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Supersonic Flight: Are You Ready to Be a Bullwhip?

Post by
Jolie Hales

Chuck Yeager.  Concorde.  A bullwhip.

What do they have in common?


All three are breakers of the sound barrier.


Most of us already know about Chuck Yeager -- the first man to officially break the sound barrier -- and many of us have heard of the passenger airplane Concorde earning supersonic laurels.  But a bullwhip?


True story.  That sharp crack you hear when the tail of a bullwhip snaps in the air is, in fact, literally a sonic boom -- the moment an object has approached the speed of sound, which happens around 767mph (1234 km/h).


Allow one of our favorite Hollywood movie characters to demonstrate:


So while we often say that Chuck Yeager was the first person to break the sound barrier, people have actually been hearing that break since bullwhips were invented, which Wikipedia tells me was potentially around the 2nd or 3rd century (which must be true, if Wikipedia has been putting my generous $2.75 annual donation to good use).  


Share that fun fact at a party and watch future invitations come rolling in.


But centuries after the first crack of a bullwhip, high performance computing is well on its way to making commercial flight at bullwhip speeds the new normal.


The Sonic Boom


A little about that thunderous sound...


When an aircraft flies through the air, it creates a series of pressure waves both in front and behind it that travel at the speed of sound.  But as the aircraft speed increases past that speed of around 767mph, those pressure waves basically can’t get out of each other’s way quickly enough, causing them to compress together and merge into a single shockwave.  The result?  A sonic boom.


And not only do we hear it, but we can see it.


Check out this amazing photo of a U.S. Navy F/A-18 Hornet breaking the sound barrier in the skies over the Pacific Ocean just off the coast of South Korea:


Credit: Ensign John Gay, U.S. Navy, (7 July 1999) public domain

The white cloud pictured above is formed by the decreased air pressure and temperature around the tail of the aircraft.


And a sonic boom doesn’t just occur at the moment an airplane crosses the sound barrier.  It happens continuously as long as the aircraft flies faster than the speed of sound.  It can simply sound like a single clap of thunder based on where a person is positioned on the ground below.  


Having grown up next to an Air Force base, I can vouch for this.  There were many amphitheater stage performances where we young thespians had to pause for sonic booms caused by jets circling overhead, sometimes for what felt like an eternity.


“Oooooohhh-klahoma-”


Pause -- here come the jets -- cover ears and wait for three minutes… almost gone... Ok, go!


“-where the wind comes sweepin’ down the plain!”


You get the idea.


And while breaking the sound barrier might be incredibly loud to amphitheaters on the ground, supersonic commercial air travel has long been craved by modern society because it literally cuts the time it takes to fly in half, potentially turning an international business trip into a single-day event.


Less time traveling for work means more time with the family.  Or the dogs.  Or the house plants.  Whatever tickles your fancy.


This is the mission on which Denver-based company, Boom Supersonic, has embarked.  


Blake Scholl, CEO, Boom Supersonic | Credit: Boom Supersonic


“At Boom, we believe that life happens in person and that real face time beats FaceTime. And so our vision is to make the world dramatically more accessible by removing the barriers to travel, which are principally time, money and hassle. If we can chip away at those, we can build a world where more people can go more places more often, which is going to be a better planet for all of us to live on.” - Blake Scholl, CEO, Boom Supersonic


Only 1800% Over Budget


We’ve done supersonic commercial flight before.  


Concorde | Credit: André Cros, CC BY-SA 4.0, via Wikimedia Commons

Concorde, a joint venture between the British and French governments in the 1960s, was the first commercial supersonic aircraft ever developed.  It took its first flight in 1969 and entered commercial service in 1976, 1800% over original estimated costs.


That’s 1800% with two zeros.


When Concorde was developed, computational simulation on a project like this was nothing close to practical, so every element in Concorde’s development had to be physically tested.  This meant a lot of testing physical materials in actual wind tunnels.  And when you’re working with a first of any kind, there are bound to be numerous necessary iterations, with even the smallest adjustment amounting to millions of dollars in expense and many months of development and testing.


But after years of development and around $1.3 billion in spending, Concorde could finally take around 100 passengers to the skies on each flight, officially breaking the sound barrier with a maximum speed of 1,354 miles per hour (2,179kmph).


British Airways Concorde G-BOAC, May 1986 | Credit: Eduard Marmet, CC BY-SA 3.0 GFDL 1.2, via Wikimedia Commons

Concorde’s eventual success brought with it a great deal of excitement and optimism for the future of commercial supersonic aviation.  Requests for around 100 additional Concorde aircraft poured in from 18 major airlines around the world including United Airlines, TWA, and Japan Airlines, but were eventually canceled as rising costs along with other factors diminished enthusiasm for the project.  Hesitancy reached its peak in 1973 after a supersonic Soviet competitor to Concorde crashed in front of a live audience at the Paris Air Show, killing all six crew and eight people on the ground.


In the end, only British Airways and Air France flew Concorde regularly until its last flight in 2003.  Today, a round-trip ticket for a flight from New York to London on Concorde would cost the equivalent of around $20,000.  


So, yes, we’ve done commercial supersonic flight before.  We just haven’t done it right.


Boom Supersonic Pursues the Boom


Almost two decades after Concorde’s landing gear touched the ground for the last time, Blake Scholl, CEO of Boom Supersonic, is determined to bring supersonic commercial flight back to the skies, and he’s using high performance computing to get there.


“We've changed virtually everything about how we design and build aircraft. From an aerodynamic perspective, we've gone from developing in wind tunnels where every iteration takes months and costs millions of dollars, to be able to do things in computer simulation where you can test more iterations and arrive at a more refined, more efficient design.” - Blake Scholl


These days, aerospace engineers rely on computational simulation for digital research and development, shaving countless dollars and time off of each iteration, and resulting in the latest and greatest flight technology.  


“We have new materials, we've gone from principally aluminum to carbon fiber composites, which means you can build a strong, lightweight structure that can better withstands the stresses and temperatures of high speed flight. Propulsion has completely changed.” - Blake Scholl


Companies like Blake’s Boom Supersonic are once again rebuilding faith and enthusiasm in supersonic commercial flight, as the public is becoming more and more convinced that today’s technology can lead to a safer and less expensive aircraft when compared to Concorde.


Overture exterior render | Credit: Boom Supersonic

Boom Supersonic’s goal is to put passengers in the sky on an aircraft called Overture -- A beautiful rendition of what commercial aviation could look like, with the ability to hold around 50-80 passengers with plenty of legroom and armrests to go around.


Overture interior render | Credit: Boom Supersonic

But before Overture can become a reality, Boom has developed a smaller version of the aircraft at one-third scale to test first, called the XB-1, or “Baby Boom.”  Which, by the way, had a pretty awesome rollout video:



“Now how do we know this is all going to work? Well it's about testing, digitally and in physical hardware. One of the first things we built was a flight simulator, and this takes not just wind tunnel data but a tremendous amount of output from simulation. We've done about 66 million core hours of computing, mainly through Rescale, since we started the design effort on XB-1.” - Blake Scholl


66 million core hours.  Take that, 1960s aviation.


XB-1 | Credit: Boom Supersonic


“And if you ask yourself what that would look like in wind tunnel testing, it would be financially and timewise just absolutely impractical. We've been able to test hundreds of iterations of aircraft designs, which you just could not do with wind tunnels. We've gone to the wind tunnel just three times for XB-1 to get calibration data, to confirm that we're calibrated in CFD, and then to get a final sign off of the exact design that we're shipping.” - Blake Scholl


Running simulations for their digital R&D by using high performance computing has given Boom Supersonic the technological edge needed to make commercial supersonic flight a realistic and practical option.  And by taking advantage of cloud HPC, they’ve been able to optimize their workflows and iterate with compute power and availability that is virtually unlimited.  


This is exactly why Boom Supersonic’s passenger plane will not be 1800% over budget or years over schedule.


It’s also why XB-1 is set to physically take to the skies for testing this very year, and I know I’ll be watching.

And where Concorde’s development was the painstaking result of two collaborating Western nations, Boom Supersonic is a start-up with a current team roster of 150 people -- not a behemoth multi-governmental effort of any kind.  Since being founded in 2014, Boom Supersonic has raised a total of $210 million, and has a valuation of over $1 billion, making them an official unicorn.


In fact, I once emceed an event where Blake Scholl was giving a talk, and before he went on stage, we got to chatting, and he mentioned the company was pretty much started in a residential garage.  


Before cloud HPC, that would never have been possible. 

“When you look back in history, it's easy to underappreciate how much aviation has done for the planet. Isn't it interesting that we haven't had a world war since the dawn of the jet age? When you reduce travel times, people go more places more often. There was a six fold increase, for example, in travel in the first 10 years of the jet age to places like Hawaii that were previously inaccessible. And we think that Overture will kick off a similar growth in air travel, a similar increasing of accessibility of Earth. We want to live in a world where our children have not just read about places like Cape Town and Tokyo and Mumbai in a textbook but have actually been there. Imagine what it's like when everyone has experienced the wonderful people, places and cultures our planet has to offer. And Overture is the first in this series of aircraft.” - Blake Scholl

Blake estimates that the full-sized Overture will start testing flights in 2026, with flights on Overture becoming available in 2030.  As far as orders go, Boom Supersonic has already seen interest pouring in, with somewhere around 100 Overture pre-orders, including 20 from Japan Airlines and 10 from Virgin Group.  Boom Supersonic has even been approached about potentially developing Overture as a new Air Force One for President of the United States.

“We're going to continue to build them larger, more efficient, quieter and more environmentally friendly, and I think in our lifetimes we will see a world where every flight over about a thousand miles is supersonic.” - Blake Scholl

Blake walked through Boom Supersonic’s plans and journey at the inaugural Big Compute conference in February 2020, and his full talk is available here:

Ernest and I also covered the story on the Big Compute Podcast, which you can listen to here:

One thing is certain.  Supersonic commercial flight is about to make a major comeback, and supercomputing has been key to making that happen. 

Boom.







Jolie Hales is an award-winning filmmaker and host of the Big Compute Podcast. She is a former Disney Ambassador and on-camera spokesperson for the Walt Disney Company, and can often be found performing as an actor, singer, or emcee on stage or in front of her toddler. She currently works as Head of Communications at Rescale.