Propulsion Engineer II/III - Alpha Engines

Firefly Aerospace, Inc.; Texas; On-site; USD 100,000 - 150,000; Full time

Benefits offered by this job

Health benefits

Relocation assistance

Educational reimbursement

Flexible PTO

Job summary

Firefly Aerospace, Inc. is seeking a Propulsion Engineer II/III for the Alpha Engines team in north Austin, TX. You will own engine hardware across its lifecycle, leading design, analysis, testing, and collaboration with cross-functional teams to ensure successful launches.

The role requires deep technical knowledge, ownership mindset, and ability to communicate with propulsion, structures, avionics, and vehicle systems in a fast-paced environment.

Qualifications

• B.S. in Mechanical, Aerospace, or related engineering field.
• Level II: 3+ years of propulsion system experience. Level III: 7+ years.
• Strong fundamentals inFluid dynamics, thermodynamics, heat transfer, and solid mechanics.
• Proven hardware ownership across product lifecycle and strong problem-solving skills.
• Hands-on hardware design, fabrication, and testing; CAD and CM tools familiarity.

Responsibilities

• Own engine hardware through the full lifecycle from concept to flight.
• Lead design and analysis of engine components to meet performance and reliability.
• Drive fluid, structural, thermal, and dynamic analyses.
• Collaborate with manufacturing and integration teams to develop processes and test procedures.
• Plan, coordinate, and execute development, qualification, and acceptance testing of flight hardware.

Skills

Fluid dynamics

Thermodynamics

Heat transfer

Solid mechanics

Engineering fundamentals

Problem solving

Communication

Technical writing

Hardware ownership

Python MATLAB LabVIEW

Education

B.S. in Mechanical/Aerospace engineering

Tools

Siemens NX

Teamcenter

Job description

At Firefly, we’re focused on making space attainable for everyone – including you! Each team member’s passion, dedication, and innovative ideas have a direct impact on fueling our successful trajectory into space. And there’s no shortage of meaningful projects to work on at Firefly. With launch, lunar, and orbital vehicles, Firefly has a diverse line of business with opportunities to get hands‑on experience launching rockets, operating in space, and landing on the Moon.

Our missions are powered by our incredible team ...

Our missions are powered by our incredible team ...

Our Values

Headquartered in the Lone Star State, Firefly’s hardworking team reflects Texas’ GO BIG culture in everything we do. We build big, achieve big, and dream big. We’re building launch vehicles and spacecraft to provide rapid, reliable space access. We’ve achieved some incredible wins, including the first successful commercial Moon landing. And we’re dreaming bigger than this planet with ambitions to Mars, Venus, and beyond. Our core values are what drive us along the way.

Passion

Fireflies believe in perseverance, responsiveness, and mentoring others with a focus on inspiring a better future.

Accountability

Fireflies act with integrity and take ownership of our actions, commitments, decisions, and outcomes.

Fireflies work in alignment across teams and communicate clearly with mutual respect for one another.

Fireflies deliver high-quality work through technical rigor and timely disciplined execution for our customers.

We take care of our Fireflies with some of the best benefits in the industry. Our mission to make space for everyone starts with our employees and allowing them to make space for their family, their career, and their future.

Space for You

• Unlimited PTO for exempt employees
• 3-month sabbatical for every 5 years of service
• Medical, dental, vision, life, and disability insurance
• Mental health services
• Paid military leave

Space for Your Family

• 12 weeks paid maternity leave
• 4 weeks paid spouse leave
• $20k towards family planning: fertility, surrogacy, adoption
• Dog friendly workplace

Space for Your Career

• $10k/year towards trade school or college
• Ongoing coaching to advance leadership skills
• • Employee‑ownership with stock bonuses
  • 4% Safe Harbor 401(k) matching
  • $10k bonus for home purchase in Cedar Park, Texas

Job Openings

From launch technicians to propulsion engineers, Firefly has open roles across the company. We’re looking for passionate, bright innovators to join our team and help make space an achievable dream for everyone.

Propulsion Engineer II/III - Alpha Engines

Firefly Aerospace is a space and defense technology company that enables our world to launch, land, and operate in space – anywhere, anytime. As the partner of choice for critical space missions, Firefly is the only commercial company to launch a satellite to orbit with 24-hour notice and the only company to achieve a successful Moon landing. Our launch vehicles, lunar landers, and orbital vehicles provide government and commercial customers with full mission services from low Earth orbit to the Moon and beyond. Headquartered in north Austin, Texas, Firefly is looking for passionate, hardworking innovators to join our team and help fuel our successful trajectory into space.

About the Role

The Alpha Engines team is responsible for the design, integration, and operation of the Reaver and Lightning engines that power the first and second stages of Firefly’s Alpha launch vehicle.

As a Responsible Engineer, you will own engine hardware across its full lifecycle – requirements definition, design, analysis, development, test, qualification, and flight. You will lead the design and analysis of the hardware, collaborate with fabrication and integration teams to manufacture and assemble the system, and support vehicle testing and launch operations. You will serve as a subject matter expert for the Alpha Engines team and provide an active voice in engine development, test campaigns, and launch operations.

This role requires deep technical knowledge, extreme ownership of hardware from concept to flight, and clear communication with cross-functional partners including propulsion, structures, avionics, and vehicle systems. The successful candidate will be a self-starter who enjoys challenging assumptions, thrives in a fast-paced development environment, and seeks to make impactful contributions to Firefly’s mission.

Responsibilities

• Demonstrate full ownership of launch vehicle engine hardware through the full product life cycle
• Lead the design and analysis of engine components and assemblies to meet performance, reliability, manufacturability, and operability requirements
• Drive component and system analyses including fluid, structural, thermal, and dynamic
• Collaborate with manufacturing and integration teams to develop processes, work instructions, and test procedures
• Plan, coordinate, and execute development, qualification, and acceptance testing of flight hardware, including data analysis and reviews
• Develop tools for design, analysis, and test data review
• Author and present design review, test readiness, launch readiness, and data review presentations to internal and external stakeholders
• Identify system-level risks, perform trade studies, and drive decisions based on technical merit, risk, cost, schedule, and quality to ensure successful engine and vehicle operation
• Serve as the propulsion representative for your hardware during engine testing, stage testing, and launch operations

Qualifications

Required

• B.S. in Mechanical, Aerospace, or a related engineering discipline
• Level II: 3+ years of experience developing launch vehicle propulsion systems. Level III: 7+ years of experience developing launch vehicle propulsion systems.
• Strong understanding of engineering fundamentals especially fluid dynamics, thermodynamics, heat transfer, and solid mechanics
• Demonstrated history of applying engineering first principles to arrive at simple, robust solutions
• Proven experience with strong hardware ownership through multiple aspects of the product lifecycle
• Hands‑on experience with hardware design, fabrication, and testing
• Experience with CAD and configuration management tools (Siemens NX and Teamcenter preferred), and comprehension of GD&T, tolerancing, and ASME Y14.5
• Familiarity with Python, MATLAB, LabVIEW, GFSSP, or other control, data acquisition, and reduction software
• Working knowledge of manufacturing, fabrication, integration, and quality control relevant to fluid components
• Excellent problem-solving, communication, and technical writing skills
• Proven ability to rapidly develop solutions with partially defined or evolving requirements

Desired Qualifications

• Advanced degree in Mechanical Engineering, Aerospace Engineering, or an equivalent field
• 5+ years of experience developing launch vehicle propulsion systems
• Demonstrated experience of full hardware lifecycle ownership, from blank-sheet design through full operation
• Strong understanding in engineering fundamentals of propulsion systems and combustion devices
• In‑depth knowledge of cryogenic, high‑pressure, or high‑temperature system operations and compatible material selection
• Experience with fluid system subcomponent or pressurized component development, design, or testing
• Experience testing or operating complex engineering systems
• Experience with data acquisition systems and test instrumentation including pressure transducers, thermocouples, RTDs, flow meters, load cells, and accelerometers
• Experience optimizing design of hardware for improvements in reliability, manufacturability, performance, cost, and simplicity

Firefly offers outstanding benefits for our employees, including generous health, dental and vision plans with low plan deductibles, parental leave, relocation benefits, educational reimbursement, short term disability, and flexible PTO options.

To conform to U.S. Government space technology export regulations, including the International Traffic in Arms Regulations (ITAR) you must be a U.S. citizen, lawful permanent resident of the U.S., protected individual as defined by 8 U.S.C. 1324b(a)(3), or eligible to obtain the required authorizations from the U.S. Department of State.

Firefly Aerospace, Inc. is an Equal Opportunity Employer; employment with Firefly is governed based on merit, competence and qualifications and will not be influenced in any manner by 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.