Europe's Hypersonic Moment - with Philipp Kerth, Co-founder of Hypersonica
Building the next-gen hypersonic missile.
“Europe might be behind on a couple of core technologies, but let’s make hypersonics ours.”
Philipp Kerth, co-founder and CEO of Hypersonica, sat with me to talk about what it takes to launch a hypersonic missile company at the end of a PhD, when defense was still an afterthought in most of Europe.
We cover why maneuverability is the hardest problem in hypersonics, what the new generation of hypersonic systems actually changes on the battlefield, and why building an entirely European supply chain - no US components - is as much a strategic choice as a technical one.
Transcript (lightly edited for clarity and flow) is below.
00:00 — The Founding Story
Louise Boucher: Before we dive into Hypersonica, I want to come back to your decision to launch this company. I met you more than a year ago, in January, and visited your factory near Munich — which is very impressive. But just to give some context: you grew up in Germany, went to Oxford for your PhD in hypersonics, and when you came back to Munich you built a missile company in 2023. Could you walk me through that decision? What was the moment you knew you were going to do this?
Philipp Kerth: There isn’t a single moment, so I’ll have to walk you through a longer story. For founding Hypersonica, three things came together. The first was technical fascination. The second was a very deep understanding of the values we have in Europe. And the third was really wanting to do something — wanting to have an impact and bring new things into the world.
The values piece is the most important one for me as the intellectual backbone of the company. I’ve always felt a deep appreciation for being able to grow up in a Europe that’s free, democratic, that has friendship between nations, that is safe and wealthy. The biggest contribution I could see myself make — coming out of a PhD in hypersonics — was to contribute critical technologies that will enable us to uphold those values in the future.
The technical fascination started very early. There’s a great science museum in Munich and my dad used to take me there as a child. I saw all those space capsules and spacecraft and from that point on I was lost — in a very positive sense. Hypersonics, making things fly really fast in a controlled way, combines physics, fluid mechanics, electronics, and materials. It’s a great topic.
The third thing is wanting to contribute something substantial and practical. When I studied at TU Munich, a couple of startups that came out of the university started to really take off. That inspired me to look deeper into entrepreneurship and see how big a difference you can make. All three things combined, and Mark and I decided to kick off the company.
04:47 — Hypersonics as Deterrence
Louise Boucher: You launched at a point where defense was less of an obvious topic for the general population. Did you experience pushback from friends or family?
Philipp Kerth: We started the company at a point where it wasn’t as obvious that hypersonics and deterrence would become such a big topic. But the concept of values that stands behind it was always clear in every conversation — that is what’s behind the company and essential to our DNA. Hypersonics is a possibility of having a shortcut to some very accurate and sovereign deterrence for Europe. That is exactly what we wanted to bring.
Louise Boucher: You mentioned your co-founder Marc. You met at Oxford with similar academic backgrounds, working on one of the hardest engineering problems in the world. Do you ever disagree?
Philipp Kerth: Marc was one year ahead of me in the PhD program. When he finished, he went to Bain for a year as a consultant, and then we founded the company together. We have a really good culture of disagreeing with each other in a very constructive and meaningful way. Speaking for both of us — we nailed that part. The results speak for themselves.
07:16 — What Iran and Russia Taught Us
Louise Boucher: Before we go into the technology, I want to get into the threat context. When we look at Iran and Russia, how they’ve used ballistics and hypersonics — are there lessons to draw for the future of warfare?
Philipp Kerth: There are lessons. I’ll stay careful on judging the specific capabilities of other systems, but I can give an overview of what hypersonic actually means. In aerospace, hypersonics simply means flying faster than five times the speed of sound — roughly 6,000 kilometers per hour. The reason there is a separate field is because temperature effects start to dominate the fluid mechanics at those speeds.
The new generation of systems combines hypersonic speeds with precise maneuverability. That’s where the real differentiator is. The Russian and Iranian systems are more on the less maneuverable side, but they do achieve hypersonic speeds. What we’ve seen overarchingly is that being able to strike very deep into enemy territory is an absolute essential capability. Multiple nations across Europe have published their demand for these systems.
Looking specifically at Iranian systems, they’ve been able to challenge air defense architectures with relatively high cost efficiency. Without making claims about their capabilities as singular weapon systems, we can infer that it is essential to drive down the cost of these developments. That is exactly what Hypersonica is after — bringing this core capability in a sovereign and cost-effective way.
09:56 — Why Maneuverability Is the Hardest Problem
Louise Boucher: You’ve talked publicly about maneuverability being harder than propulsion. Why is it so important, and why is it so hard?
Philipp Kerth: The importance of maneuverability comes from evading interception and unlocking the full capability of a hypersonic system. Let me differentiate from a conventional ballistic missile. Ballistic missiles have existed for decades — since the 1940s and 50s, we’ve been accelerating things to hypersonic speeds. But a ballistic missile is propelled by its booster, climbs on a very high trajectory out of the atmosphere, flies through space, and then falls down onto its target. During re-entry, it reaches hypersonic speeds again. But this trajectory is very predefined — you can’t really modulate it, you can’t really maneuver.
The second issue with a ballistic trajectory is that it goes very high. It’s well above the horizon, so you can detect it early on radar. Because it can’t change its path, a defender has quite a lot of time to put countermeasures in place.
With the new generation of hypersonic missiles, you eliminate both of those disadvantages. Whether it’s a hypersonic cruise missile or a hypersonic glide vehicle, both are accelerated by a solid rocket booster and then separate to start their hypersonic flight in the high atmosphere — a lot lower than a ballistic missile. They come over the horizon much later, and while they fly at hypersonic speeds they remain fully maneuverable. They can change their path, change their target, execute evasion maneuvers. That’s what really causes a step change in strike technology. It makes those systems very survivable — a very high chance of actually hitting the target, and therefore a very efficient way of executing what’s called a deep precision strike.
As for why it’s hard: the hypersonic speed regime is fascinating but very challenging for engineers. The most important issue is temperature. When flying at those speeds, everything gets very hot. You need to deal with that across your entire engineering stack, and you need very high precision, which at those speeds is a real challenge.
Our approach was to rapidly go from concept to test — to compress decision timelines on engineering questions, get data as early as possible, and move forward quickly. We demonstrated that with our first hypersonic test flight, and that is how we are getting from scratch to this capability, tackling all the engineering challenges for maneuverability step by step.
14:20 — Nine Months from Design to Launchpad
Louise Boucher: The test flight was only nine months from design to launchpad. How do you build such a fast-paced culture?
Philipp Kerth: Three key ingredients. First, the right people. Hypersonics has been a niche field for a while. In the 90s, there was still quite a lot of hypersonics research associated with the Space Shuttle program and with the European equivalent — the Hermes glider project. When those were cancelled, hypersonics died down quite a bit. There are very few people actually proficient in making things fly at hypersonic speeds. Marc and I, coming from this research background, became the gravitational center for hypersonics talent and expertise. That is key to developing this technology at pace.
Second, we mixed that hypersonics talent with people who are very proficient at rapidly iterating technology. We looked at where technology has been developed faster and cheaper in highly regulated environments. The new space sector is the clearest example over the last 20 years — timelines and costs got compressed, with SpaceX leading. We brought people from that sector to rapidly iterate from scratch to prototype.
Third, a purpose-built company. You build the company around the technology of hypersonics and around the mission of developing strike systems as rapidly as possible. You end up with really efficient structures focused entirely on this hardware-rich development. That is what allowed us to go this quickly.
16:33 — Building ITAR-Free
Louise Boucher: There’s a sovereignty dimension to how you build, not just what you build. You’ve built an entirely ITAR-free supply chain — no US-controlled components or IP. Was that a deliberate choice from day one?
Philipp Kerth: We’re not trying to replicate what was done in the past or legacy ways of developing these technologies. We’re fundamentally starting on a different operating model and starting with the given reality that we have right now. That reality mandates doing things in an ITAR-free and sovereign way. Very fundamentally, we don’t have 10 years or 10 billion to develop these systems, and we need to do it with a sovereign supply chain.
You need to be able to judge what components work at hypersonic speeds and what don’t — going from first principles, away from any legacy limitations. What enables us to do that is our backbone of hypersonics engineering expertise. For our first test vehicle, all components were sourced ITAR-free, and we’ve been successfully validating that further. In Europe, we do find the skills we need. A lot of research has been done in hypersonics here. There are components we can use from the ITAR-free market, but there are also components we have to pull in-house and redevelop from scratch because nothing on the market will work for this specific hypersonic application. It’s really about doing that back and forth between trade-offs — with ITAR-free as a hard constraint.
Louise Boucher: You’re often compared to Castelion, a US company working on hypersonic and supersonic missiles that’s been growing very fast. Do you even think about competition?
Philipp Kerth: The US startup ecosystem has produced some really impressive companies in the defense space, and Castelion is definitely one of them. The pace at which they’ve developed and tested is impressive and we congratulate them on their success. What is fundamental for us is that we’re a company built around hypersonics and around European sovereignty, European demand, and European requirements. I don’t see the necessity to draw a holistic comparison. We focus on what Hypersonica does.
20:08 — Anglo-German by Design
Louise Boucher: You’re headquartered in Munich, but you’re also a supplier to the UK’s national hypersonic program. How do you navigate the two procurement cultures?
Philipp Kerth: Hypersonica was really built around binational cooperation from the start. Marc and I met at Oxford. Marc spent even more time in the UK than I did — I did four years, he did eight, including his undergraduate studies in London. We were both trained in hypersonics in the UK and are really committed to contributing to that ecosystem.
Between the UK and Germany, there is the Trinity House Agreement, which is a defense cooperation framework that includes deep precision strike as one of its pillars — and hypersonics can be part of that. Very fundamentally, we’re looking to contribute to the ambitions of both countries within that framework.
In terms of what each brings: in the UK, there is hypersonics talent from our group and a national framework that committed several years ago to developing hypersonic strike capability. In Germany, there is strong institutional expertise and a hardware ecosystem in Munich that has given us a great platform to grow. Seeing those two countries develop close ties through Trinity House is particularly helpful for us.
Louise Boucher: Your website also mentions civilian applications — space reentry, faster travel. Is that a genuine long-term vision, or is it more of a dual-use framing?
Philipp Kerth: Hypersonics is absolutely a dual-use technology. Everything we learn about flying faster than Mach 5 in a controlled way contributes well beyond weapons development. It influences space reentry — when capsules come back from orbit and glow as they re-enter the atmosphere, that is exactly the hypersonic speed regime. Anything we develop for better control and heat management can make those reentries more efficient and reduce thermal protection requirements per payload. And eventually, yes, it can contribute to concepts of sustained hypersonic aviation. But those are a bit in the future. We would not pursue aviation concepts in the near term.
We simply see hypersonics as a core technology. Moving at beyond Mach 5 in a maneuverable and precisely controlled way is going to influence a lot of different things — starting with defense, and then certainly spreading into other areas.
24:53 — What Hypersonica Looks Like in Five Years
Louise Boucher: What does Hypersonica look like in four or five years?
Philipp Kerth: The ambition is to be one company concerned with everything that flies faster than five times the speed of sound. The starting point is this: Europe might be behind on a couple of core technologies, but let’s make hypersonics ours. Let’s make this the core technology that first solves our deterrence problem — or at least a large chunk of it — and then moves forward to lead in other areas: space, and maybe at some point aviation. That is the ambition for the company over the next five years.
Louise Boucher: If you’re listening and you’re a great engineer — Hypersonica is hiring. Thanks a lot, Philipp.
Philipp Kerth: Thank you. Awesome.
Kerth’s slide deck still says TBG-style wedge at Mach 7 by 2028. Pentagon pulled same claim in FY20 and quietly slid to 2032 when booster seg faults refused to close. Europe will hit the same wind tunnel queue at AEDC.