The future of hypersonic air travel isn’t as far away as you might think — in fact, it might be in your backyard.

Hermeus is an Atlanta-based startup focused on bringing hypersonic air travel to the masses. Think the supersonic passenger airliner the Concorde, which flew from the 1970s to 2003 — but faster. Founders A.J. Piplica, Michael Smayda, Glenn Case and Skyler Shuford started the company in 2018 and are now working on designing a hypersonic aircraft that could take passengers from New York to London in 90 minutes. 

To build a hypersonic plane, they need somewhere to test the engine. Shortly after Hermeus started, they chose DeKalb-Peachtree Airport (PDK) to be their engine testing ground. The Reporter spoke to Case about hypersonic travel and why they chose PDK. 

Hermeus co-founder Glenn Case.

Can you explain the background of Hermeus and how you got started? 

We were founded back in November of 2018. We were working for an aerospace company here in Atlanta at the time, but also working in the hypersonics world. We saw this incredible opportunity for commercial hypersonics and sort of jumped ship — decided to jump off the cliff and try to build a plane on the way down.

What’s the goal that you’re working towards? 

Our end goal is to transform transportation by building Mach 5 aircraft. Mach 5 aircraft means around 3,300 miles per hour, or five times the speed of sound. 

It’s been pretty well studied that anytime humankind has increased their speed of travel — be it from walking to horses, or horses to automobiles, to ships to aircraft — that a large economic impact follows suit. It’s a lot of economic growth in terms of trillions of dollars of real, new growth in economies. That’s one of the ways we really care to change the world — by speeding up travel. Not only does it make your life a lot better, because of life lived on the ground and not the air, but it brings real, new growth and new economies to many parts of the world.

How fast will that Mach 5 plane be able to travel in terms of going from one place to another?

You’re looking at New York to London in 90 minutes. And that 90 minutes includes taxiing out, acceleration up, cruise and then deceleration and landing. 

That really creates an international, intercontinental flight that is more along the lines of a regional flight today. I don’t know about you, but I certainly don’t hesitate to hop on a flight when I’m flying from Atlanta to the Mid-Atlantic or somewhere around there, where it’s only about an hour-and-a-half [away]. I’ll take a weekend trip somewhere on a plane there, but once that aircraft flight hits six or seven hours, those trips have been fewer and far between. But think of what would happen if that flight to Paris was more akin to a regional flight. That’s essentially what we want to do. We want to shrink the world to a regional-type place.

What’s the timeline for having that plane ready to go? 

So that Mach 5 aircraft … that’s our vision aircraft for the future. We’re hoping that we might see that late this decade, as far as first flight testing of that aircraft. So it’s a long way to go. 

The more important thing for our company is figuring out how to bootstrap our way into that. We’ve got to make a company profitable before we can go and tackle an aircraft like that that’s gonna take billions of dollars to develop. No matter how deep pocketed the venture capitalists are out there, that’s a big ask when you’re going out and … asking for several billions of dollars before you see a cent of revenue. 

In the meantime, we’re busy developing several aircraft … that will allow us to create real revenues and build a company that can have the types of capital required to go do those audacious things. 

How long has Hermeus been working out of PDK?

Pretty shortly after we founded the company. We had started to talk with Mario [Evans], who is the airport rirector there, and the folks over there at PDK as early as 2019. As soon as we signed on the dotted line for our first fundraising round, we worked out a deal where we could basically set up shop there on [a decommissioned runway.] We’ve been utilizing a piece of that land there for some early testing that we’ve done with our demonstration engine. 

The airport staff has been great, very kind and helpful to our cause. We couldn’t ask for better support out there. We’ve been out there since, and we’re looking forward to great things in the future.

One of Hermeus’s prototype ‘hypersonic’ airplane engines.

What exactly have you been testing out there? 

Our demonstrator engine, which is essentially a demonstrator version of a turbine-based combined cycle. For the layperson, that means it operates as a gas-driven engine at low speeds — up to around Mach 1.5 or so — and then we have a pre-cooler on the inlet area that allows us to push that gas turbine engine up to around Mach 3.

At that point — at Mach 3 — we transition to what we call a ramjet. A ramjet is essentially a device that uses the forward velocity of the aircraft to compress the air. So now you don’t need an engine to compress that air, and you can just burn it directly and provide that thrust. So that turbine-based combined cycle marries those three operational modes together as one for that full-range propulsion capability.  

I understand that you’re moving forward with a possible new deal with PDK. What does that look like from your end? 

From our end, we’re working on a lease agreement for just under a 5,000-square-foot facility to continue our propulsion testing developments. This is a temporary facility — there’s no true power, water, or sewage out there. We’re having to handle all of that on our own on a temporary basis, but that facility will allow us to get into the next set of testing for our flight engine, which is a little bit bigger engine than what we did for our demonstrator engine. That engine will go into our first flight vehicle that we’re developing. 

What does the timeline look like for getting that set up? 

Right now, we’re building that facility off site with a company called BMarko Structures. They’re close to the Rabbit Hill area [near Savannah] here in Georgia, so a local business. They specialize in taking containers and turning them into really cool buildings, so [they’re] taking recycled shipping containers and turning them into a test facility for us. So it’s really exciting to do that, and it’s got a really great look to it as well — a very industrial look for our test facility. 

They’re busy building that off site. They should be done building that in a couple of weeks or so. We’re still waiting on word on an approval of the lease from the … [DeKalb County] Board of Commissioners.

Why is PDK the best spot for this testing facility? 

PDK is, of all the airports in the Atlanta area, definitely the best one to work with in terms of being able to attract talent. 

It allows us to make noise — and that noise is well within the envelope that the airport currently operates under. No one’s heard us testing yet! It allows us to run up jet engines, which most places aren’t permitted for. PDK is obviously permitted for running up those types of engines. 

But it’s also inside the Perimeter, in a place that’s very accessible for folks that live either in the Brookhaven area, or Downtown and Midtown, or where I live in the north Alpharetta area — it’s still very accessible. So we’re able to attract a full range of people — folks that are young and might want to live closer to the city, or folks with families that might want to live in a little north of the city with more yard. It’s a great place that allows us to attract really great people, but also allows us to get our job done in terms of the permitting and everything associated with that.

Sammie Purcell

Sammie Purcell is a staff writer for Reporter Newspapers.