**Hop Aero is a venture-backed startup building rockets that deliver cargo anywhere on Earth in minutes.**
Our mission is to enable resilient global logistics to protect and improve our way of life.
Our founding team has prior experience founding a satellite startup and taking it to orbit, launching 20+ Falcon 9 missions at SpaceX, and leading engineering teams at some of the world’s most advanced aerospace organizations. The company is well-capitalized through venture funding and government contracts.
**About the role**
We’re hiring a Lead Hypersonic Reentry Engineer to own the analysis, design, and development of Hop Aero’s atmospheric reentry capability.
This is a foundational technical role spanning hypersonic aerodynamics, aerothermal environments, thermal protection, trajectory trades, vehicle design, testing, and flight-hardware development. You will help define how our vehicles survive high-speed atmospheric flight and repeated reentry while remaining practical, manufacturable, and rapidly reusable.
We’re looking for a broad reentry engineer who can operate across disciplines. You should be comfortable building first-principles models, running CFD, evaluating TPS concepts, working with structures and GNC teams, designing experiments, and using test data to close the loop between simulation and real hardware.
This is not purely a CFD or thermal-analysis role. You will be expected to make vehicle-level engineering decisions, own hardware and test programs, and help take the reentry system from early analysis through flight.
**Job Description**
* Serve as the responsible engineer for hypersonic reentry, aerothermal environments, and thermal-protection systems
* Define vehicle aerodynamic and heating environments across hypersonic entry, atmospheric deceleration, and descent
* Develop first-principles and numerical models for hypersonic aerodynamics, convective heating, radiative heating, and conductive heat transfer
* Perform CFD and other high-fidelity analysis for high-speed atmospheric flight
* Develop aerodynamic and aerothermal databases for use by GNC, structures, propulsion, and vehicle-design teams
* Support trajectory and vehicle-shape trades to balance range, heating, stability, control authority, and structural loads
* Evaluate and select TPS architectures, materials, coatings, insulation systems, and attachment concepts
* Perform coupled aero-thermal-structural analysis to inform vehicle geometry and hardware design
* Assess thermal margins, hot spots, shock interactions, boundary-layer effects, uncertainties, and off-nominal environments
* Define and execute material, coupon, component, and subsystem test campaigns
* Work directly with suppliers and manufacturing teams to develop practical, repeatable reentry hardware
* Correlate analytical models with ground-test and flight-test data
* Develop instrumentation strategies for temperature, heat flux, pressure, strain, and related diagnostics
* Support wind-tunnel, arc-jet, high-enthalpy, and flight-test campaigns as applicable
* Translate reentry environments into requirements for structures, propulsion, avionics, GNC, and vehicle systems
* Own hypersonic reentry technical risks through design reviews, test-readiness reviews, and flight-readiness reviews
* Work in person with the team at our shop in Orange, CA
**Requirements**
* 5-10 years of relevant experience in hypersonics, reentry, high-speed aerodynamics, aerothermal engineering, thermal protection, or closely related fields
* Strong understanding of compressible flow, hypersonic aerodynamics, heat transfer, boundary layers, shock interactions, and high-temperature gas dynamics
* Experience modeling aerodynamic and aerothermal environments for high-speed vehicles
* Experience with CFD and numerical methods for hypersonic or thermally challenging flows
* Experience translating analytical results into vehicle-level design decisions
* Understanding of reentry trajectory trades, vehicle stability, aerodynamic loading, and thermal constraints
* Understanding of thermal-protection materials, insulation systems, structural heating, and thermal interfaces
* Ability to plan experiments, interpret aerodynamic and thermal test data, and correlate models against real measurements
* Ability to work directly with GNC, structures, propulsion, manufacturing, materials, and test teams
* Willingness to be hands-on with test articles and flight hardware
* **Must be a US Person under ITAR - _Hop Aero will not sponsor visas for this role._**
**Nice to have**
* Experience with atmospheric reentry vehicles, hypersonic vehicles, launch vehicles, missiles, or spacecraft
* Experience developing reusable reentry or thermal-protection systems
* Experience with arc-jet, plasma, wind-tunnel, shock-tunnel, or other high-enthalpy testing
* Experience with ceramic, metallic, ablative, or composite TPS materials
* Experience with coupled CFD/FEA or conjugate heat-transfer analysis
* Experience developing aerodynamic or aerothermal databases across large flight envelopes
* Experience with hypersonic trajectory optimization or vehicle-shape optimization
* Experience taking reentry hardware from analysis through ground test and flight
* Experience on DoD or U.S. Air Force high-speed flight programs
* Prior experience at a fast-moving aerospace or hardware startup
**What we offer**
* Competitive salary and meaningful stock options
* Healthcare, office meals & snacks
* Direct collaboration with founders & engineers with rich flight heritage
* Significant technical ownership from day one
* The opportunity to define the hypersonic reentry architecture of a new class of reusable vehicle
* Fast upward mobility as the company grows
**Even if you don’t meet every single requirement, we’d still love to hear from you. Greatness looks different in every one of us - and we need the best tackling this problem.**
Visa sponsorship is not available for this role.
