Hermeus

APrivateFounded 2018🇺🇸El Segundo, California

CEO

Zach Shore

Data verified as of Jul 18, 2026

Summary

Hermeus is a defense aviation company focused on rapidly designing, building, and flight-testing high-Mach and hypersonic aircraft for national-security missions. Its Quarterhorse program is progressing through a series of unmanned demonstrators to unlock high-speed flight — Mk 2.1 reached Mach 1.21 on May 26, 2026 in its third flight from Spaceport America, becoming the first privately-developed unmanned supersonic jet — and the Chimera engine architecture underpins Darkhorse, the reusable hypersonic UAS Hermeus aims to field for defense customers. The company is now backed by a $1B post-money valuation, a $350M Series C closed in April 2026, and a Defense Innovation Unit contract scaled to a $219M ceiling in late May 2026 to demonstrate high-Mach flight and high-speed payload release at speeds up to Mach 3. In a May 2026 leadership transition effective June 1, 2026, president Zach Shore became CEO while co-founder AJ Piplica moved to executive chairman.

Main Products

Quarterhorse

In Flight Testing (Supersonic)

An iterative program of unmanned, remotely piloted test aircraft designed to unlock high-speed flight one step at a time. Hermeus says the Quarterhorse program spans four aircraft, each purpose-built to validate a specific technical challenge and feed the next build.

Mk 1 flew at Edwards AFB in May 2025. Mk 2.1, roughly F-16-sized and powered by a Pratt & Whitney F100, flew in February 2026 and on its third flight from Spaceport America hit Mach 1.21 on May 26, 2026, becoming the first privately-developed unmanned supersonic jet and clearing FAA approval for up to seven supersonic flights through year-end. Hermeus says Mk 2.2 is in build and targeted to reach Mach 1.6 in summer 2026, with Mk 2.3 aiming for Mach 3 in 2027 and a Chimera-powered hypersonic Mk 3 before 2030.

Program Vehicles4

Mk 2.1 EnginePratt & Whitney F100

Mk 2.1 Top SpeedMach 1.21 (~930 mph) on third flight, May 26, 2026

Successful First Flights2 (Mk 1, May 2025; Mk 2.1, February 2026)

FAA Supersonic Authorization (Mk 2.1)Up to 7 supersonic flights through end of 2026

Darkhorse

In Development

A multi-mission reusable hypersonic uncrewed aerial system (UAS) designed for defense and national security missions including ISR and strike in contested environments. Powered by the Chimera II TBCC engine.

Darkhorse remains the defense product Hermeus is building toward as Quarterhorse expands the validated flight envelope and Chimera II matures around the Pratt & Whitney F100 core.

Target SpeedMach 5 (~3,300 mph)

EngineChimera II TBCC (P&W F100 + ramjet)

Aircraft TypeReusable hypersonic UAS

Halcyon

Conceptual

A planned Mach 5 commercial hypersonic airliner that would carry approximately 20 passengers at 90,000+ feet altitude, cutting transatlantic flight times from 7 hours to 90 minutes. Represents Hermeus's long-term commercial vision.

Still a long-term aspiration rather than a near-term program. Hermeus is currently prioritizing defense aircraft, Quarterhorse flight testing, and propulsion maturation.

Target SpeedMach 5 (~3,300 mph)

Passenger Capacity~20

Range~4,600 miles

Example RouteNYC → London in 90 minutes

What's Next

Expand Mk 2.1 envelope toward Mach 3 by 2027

With supersonic flight achieved on May 26, 2026 and FAA clearance in hand for up to seven supersonic flights through year-end, Hermeus's next gate is steadily widening Mk 2.1's envelope toward Mach 3 in 2027 while bringing Mk 2.2 and Mk 2.3 online to push higher in the high-Mach regime. As of early July 2026 Mk 2.1's top speed remained Mach 1.21 and Mk 2.2 had not yet flown.

2027

Execute DIU $219M high-Mach payload-release demos

The May 2026 $159M DIU contract modification — taking the program ceiling to $219M — commits Hermeus to a series of intensive 2026-2027 flight tests with the USAF and USN proving uncrewed Quarterhorse can hold high-Mach speeds while carrying and releasing payloads, the technical foundation for a Darkhorse-class operational system.

2026-2027

Bring Mk 2.2 and Mk 2.3 online

Hermeus says the new financing lets it run a fleet of three F-16-scale Quarterhorse aircraft and begin customer payload integration rather than iterating one airframe at a time. Mk 2.2 is in build and targeted to fly to Mach 1.6 in summer 2026, with Mk 2.3 aiming for Mach 3 in 2027.

2026-2027

El Segundo HQ ramp and Atlanta production scale-up

The ~62,550 sq ft El Segundo headquarters at 888 North Douglas (a former Northrop Grumman campus) is expected to add more than 200 jobs over the next year as executive, design, and prototyping teams consolidate in California, with full occupancy expected in early 2027; the 175-person Atlanta facility is shifting toward production-rate assembly work for the growing Quarterhorse fleet.

2026-2027

HEAT engine test facility completion

The High Enthalpy Air-breathing Test (HEAT) facility at Cecil Airport in Jacksonville — a ~$135M investment expected to create 100+ jobs over the decade — is being built in phases toward continuous high-Mach vitiated-air ground testing of the F100 and Chimera engines. Hermeus has said services should begin scaling in 2026, and the site is also intended to base high-Mach Quarterhorse flight-test operations into the Eastern Range.

2026-2027

Recent News

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Jun 17

Hermeus names Zach Shore CEO; founder Piplica becomes chairman

Hypersonic aircraft developer Hermeus appointed Zach Shore as chief executive officer effective June 1, with founding CEO AJ Piplica transitioning to executive chairman. The leadership change comes as Hermeus advances its uncrewed Quarterhorse Mk 2.1 — billed as the world's first privately developed unmanned supersonic jet, which has flown to Mach 1.21 — and develops the larger Darkhorse, for which it has accepted its first Pratt & Whitney F100 engine to integrate into its Chimera II turbine-based combined cycle propulsion system. The company has won a $159 million Defense Department contract exploring military applications of its high-speed technology.

May 30

Hermeus Quarterhorse becomes first private unmanned supersonic jet

Hermeus said its Quarterhorse Mk 2.1 test aircraft hit Mach 1.21 (~930 mph) on its third flight from Spaceport America over the White Sands Missile Range, making it the first privately-developed unmanned aircraft to break the sound barrier and, by Hermeus's claim, the fastest unmanned jet flying today. The milestone came 364 days after Hermeus's Mk 1 maiden flight and roughly three months after Mk 2.1's first flight, validating the iterative build cadence behind the company's path to its Mach 5 Darkhorse military UAS.

Operations & Revenue

StatusDevelopment Stage

Quarterhorse Mk 2.1 broke the sound barrier at Mach 1.21 from Spaceport America on May 26, 2026 — Hermeus's third Quarterhorse flight overall and the first privately-developed unmanned supersonic jet — and Mach 1.21 remains its top speed as of early July 2026. The FAA has cleared up to seven supersonic flights for Mk 2.1 through year-end; Mk 2.2 remains in build and has not yet flown (Hermeus has framed it as targeting a world-record unmanned speed in summer 2026), with Mk 2.3 to follow. The DIU contract was scaled to a $219M ceiling in late May 2026 to fund high-Mach flight and high-speed payload-release demonstrations across 2026-2027, with the Atlanta plant shifting to production and prototyping consolidating at the new El Segundo HQ under CEO Zach Shore (effective June 1, 2026).

Revenue Streams

U.S. Government Contracts

Hermeus' near-term business is centered on U.S. government and national-security work while it matures Quarterhorse, Darkhorse, and its propulsion stack.

Darkhorse Military UAS (future)

Potential future program revenue from Darkhorse, a reusable hypersonic unmanned aircraft for defense and national-security missions. Technology is being de-risked through Quarterhorse and Chimera II development.

Halcyon Commercial Airliner (future)

Long-term passenger-aircraft opportunity built around the same high-speed technology stack. It remains secondary to the company's defense aircraft roadmap.

Key Metrics

Employees

~300

Est. Annual Revenue

Undisclosed (development stage); $219M DIU program ceiling for high-Mach flight + payload-release demos

Total Capital Raised

>$500M

Post-Money Valuation

$1B

Employees

~300 (175 in Atlanta + LA scale-up)

Quarterhorse First Flights

2 (Mk 1 in May 2025, Mk 2.1 in February 2026)

Quarterhorse Top Speed

Mach 1.21 (Mk 2.1, May 26, 2026)

DIU Contract Ceiling

$219M (after May 2026 $159M modification)

Timeline

2026Quarterhorse Mk 2.1 first flight

The F-16-sized Quarterhorse Mk 2.1 completes its maiden flight at Spaceport America, giving Hermeus its second successful first flight in less than a year and opening a supersonic flight-test campaign.

2026FAA clears Quarterhorse Mk 2.1 flight campaign

The FAA grants Quarterhorse Mk 2.1 a Special Airworthiness Certificate in the experimental category, allowing Hermeus to continue progressively higher-altitude and higher-speed testing toward supersonic flight.

2026$350M Series C and new El Segundo HQ

Hermeus closes a $350M Series C financing that brings total capital raised to over $500M and says it will expand its prototyping footprint with a new headquarters in El Segundo while shifting the Atlanta site toward production.

2026Quarterhorse Mk 2.1 breaks the sound barrier

On its third test flight from Spaceport America over the White Sands Missile Range on May 26, 2026, Quarterhorse Mk 2.1 reaches Mach 1.21 (~930 mph), becoming the first privately-developed unmanned supersonic jet and, per Hermeus, the fastest unmanned aircraft flying today. The flight comes 364 days after Mk 1's maiden flight and roughly three months after Mk 2.1's first flight.

2026DIU contract scaled to $219M for high-Mach payload demos

Two days after the supersonic milestone, Hermeus announces on May 28, 2026 a $159M modification from the Defense Innovation Unit that raises the program's total ceiling to $219M — one of the largest awards in DIU history. Together with the U.S. Air Force and U.S. Navy, the company commits to a series of intensive 2026-2027 flight tests demonstrating high-Mach flight and high-speed payload release with the Quarterhorse family.

2026Zach Shore named CEO; Piplica becomes executive chairman

On May 11, 2026 Hermeus announces a leadership transition effective June 1, 2026: president Zach Shore becomes chief executive officer while co-founder AJ Piplica moves to executive chairman, where he focuses on capital strategy, the board, and investor and customer relationships as the company scales Quarterhorse flight testing toward production.

2025Quarterhorse Mk 1 first flight

The Quarterhorse Mk 1 completes its maiden flight at Edwards Air Force Base, marking Hermeus's first successful flight test.

2022$100M Series B and ABMS selection

Hermeus raises $100M led by Sam Altman with Founders Fund and In-Q-Tel. The company is selected for the USAF Advanced Battle Management System (ABMS) contract with a $950M ceiling.

2022Chimera turbojet-to-ramjet transition achieved

The Chimera turboramjet engine successfully transitions from turbojet to ramjet mode during testing at the Notre Dame Turbomachinery Lab, a critical milestone for Mach 5 propulsion.

2021NASA Space Act Agreement

Hermeus signs a Space Act Agreement with NASA for collaborative research on high-speed aircraft technologies.

2021$60M USAF Quarterhorse contract

The U.S. Air Force awards Hermeus a $60M contract to build and fly three Quarterhorse prototype aircraft and develop reusable hypersonic propulsion technology.

2020Chimera engine prototype demonstrated

Hermeus demonstrates a subscale Chimera engine prototype, validating the turbojet-to-ramjet transition concept that is core to its Mach 5 propulsion strategy.

2020First USAF contract

The U.S. Air Force awards Hermeus a $1.5M SBIR Phase II contract to study a Mach 5 aircraft concept for Presidential and Executive Airlift.

2018Founded

AJ Piplica, Glenn Case, Mike Smayda, and Skyler Shuford found Hermeus in Atlanta, Georgia, with the mission of radically accelerating air travel through hypersonic flight.

Funding

Cumulative disclosed raise · dated rounds

Round	Date	Amount	Investors
Seed	2019	Undisclosed	Khosla Ventures
Series A	2020	$16M	Canaan Partners, Khosla Ventures, Bling Capital
Series B	2022	$100M	Sam Altman, Founders Fund, In-Q-Tel, Khosla Ventures, Canaan Partners
Series C	2026	$350M	Khosla Ventures-led; continued backing from Canaan Partners, Founders Fund, RTX Ventures, Bling Capital, and In-Q-Tel, plus new investors including Cox Enterprises/Socium Ventures and Destiny Tech100; financing also includes debt capital from Silicon Valley Bank, Pinegrove Venture Partners, Hercules Capital, and Trinity Capital
USAF Contract	2021	$60M	U.S. Air Force
DIU Contract Extension	May 2026	$159M modification (program ceiling $219M)	Defense Innovation Unit (with USAF and USN partners)