Founder Interview: Hermeus' Hypersonic Airliners

DALLAS — American startup Hermeus is working on the development of commercial hypersonic airliners, which will allow passenger planes to travel six times faster than they do now.

According to their State of the Company event held recently, the Atlanta-based company started the year strong with a US$100m series B funding round. It has grown its team to 100 employees and massively built out its facilities to support its leading-edge manufacturing capabilities.

“This confluence of people and hardware has led us to some major technical milestones. We demonstrated turbojet to ramjet mode transition with our engine, Chimera, and finalized the design for our first vehicle, Quarterhorse,” the company stated in a recent post on LinkedIn.”

Hermeus states that they are developing each of these platforms with sights set on making the commercial hypersonic flight a reality with Halcyon, a passenger aircraft capable of traveling 125 transatlantic routes at Mach 5 speeds. 

Airways was able to have a chat with one of Hermeus' founders and its Chief Operating Officer, Skyler Shuford, about their long-term plan and how it's unfolding.

WI: What does Hermeus do? 

SS: The big picture, long-term vision of the company is to radically accelerate air travel. Not just a small incremental change, but something that fundamentally alters how goods and people move around the world. The key to getting to that big picture over the long term is how you approach the problem.

So it’s with technologies in the hypersonic space but by keeping it as simple and as focused and as in the realm of engineering versus science, as possible so that we can move very fast, not to invent anything new but bring existing technologies that are out in the world, together in a novel way that solves problems for customers along the way.

Near term, lots of products are focused on flight tests, then some national security products, and then in the long term, being able to carry commercial customers around the world. 

You’ve talked of hypersonic. What’s the difference between supersonic and hypersonic?

Different people have different definitions, but the one that we subscribe to here is just Mach 5. The physics starts to change but really it’s the lowest end of hypersonic but so five times the speed of sound. Then everything supersonic is from about Mach 1 to Mach 5.

How do you differentiate between the concepts of engineering and science as they pertain to aviation?

There are certainly some exciting new technologies in aviation that are still in a very early research phase, and we don't want to spend our time working on those problems because we have to start building a business.

I don't think it's a credible way to build a business. So we are focusing on component technologies that have existed for a long time.

And then for us, the way we think about engineering is figuring out how to bring those component technologies together rather than make a research breakthrough to be able to do what we're setting out to do. 

The idea of having an aircraft that runs five times faster is amazing because it will ease travel and work around the world. How did the idea of building faster aircraft come up? 

Myself and the other co-founders—there are four of us. We were working together at a company that developed high-speed flying. We were building a rocket plane as part of an Air Force program for the US Air Force called the X60A.

It was an experimental hypersonic flight research rocket plane, and so we were in this space before. Then, we saw this opportunity in terms of timing, with lots of private investment being interested in aerospace products, the U.S. government looking into partnering with private companies in a way that hadn't been the case maybe a decade before, and then all of the fundamental and component technologies being relatively mature to go pursue this.

And so with these three things, we figured it was the right time and that's when we decided to quit our jobs and focus on this full-time and try to make a significant improvement in how fast people can move around the world.

Do you have investors, and if so, with whom are you working to make this happen? 

Yes. We have a series of investors. I will just talk about the lead investors in each round. The first investment firm that took a bet on us was Khosla Ventures. They are a world-class investment team. They have invested in aerospace startups before.

One of the notable ones is Rocket Lab. And so they understand how aerospace development goes and looks, as well as the good and bad things associated with it, so they've been a great partner along the way.

So, they let our seed round into our Series A, which was led by Canaan Partners. They also have aerospace investments, so they understand what is laid in front of us.

Then our Series B was led by Sam Altman, who notably, very recently actually, put out through his company OpenAI, the ChatGPT and DALL•E AI programs but he is also an investor who is looking at all kinds of forward-looking technologies. So at each step of the way, finding world-class investment partners has been crucial to our success and they've definitely helped us along.

To build an aircraft like that, you are going to have to work with other aircraft-building companies.

Yes. We have one of our strategic investment partners in Raytheon, which joined in the Series B funding. They are an aerospace and defense contractor that’s been around for a long time and has built a lot of interesting and useful aerospace and defense products. So we've partnered with them; we haven't put anything out publicly about any kind of partnerships there, but they'll definitely be a part of the Hermeus story going forward.

But to counter that, most of what we do, we do in-house.

One of our core tenants of the company is vertical integration and so for things that are important to our business, we are going to bring those in-house and do them ourselves.

We have invested a lot in our manufacturing capabilities, being able to manufacture high-temperature materials like titanium, but then also even on the software and electronic side being able to write our own software to control this airplane, rather than have so many partners where communication and making engineering decisions become a lot more difficult because they're not focused on the same sort of problems.

As soon as you add another company to your partnership, then their incentives and risks also become yours. So we are very careful about what partners we bring on and we tend to bias toward doing things ourselves.

Can you tell us more about the engine you're building?

It's what's called a turbine-base combined cycle. The simplest way to talk about it is that it's a jet engine at low speed and a ramjet at high speed, and then we have some secret source to bridge the gap between the modes of operation, something that we recently tested.

We put out a press release and in a series of videos, about two weeks ago, showing the wind tunnel and the transition between those two modes of operation. So as far as we can tell, we are the first privately funded commercial company to have ever done this in history.

In light of the whole "net-zero" push from the aviation industry, where do you see yourself?

We have a company, and we are focused on building airplanes first, but we are also ready to use sustainable aviation fuels when they come online, so we are not spending much time focused on building those ourselves. That's a whole business in itself, and there are a lot of people and a lot of capable companies working on building sustainable aviation fuels.

There are also interesting things about our engine that make it more likely and easier for our engine architecture.

One kind of notable problem with sustainable aviation fuels is some of the materials in a jet engine can be degraded more quickly. So with our ramjet engine, there are not as many moving parts. It's a pretty simple engine so it might even work better under sustainable aviation fuels than a regular jet engine.

So it will also help with zero emissions?

It's not a huge focus for us at the moment. We are using regular jet fuel because sustainable fuels aren't quite there yet. That's where we are focused right now, but we are ready to move over to sustainable fuels when they are available. 

How do you see yourselves against the likes of Boom Aerospace?

Certainly, it's a different value proposition. They are in the supersonic space, and we are targeting hypersonic. So the biggest differentiator is the architecture that we have, so obviously, we are going faster. And there's space for speed to be a new metric that people pay different prices for.

Right now, people will pay more for a seat that lays flatter, for more legroom, and for expensive drinks. But what we want to see in the future is people spending more resources on things that provide more value, not just more luxury.

I don't think anyone likes being on an airplane. I think everyone would prefer to be on the ground with their family or in a different country seeing the sights of doing business.

So, there's a place for both. I don't see any real competition with Boom Aerospace. And also, what was really focused on in the near term is working with the U.S Government to provide capability and value to them. And I am unsure if there are any kind of direct efforts beyond some small contracts that Boom is working on there.

What do you think the cost of flying will be with a commercial hypersonic aircraft? 

Development costs for a vehicle like this are going to be high. Any passenger-carrying aircraft is going to be an expensive development program. But something we set out to do was put ourselves in a business-class pricing range.

There's still a lot to learn about how to maintain aircraft like these and how to make them as reliable as current aviation, which is why our first series of products will fly no people; there won't be anyone on board for the first few products we are building so that we can learn what we need to become a world-class aerospace company. Then, we can start approaching those problems of making sure it's just as safe and reliable as current aviation.

But the target for us is business. Making it profitable for business-class prices and then having airlines decide what price make sense given the market and the routes. But like I said, there's lots of uncertainty and lots to learn before that.

I read from your website about an aircraft you're building called Halcyon. How big will it be?

It has a capacity for about 20 passengers, so it is sized for the expected passenger flow in the coming decades. It is also sized for overwater routes, and it has all the systems that make up that vehicle.

It will be bigger than some of the larger business-class private jets but obviously smaller than some of the wide-body aircraft that cross oceans. 

Given the track record of current supersonic and hypersonic forays, where do you see yourself in a decade? 

Some folks think that Concorde was a failure, and I think there's a little bit of nuance there to call out. Was that it? It flew for 30 years.

Once the airliners figured out the market for that vehicle, they were able to price it accordingly and it flew for a long time. It basically retired from old age. But where it had troubles was on the development side.

What happened during the development program was that the regulations changed about flying supersonically over land. If the multinational developers had known that the regulations were going to change, and all of the overland routes were going to go away, I bet that they would have made a much smaller vehicle to service those markets. It lost money in the development but operationally, I would consider the success of a plane that flew for 30 years.

I think it comes down to the economics of the business and that is something that we focused on from the beginning. That is how to align the technical plan with the business plan so that we build the right scale of the company along the way, which is why we are not going immediately for the commercial market.

We are focused on some more near-term smaller vehicles that solve problems for customers and do so without putting a person on board while we learn to grow and establish a financial foundation.

Okay. So in a decade, you see yourself making something like Concorde?

It will be faster than that. But yeah, something that flies commercial passengers is our North Star. It is our sort of guiding focus.

That helps us inform what technologies we pursue and what contracts we go after because we want to move as quickly as possible toward that long-term goal in a way that is also financially valid, safe, and reliable.

Thank you for taking the time to talk to us.

It's exciting. We have a long way to go, but we are making good progress, especially in the near term with our first vehicle, Quarterhorse. We have a lot of fun, a small but high-performing team, and every day is a new but exciting challenge. 

Featured image: Hermeus