Hermeus Corporation is a private aerospace company pushing the boundaries of hypersonic aircraft technology. They’re developing planes that can fly faster than Mach 5.
Based in Atlanta, Hermeus focuses on both commercial passenger travel and military uses. The leadership team includes aerospace industry veterans who know their stuff.
Hermeus wants to change air travel forever by building hypersonic aircraft that can hit Mach 5 and beyond. Imagine crossing continents in a couple of hours.
They’re going after two markets at once. Halcyon is their vision for a hypersonic passenger jet, while Darkhorse is an uncrewed military aircraft they plan to mass-produce.
Their technology could completely shake up both civilian and military aviation. They’re aiming to cut flight times dramatically on long routes.
Hermeus claims their Quarterhorse aircraft will cover 4,600 miles at Mach 5. That’s wild.
The U.S. Air Force has shown real interest in what Hermeus is doing, even considering it for future Air Force One missions. That kind of support says a lot about Hermeus’ technical direction and pace.
Four aerospace professionals started Hermeus Corporation in 2018. AJ Piplica leads as CEO, steering strategy and daily operations.
Skyler Shuford is the Chief Operating Officer, handling R&D, system analysis, testing, growth, and planning for certifications. He’s got a lot on his plate.
Glenn Case takes care of hypersonic propulsion development as CTO. Mike Smayda acts as Chief Product Officer, managing product and engineering programs.
These founders bring deep aerospace experience from avionics to software and advanced propulsion. They’ve done this before.
Hermeus calls Atlanta, Georgia home. They run operations out of four different sites to keep their projects moving.
Flight tests happen out at Edwards Air Force Base in California. In May 2025, Hermeus pulled off successful Quarterhorse Mk 1 flight tests there.
They’ve raised big money to keep growing. In March 2022, Hermeus landed $100 million in Series B funding, led by Sam Altman.
Other investors include Founders Fund, In-Q-Tel, Khosla Ventures, Canaan Partners, and Bling Capital. The U.S. Air Force chipped in $60 million in 2021 to help with Quarterhorse testing.
That government support keeps their hypersonic tech moving forward.
Hermeus has built solid partnerships with major aerospace companies and attracted some big-name investors. Sam Altman and others have backed them, and they’ve teamed up with defense contractors like Raytheon Technologies.
Raytheon Technologies, via RTX Ventures, invested strategically in Hermeus. This partnership connects Hermeus with one of the top defense contractors in the country.
Raytheon brings Hermeus access to aerospace know-how and manufacturing muscle. RTX Ventures looks for technologies that fit both defense and commercial aviation.
By teaming up, Hermeus can lean on Raytheon’s relationships with government agencies. Raytheon’s decades in advanced aircraft and military systems don’t hurt either.
Wachtell, Lipton, Rosen & Katz represented Raytheon in the deal. The partnership shows established aerospace players believe in hypersonic tech.
Hermeus closed a $100 million Series B funding round led by Sam Altman. Founders Fund and In-Q-Tel, which invests for U.S. intelligence agencies, also participated.
Key Investors Include:
Altogether, Hermeus has raised $239 million over several rounds. Their latest round brought in $40 million in June 2024.
In-Q-Tel’s involvement signals strong government interest in what Hermeus is building. They usually back tech with national security value.
Hermeus has lined up several partnerships with the Department of Defense. These include Air Force contracts worth $60 million, projects with the Defense Innovation Unit, and work on advanced aircraft for executive transport.
The Air Force awarded Hermeus a $60 million contract in July 2020 to test the Quarterhorse aircraft. That’s a major investment in commercial hypersonic development.
The contract aims to speed up hypersonic technology through lots of real-world testing. Quarterhorse is the main testbed for proving out these new technologies.
The Air Force Research Laboratory added more funds with smaller contracts, targeting things like propulsion integration and thermal management.
This partnership also gives Hermeus access to Edwards Air Force Base for testing. That’s a huge deal for high-speed aircraft validation.
In November 2023, the Defense Innovation Unit gave Hermeus a multi-year contract under the Hypersonic and High-Cadence Airborne Testing Capabilities (HyCAT) program. The goal? Boost the DoD’s high-speed flight test capacity using commercial tech.
The contract targets four areas:
Hermeus will show off these technologies using the Quarterhorse platform. The program shifts commercial aircraft capabilities into real military flight test services.
This partnership helps close the gap between experimental tech and operational hypersonic aircraft. It’s a more flexible, risk-reducing way to speed up development.
The Air Force also gave Hermeus $1.5 million to study hypersonic military transports. They’re looking at a 9-19 seat aircraft for executive missions.
This effort explores reusable hypersonic aircraft for moving key personnel fast across the globe.
The work involves analyzing what’s needed for executive airlift using hypersonic tech—flight profiles, seating, and mission capabilities all get a close look.
Hermeus drives its hypersonic aircraft program with quick iteration and bold speed goals. They’re aiming for Mach 5 capabilities by testing more advanced prototypes step by step.
Hermeus is all about building planes that can go faster than Mach 5—over twice as fast as the Concorde ever flew. Their main project, Quarterhorse, is designed to hit Mach 5 and cover 4,600 miles.
The tech roadmap revolves around the in-house Chimera engine. Hermeus says they’ve already tested it at Mach 5 in prototype form. That’s a huge step toward real hypersonic flight.
They run most of their engineering and manufacturing from a 110,000-square-foot facility in Atlanta. Their Jacksonville site, the High Enthalpy Air-breathing Test (HEAT) center, is where they put engines through their paces—from F100s to Chimera.
They’re working on both crewed and uncrewed versions. The defense side leans uncrewed for security missions, while the commercial side targets passenger transport at speeds we’ve only dreamed about.
The Quarterhorse Mk 1 prototype took its first successful flight in May 2025 at Edwards Air Force Base. That was a big moment for Hermeus, proving they can move fast—just 20 months from project kickoff to flight.
From design completion to actual flight, they only needed 204 days. That kind of speed is rare these days, maybe not seen since the 1950s.
Hermeus has plenty of funding for more testing. The US Air Force gave them a $1.5 million contract in August 2020 for aircraft development. In total, venture capital and Air Force investments have reached $60 million for the hypersonic program.
Next up, they’re planning a Mach 3 prototype by the end of 2025. That’s the next big step toward full Mach 5 capability.
Flight testing happens mostly at Edwards, while the Jacksonville HEAT facility handles ground engine tests—safer and more controlled.
The Quarterhorse program is Hermeus’ structured path to hypersonic flight, using a series of increasingly advanced test vehicles. They started with the Mk 0 for ground testing, moved to Mk 1 for flight, and have bigger plans for even faster aircraft.
Quarterhorse Mk 1 is Hermeus’ main flight test platform for hypersonic technology. This uncrewed aircraft completed its first flights at Edwards Air Force Base in California—definitely a key milestone.
The aircraft uses Rogers Dry Lake’s huge runway system. Edwards is perfect for this type of testing with its 6.2-mile-long lakebed runway and all the right facilities.
Hermeus built the Mk 1 to move fast and gather real data. They prefer hardware-in-the-loop testing over endless simulations, so engineers get feedback quickly.
Key Design Features:
The Mk 1 builds on what they learned from the Mk 0 ground vehicle, which hit all its goals in just six months from design to test wrap-up.
The Quarterhorse program is where Hermeus proves out its turbine-based combined cycle (TBCC) engine. This engine blends a traditional turbojet with advanced hypersonic propulsion.
They started with a modified GE J85 turbojet for reliability at lower speeds, then layered in systems for Mach 5 and up.
The U.S. Air Force put $60 million into flight testing this engine tech. Through the AFWERX Strategic Funding Increase program, the military is betting on Hermeus’ approach.
Engine Testing Phases:
The TBCC setup lets the engine work from takeoff all the way to hypersonic cruise. Unlike scramjets, which only operate at high speeds, this approach covers the whole flight envelope.
The Quarterhorse program tackles both commercial and defense needs. NASA jumped in as a partner back in 2021, eyeing the potential for civilian transportation, while the Air Force zeroed in on military hypersonic capabilities.
Commercial Applications:
If Mach 5 flight becomes reality, flight times would absolutely plummet. Imagine New York to London in just 90 minutes instead of slogging through a seven-hour trip—hard to picture, but that’s the promise.
The team behind Quarterhorse wants to break the SR-71 Blackbird’s legendary airspeed record. They’re rolling out four variants, each one pushing the envelope a bit further, until they finally hit that milestone.
Hermeus believes Mach 5 aircraft could add a staggering four trillion dollars to the global economy every year. That kind of growth would come from faster business, more trade, and whole new industries built around rapid transportation.
They’ve taken a different approach than the typical aerospace giants. By using autonomous systems, focusing development goals, and embracing controlled failure during testing, they move faster and keep costs down.
The Darkhorse program is Hermeus Corporation’s next-level hypersonic aircraft effort, taking what they learned from Quarterhorse and building on it. This new, uncrewed system is all about military and national security, promising Mach 5 speeds and the freedom to operate without a runway.
The Darkhorse hypersonic aircraft can hit Mach 5, thanks to its Chimera II engine system. This turbine-based combined cycle engine uses the proven Pratt & Whitney F100-229 turbofan at its core.
That F100 engine delivers some serious punch. With 29,000 pounds of thrust and over 30 million flight hours under its belt from F-15s and F-16s, it’s got quite a track record.
Key Performance Features:
This aircraft stands out from rocket-based hypersonic vehicles because you can reuse it. Rockets need specialized launch infrastructure and you can’t fly them again—once they’re gone, they’re gone.
Darkhorse keeps things flexible by launching from runways. Military bases don’t need to build new facilities or mess with rocket boosters to deploy it.
Defense and national security really drive the Darkhorse program. The aircraft meets tough military needs for rapid response and survivable reconnaissance.
Intelligence gathering is a big focus here. With its speed and altitude, Darkhorse can slip into contested airspace and grab time-sensitive data.
Mission Categories:
The design adapts to different payloads. Mission planners can tweak the aircraft for whatever the job calls for, without a total overhaul.
Military leaders appreciate how tough it is to shoot down. At these speeds and altitudes, enemy defenses have a hard time tracking and engaging the aircraft.
Hermeus kicked off engine testing in 2024, starting with the F100 integration. They set up specialized facilities to put the Chimera II propulsion system through its paces.
Their Jacksonville facility handles hypersonic engine development and testing. Hermeus broke ground there in September 2024 to speed things up.
They hit a big milestone in January 2025 by launching the HEAT testing facility. This place lets them run full engine tests under flight-like conditions.
Development Phases:
The program needs FAA airworthiness certification before they can start commercial testing. That certification makes sure the aircraft is safe for defense contractor work.
Hermeus works closely with the Air Force and other defense agencies during development. The company secured $60 million in Air Force funding to help with flight tests and system validation.
Hermeus builds propulsion systems that blend turbojet and ramjet tech to push into hypersonic territory. They’re really focused on thermal management and pre-cooler systems to handle the heat.
The Chimera engine is Hermeus’ big propulsion breakthrough. It’s a turbine-based combined cycle (TBCC) system, merging classic turbojet tech with ramjet power.
They start with a Pratt & Whitney F100 engine. This military workhorse gives the initial thrust for takeoff and acceleration to supersonic speeds.
Once the plane gets going fast enough, ramjet components kick in. That shift lets the aircraft blast past Mach 5. With this dual-mode setup, they don’t need separate propulsion systems.
The improved Chimera II builds on what they learned in earlier tests. This version will drive the Darkhorse program.
Engineers run tests at the High Enthalpy Air-breathing Test (HEAT) facility in Jacksonville, Florida. They test everything from individual parts to full engine systems there.
Flying this fast creates insane heat that can wreck aircraft parts. Hermeus engineers design special cooling systems to keep engines safe.
They use materials that handle temperatures over 2,000 degrees Fahrenheit. These materials keep their strength during long hypersonic flights.
Active cooling circuits move coolant through engine parts. This setup protects turbine blades and combustion chambers from heat damage.
Heat exchangers reclaim waste heat, boosting engine efficiency and cutting fuel use.
The thermal protection systems go beyond the engine, shielding the airframe and electronics from heat during flight.
Pre-coolers chill the incoming air before it hits the engine, making hypersonic speeds possible.
Heat exchangers in the pre-cooler drop the temperature of compressed air. Cooler air keeps engines efficient and stops parts from frying.
This technology lets turbojet parts work at higher speeds. Without it, regular jet engines just can’t keep up at Mach 5.
Engineers have to balance cooling power with weight. They fine-tune heat exchanger size so the aircraft doesn’t get too heavy.
Managing airflow and keeping the system reliable are big challenges. The pre-cooler has to run nonstop during hypersonic flight, with no room for breakdowns.
Hermeus blends autonomous tech with modern computing to build hypersonic aircraft that don’t need pilots. They mix artificial intelligence with hands-on hardware development, aiming for true autonomous flight at extreme speeds.
Hermeus bakes autonomy in from the start. The Quarterhorse program shows this off with reusable, autonomous aircraft that can almost hit Mach 5.
Their hardware-heavy development style lets them test autonomous systems quickly. Every prototype checks off different pieces of the autonomy puzzle. The Quarterhorse Mk 1 even pulled off autonomous takeoff and landing at Edwards Air Force Base.
Key autonomous features include flight path management, speed control, and landing. These systems have to work at hypersonic speeds—no way a human could keep up.
The Darkhorse program is Hermeus’s uncrewed hypersonic aircraft, built for defense. No humans on board means it can pull off maneuvers and maintain speeds that would be way too dangerous for a pilot.
Modern computers let Hermeus aircraft process flight data on the fly. They pack advanced AI algorithms into the flight systems, making the platforms super responsive.
AI handles flight control and mission tasks. These systems read the environment, tweak flight settings, and react to new situations—all without a person in the loop.
Mixing AI with hypersonic propulsion isn’t easy. The AI has to process data fast enough to control a plane screaming along at Mach 5. Split-second decisions are the norm.
Machine learning algorithms help boost flight performance in all kinds of conditions. The AI learns from each test, making the next flight even smoother. This cycle speeds up the path to reliable autonomous hypersonic flight.
Hermeus runs advanced testing facilities to push hypersonic aircraft development forward. Their HEAT facility in Florida handles ground testing, while flight test programs take prototypes to the skies.
Hermeus opened its High Enthalpy Air-Breathing Test Facility (HEAT) at Cecil Airport in Jacksonville, Florida in January 2025. This spot fills a big gap in U.S. hypersonic test infrastructure.
HEAT wrapped up its first phase in just three months. The whole project cost a tenth of what similar facilities do, and took a fraction of the time. That speed means Hermeus can offer cheaper testing than most.
They repurposed buildings from the old Cecil Naval Air Station, including test cells from 1959 and a hush house from 1989. Hermeus added custom fuel systems, air starts, and data gear.
Current Testing Capabilities:
Future upgrades will add continuous high-Mach vitiated airflow. That’ll make ground testing way more realistic for hypersonic vehicles. The facility is set to become a national hub for hypersonic projects.
Hermeus flies test missions from several sites around the U.S. They team up with existing test centers to keep their development moving.
The Quarterhorse Mk 1 showed how fast they can move by getting into flight tests quickly. Edwards Air Force Base’s Experimental Test Force helped with airworthiness checks, keeping things safe and efficient.
Starting in 2026, Cecil Airport will become Hermeus’s main flight test base. The site offers restricted airspace and solid aviation infrastructure. It’ll host high-speed flight tests for their advanced prototypes.
Flight Test Aircraft:
Hermeus plans to invest $135 million in testing infrastructure. That investment should create more than 100 jobs over the next decade and build out national hypersonic testing capabilities.
Hermeus’s hypersonic aircraft could totally change commercial aviation—think flights under 90 minutes, no matter where you’re going on Earth. Making this work will mean completely rethinking air traffic control and airport design to handle planes zipping around at Mach 5 and beyond.
Hermeus wants to build passenger aircraft that can hit speeds over 3,800 miles per hour. That would mean flying from New York to London in just 90 minutes instead of slogging through a 7-hour flight.
The first planes will probably carry about 20 passengers. These jets will cruise above 60,000 feet, soaring well above today’s commercial traffic. Passengers might even get a brief taste of weightlessness during takeoff and landing.
But, let’s be honest, Hermeus still has a mountain to climb before anyone can buy a ticket. The jets have to survive the insane heat hypersonic speeds create. Engineers need to rethink cabin pressurization from the ground up for those altitudes.
Tickets won’t be cheap at first—think $100,000 per seat. As they build more planes and the tech improves, prices should drop. Early customers will probably be business travelers or curious, wealthy tourists who value time over money.
Getting safety certification from aviation authorities is the biggest challenge. No one’s ever managed to get a hypersonic passenger plane approved for regular flights.
Today’s air traffic control systems just can’t keep up with hypersonic jets. Ground radar would need a serious upgrade to track planes zipping across time zones in minutes.
Airports would have to redesign parts of their infrastructure for these flights. Runways might need to be longer for takeoff and landing, and ground crews would need equipment that can handle the heat from those engines.
Controllers would need fresh training to handle flights that cross continents in under two hours. The old ways of keeping planes separated just won’t cut it. Communication systems would also have to adapt to the rapid altitude and position changes.
Hermeus plans to fly in corridors above regular commercial jets, which sounds cool but brings new headaches for airspace management. International coordination gets tricky when a jet can cross several countries in a matter of minutes.
The Federal Aviation Administration has started early talks about how to regulate hypersonic jets. New certification rules will have to address unique safety considerations for these kinds of flights.
Hermeus faces a complicated web of FAA compliance requirements for testing hypersonic aircraft. They also have to deal with strict export control laws on advanced propulsion technologies.
The FAA has set up special exemption processes for Hermeus’ experimental aircraft. Hermeus submitted petition FAA-2024-2728, asking for relief from some Federal Aviation Regulations so they can test their Quarterhorse Mark 1 unmanned aircraft.
Hermeus works with the 412th Test Wing engineers at Edwards Air Force Base to get airworthiness certifications. This partnership lets them prove their flight systems are safe.
Right now, civil aviation doesn’t really have a full set of rules for hypersonic jets. The current standards just weren’t made for vehicles hitting extreme temperatures and speeds like these.
Key compliance areas include:
Airports will need to upgrade their infrastructure for hypersonic jets. Ground support systems have to handle extreme temperatures and unique fuel needs.
Hermeus operates under tough International Traffic in Arms Regulations (ITAR). Their hypersonic tech falls under dual-use export controls because of its military potential.
They have to keep detailed records for any foreign nationals who access technical data. Manufacturing sites need security clearances and tight access controls.
Export control compliance includes:
The Defense Department keeps an eye on Hermeus’ military partnerships. Hermeus coordinates with the Air Force Research Lab but still pushes their commercial development.
The State Department requires licenses for any international work on hypersonic tech. These rules can slow things down and limit who Hermeus can work with for critical parts.
Hermeus seems ready to shake up high-speed travel with its hypersonic aircraft and defense partnerships. They’ve raised $239 million and built up some serious manufacturing capabilities.
Hermeus has grown fast, opening a 110,000 square foot manufacturing facility and building a dedicated test site from scratch. In just a year, they doubled their workforce and ran over 100 engine tests.
The $100 million Series B round, led by Sam Altman, gives them the cash to keep pushing forward. Investors like Founder’s Fund and In-Q-Tel joined existing backers such as Khosla Ventures and Canaan Partners.
Key expansion milestones include:
The facility expansion helps them balance defense contracts and commercial projects. That dual focus gives them revenue stability while they push the envelope on hypersonic tech.
Hermeus has already tested its proprietary Mach 5 engine, Chimera. They’ve built and flown a full-scale prototype and are working on autonomous systems for government uses.
The Quarterhorse aircraft marks their next big step in flight testing and proving their tech. This platform will show off hypersonic speeds beyond Mach 5.
Technical development priorities:
They use a “hardware richness” philosophy, which basically means they build and test a lot, fast. This helps them spot problems early and see how their designs perform in real life.
Hermeus brings private investment into hypersonic development, a field that used to rely mostly on government money. Hundreds of millions in private funding are now pushing this tech forward.
Working with government agencies opens early markets and gives them a chance to test and prove their tech. Defense contracts provide cash and flight test opportunities that help them get better, faster.
Industry impact areas:
If hypersonic passenger travel takes off, we could see Atlantic crossings in 90 minutes. That’s a game-changer, with massive economic potential from faster travel and better global connections.
People keep asking about Hermeus’ timeline for commercial flights, their military ties, the founding team, and the possibility of a stock offering. As a private aerospace firm tackling hypersonic tech for both defense and civilian use, they’ve got some unique challenges.
Hermeus hasn’t given a firm date for commercial passenger flights. Right now, they’re focused on developing and testing their hypersonic aircraft, like the Quarterhorse program.
Commercial flights probably won’t start until several years after they finish their flight tests. They need to prove the tech is safe and reliable for government contracts before moving into civilian markets.
Hypersonic travel faces huge regulatory hurdles. Aviation authorities still need to create new safety standards and certification processes for jets flying faster than Mach 5.
Quarterhorse is Hermeus’ main flight test vehicle for hypersonic tech. The U.S. Air Force put $60 million into this program back in 2021.
This aircraft lets Hermeus test systems and collect real flight data. Engineers use what they learn to improve future designs, both for commercial and military projects.
Quarterhorse proves Hermeus can actually build and fly hypersonic vehicles. Success here helps them land more government contracts and attract private investors.
AJ Piplica is the current CEO of Hermeus. The company was started in 2018 by a team with aerospace engineering backgrounds.
They haven’t shared a ton of details about every founder or their full work histories. The team brought experience from other aerospace and defense tech companies.
Hermeus tends to keep leadership bios private. They usually focus public updates on their technology and business partnerships.
The Department of Defense is a main customer for Hermeus’ hypersonic aircraft. Military uses include rapid personnel transport and fast cargo delivery across the globe.
Hypersonic jets could move troops between bases in hours, not days. That gives the military a big advantage for operations and emergencies.
Allied nations are also interested in Hermeus’ tech for defense. International military customers could help Hermeus grow beyond just U.S. contracts.
Hermeus looks for engineers with backgrounds in aerospace, propulsion, and materials science. They need experts in hypersonic flight dynamics and advanced manufacturing.
Software engineers who know flight control systems and avionics are in demand too. As they get closer to flight testing, they’ll need more test pilots and operations staff.
Hermeus is based in Atlanta, Georgia, but has employees on multiple continents. Depending on the project, some technical roles might offer remote work options.
Hermeus is still a privately held company. They haven’t shared any official timeline for an IPO yet.
Back in March 2022, the company raised $100 million in Series B funding, with Sam Altman leading the round. You’ll find investors like Khosla Ventures, Founders Fund, and In-Q-Tel on board as well.
Right now, only accredited investors can buy shares through secondary market platforms. That might change if Hermeus ever goes public.
The company wrapped up its latest funding round in July 2024. In this industry, it’s pretty common for aerospace startups to stay private for years while they work on tough tech challenges.
