And let me tell you, it's a tricky thing to go off and design an aeroplane that's gonna get bigger on the outside, while staying the same size on the inside and it's supposed to be airtight. But carbon composites basically don't grow. It was very, very slightly and it can handle higher temperatures than aluminium, which is what enables us to go faster than Concorde did. So Concorde is mach 2.0, we're mach 2.2, so about 10% faster.

KRIS: As I mentioned earlier in the show - one of the issues with Concorde was that it was very limited in which routes it could fly due to the bans on supersonic overland flight, and also it didn’t have the fuel capacity to make trans-pacific flights. But Boom is not really concerned about the domestic flight problem because they’re focusing on highly-travelled international routes, where there’s no issue with travelling at supersonic speeds.

Blake Scholl: So, routes like San Francisco to Tokyo, Seattle to Shanghai, Boston to Paris, routes where you can fly 90%-plus over water, and the whole question of, is a sonic boomer problem, is just moot.

Blake Scholl: That said, personally, I think sonic boom problem is exaggerated. There's a great episode of Mythbusters, where they test the myth, "Can you break a window with a sonic boom?", and it turns out, the answer is yes, but you got to fly 50 feet over the ground, supersonic, and put the boom, like, smack dab in the middle of the window. And let me tell you, if you're 50 feet over the ground, supersonic, as an airliner, you got a bigger problem than a broken window.

KRIS: Have you personally flown on a supersonic plane?

Blake Scholl: No! I've been on Concorde, but only in museums.I kind of gave myself a life goal, in my mid-twenties, to go Mach 2, and I put a Google alert on Supersonic Jet, because I want to be first to know when I can go do that. And after enough years going by, I've seen no credible effort, I thought, "Well, jeesh, if I'm going to do this, I might have to start the company and build the jet to make it happen."

KRIS: You're now four years into this journey. What's the biggest thing that you've learnt, through starting boom?

Blake Scholl: I think it's that big, inspiring missions have a way of being easier than smaller ones that look like they're actually easier. So let me unpack that for you. My last company was a mobile e-commerce software company, the kind of thing that you think would be really easy to do. But man, it was hard to hire people. It was hard to convince them, "Why did you come work with us?", and how we're different from the million other apps in the app store.

Blake Scholl: And It was, and you get up in the morning, and wonder why you're spending your life on this. Versus, you can work on supersonic jets, and especially, if you can articulate to people, why it matters to the world, and why it's going to be a better place to live, when you can get around the planet more easily, you can get some amazing people to come work with you.

Blake Scholl: We have a guy from SpaceX, who previously owned the upper stage of the Falcon 9. We have a guy from Airbus, who owned the wing on the A380, which is the largest commercial wing ever built. We have a guy who owned propulsion on the SR-71 Blackbird at NASA.

Blake Scholl: I could keep going, and if I were working on a all composite business jet, or some less important idea, I would never have this team. And then, when you can collect a whole bunch of great people, all of a sudden, these grand challenges, that look like they'd be nearly impossible, start to become very possible.