Senior Propulsion Test Engineer at Hermeus – Jacksonville, Florida

Senior Propulsion Test Engineer

Hermeus is a high-speed aircraft manufacturer focused on the rapid design, build, and test of high-Mach and hypersonic aircraft for the national interest. Working directly with the Department of Defense, Hermeus delivers capabilities that will ensure that our nation, and our allies, maintain an asymmetric advantage over any and all potential adversaries.
At Hermeus, we are constantly iterating and integrating. We test early and often to minimize technical and program risk. We build the test infrastructurethat supports our full range of test programs spanning development, operational and certification testing. Hermeus is seeking a Senior Propulsion Test Engineer to support the development, integration, and operation of propulsion test systems at our Florida facility. This is a hands-on, high-impact role focused on building test capabilities and executing test campaigns for next-generation hypersonic propulsion systems. You will work closely with engineers and technicians across multiple disciplines to design test hardware, operate complex test facilities, and ensure safe, reliable, and repeatable performance. This role is ideal for an engineer who enjoys building, troubleshooting, and operating large-scale test systems and wants to be directly involved in advancing high-Mach technology. Responsibilities:

• Design, develop, and maintain propulsion test stands and associated infrastructure, including mechanical systems, fluid systems, and instrumentation.
• Execute propulsion and subsystem test operations, including planning, integration, checkouts, and post-test analysis.
• Support the maintenance of existing test equipment, data acquisition systems, and control hardware.
• Generate and review detailed test plans, procedures, and safety documentation.
• Collaborate with propulsion, GNC, software, and vehicle systems engineers to support test article integration and operation.
• Analyze test data to validate performance, identify anomalies, and recommend design or procedural improvements.
• Participate in system readiness reviews, safety walkdowns, and test preparation activities.
• Work with technicians to install hardware, route fluid lines, connect instrumentation, and configure control systems.
• Support root-cause investigations and corrective actions when test failures or anomalies occur.
• Drive continuous improvements in test operations, safety, and reliability processes.

Minimum Requirements:

• Bachelors degree in Mechanical, Aerospace, or a related Engineering discipline.
• 7+ years of experience in propulsion test, mechanical systems, or fluid systems design and operation.
• Hands-on experience working with high-pressure, cryogenic, or high-temperature fluid systems.
• Proficiency in reading and creating P&IDs and mechanical drawings
• Experience with data acquisition and control systems.
• Strong understanding of system safety practices and operational discipline in hazardous test environments.
• Excellent analytical, troubleshooting, and problem-solving skills.
• Effective communicator who can work independently within a fast-paced, cross-functional team.
• Valid drivers license and ability to work extended hours or weekends as required by test schedules.
• U.S. citizenship and ability to obtain and maintain a security clearance.

Preferred Skills and Experience

• Masters degree in Aerospace, Mechanical, or related field.
• Experience with air-breathing or rocket propulsion systems (turbomachinery, ramjet, scramjet, or hybrid systems).
• Familiarity with ASME B31.3, ASME BPVC Section VIII, and pressure vessel/facility standards.
• Experience with command and control systems, PLCs, and test automation.
• Background in instrumentation calibration, dynamic data collection, and signal processing.
• Experience with facility commissioning or large-scale test system buildouts.
• Hazardous operations or pyrotechnic system experience.
• Familiarity with DOE, DoD, or NASA test safety and operational standards.

The salary information provided is a general guideline only. Hermeus takes various factors into account, including, but not limited to, the position's scope and responsibilities, the candidate's professional background, education and training, essential skills, and market and business considerations, when presenting a job offer. Salary is only one part of our total compensation and benefits package.Hermeus offers competitive salary and equity, unlimited PTO policy, paid parental leave, potential for year-end bonuses, and more! 100% employer-paid health care 401k & Retirement Plans Unlimited PTO Weekly Paid Office Lunches End of Year Bonuses Fully stocked breakrooms Stock Options Paid Parental Leave U.S. EXPORT CONTROL COMPLIANCE STATUS The person hired will have access to information and items subject to U.S. export controls, and therefore, must either be a U.S. person as defined by22 C.F.R. 120.62or otherwise eligible for deemed export licensing. US persons include U.S. citizens, U.S. nationals, lawful permanent residents (green card holders), and asylees and refugees with such status granted, not pending.
EQUAL OPPORTUNITYHermeus is an Equal Opportunity Employer. Employment decisions at Hermeus are based solely on merit, competence, and qualifications, without regard to race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability, or any other legally protected status.

$138,550 - $187,450 a year