Fluids Engineer III

Firefly Aerospace, Inc.; Austin, Northern (TX, KY); Hybrid; USD 90,000 - 140,000; Full time

Benefits offered by this job

Health insurance

Dental & Vision coverage

Parental leave

Education reimbursement

Short-term disability

Flexible PTO

Job summary

Firefly Aerospace, Inc. seeks an FGSE Engineer to own end-to-end fluid systems for launch sites, test stands, and production facilities. You’ll design, analyze, and build complex fluid systems and work with technicians to resolve real-world challenges across Alpha, Eclipse, and other programs.

You’ll also mentor early-career engineers, lead design reviews, and travel up to 30% to support builds and activations, contributing to Firefly’s mission of reliable space access.

Qualifications

• Bachelor’s degree in mechanical or aerospace engineering.
• 5–10 years of fluid systems experience in design, test, or operations.
• Thorough understanding of fluid dynamics and thermodynamics.
• Experience with valves, regulators, tubing, and instrumentation.
• Experience creating P&IDs and fluid system sizing.
• Proficient with 3D CAD and NX.
• Ability to travel up to 30%.
• Experience in aerospace, R&D, or oil & gas environment.
• Familiarity with ASME, NASA, and AFSPCMAN standards.
• Hands-on construction, troubleshooting, and operation of fluid systems.

Responsibilities

• Design, analyze, and build test stand and launch pad fluid systems.
• Create schematics, P&IDs, BOMs, CAD drawings.
• Collaborate with technicians and welders to implement designs.
• Lead internal and external design reviews.
• Mentor junior engineers and improve engineering tools.
• Travel to test sites to support build and activation.

Skills

Fluid systems

P&IDs

Thermodynamics

Fluid dynamics

3D CAD

GSE experience

Education

Bachelor’s degree in mechanical or aerospace engineering

Advanced degree (preferred)

Tools

Siemens NX

REFPROP

GFSSP

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.

The engine powering Alpha`s first stage is truly ...

The engine powering Alpha`s first stage is truly ...

760 4

More cleanroom space. More spacecraft in ...

More cleanroom space. More spacecraft in ...

Twenty‑five years later, we remember the lives ...

Twenty‑five years later, we remember the lives ...

354 1

In this Manufacturing Minute, our Tooling ...

In this Manufacturing Minute, our Tooling ...

317 9

As we head into the holiday weekend, we’re proud ...

As we head into the holiday weekend, we’re proud ...

1079 4

What does it take to make a lander space‑ready? ...

What does it take to make a lander space‑ready? ...

532 8

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.

Firefly Aerospace is a space and defense technology company on a mission to reliably and repeatedly launch, land, and operate space systems from Earth to the Moon and beyond. As the partner of choice for critical space missions, Firefly is the first commercial company to launch a satellite to orbit with 24-hour notice and the first company to achieve a successful Moon landing. Headquartered in north Austin, Texas, Firefly is looking for passionate, hardworking innovators to join our team and help fuel our successful trajectory into space.

SUMMARY

As a Fluids Ground Support Equipment (FGSE) Engineer at Firefly, you'll own the complete lifecycle of critical fluid systems at our launch sites, test stands, and production facilities. You'll work in a dynamic and collaborative environment designing and building large complex fluid systems, including incompressible, cryogenics, propellants, and high‑pressure gas systems. You’ll be solving real‑world problems in real‑time alongside skilled technicians, welders, and cross‑functional teams. From architecture trades and detailed designs through fabrication, installation, and activation, you'll be the technical decision‑maker ensuring Firefly's launch sites and test stands meet the current and future needs for each of Firefly’s programs.

This role offers exposure across Firefly's entire fleet - Alpha, Eclipse, Elytra, and Blue Ghost - giving you an unparalleled breadth of experiences and challenges as you help define the next generation of test and launch infrastructure.

RESPONSIBILITIES

• Design, analyze, and build test stand and launch pad fluid systems, including incompressible, cryogenic, and high‑pressure gas systems
• Own the full design cycle of your fluid systems, including generating schematics and P&IDs, sizing components, generating BOMs, creating CAD, procuring hardware, and generating drawings
• Work directly with technicians and welders to schedule, prepare, and build your designs and fix real‑world problems
• Participate in and lead internal design reviews, operational readiness reviews, and represent Firefly during external design reviews
• Mentor early career engineers on the team and further develop engineering tools and processes
• Travel to test and launch sites, as required, to support build and commissioning of new and upgraded fluid system

QUALIFICATIONS

Required

• Bachelor’s degree in mechanical engineering, aerospace engineering, or equivalent
• 5-10 years of recent experience in a professional setting outside the classroom with fluid systems, pneumatics, hydraulics, or HVAC systems in a design, assembly, test, or operations capacity
• Thorough understanding of fluid dynamics and thermodynamics
• Solid understanding of fluid components such as valves, regulators, pressure transducers, tubing, tanks, pressurized hardware, seals, and instrumentation
• Experience with fluid system subcomponent or pressurized component development, design, or testing (such as valves, regulators, piping systems, pumps, etc..)
• Working knowledge of manufacturing, fabrication, integration & quality control relevant to fluid components (such as machining, inspection, welding, assembly, testing, etc.)
• Demonstrated ability to do clean sheet designs of pressurization systems, propellant systems, or other complex multidisciplinary systems
• Experience creating P&IDs, performing fluid system sizing, fluid component and instrumentation selection, and pressurized system design
• Experience using fluids analysis tools such as REFPROP, GFSSP or other computer‑based fluid dynamic modeling
• Proficient with 3D & 2D CAD software packages such as Siemens NX
• Capable of balancing detailed design tasks with higher level project management style tasks, including budgeting, scheduling, and communications
• Able to travel in support of GSE build and activation up to 30% of the time
• Advanced degree in mechanical, aerospace, or equivalent field
• Direct hands‑on experience building, troubleshooting, and/or operating complex fluid or mechanical systems
• Cryogenic system design and/or operational experience
• Hypergolic system design and/or operational experience
• Experience working in an aerospace, R&D, or oil & gas environment.
• Familiarity with ASME, NASA, and AFSPCMAN standards related to fluid system design, such as ASME B31.3, ASME BPVC Section VIII, and/or AFSPCMAN 91-710
• Direct experience with design and build of ground systems (GSE) or related fluid systems including, but not limited to test environments, fluid or gas conditioning/storage, manufacturing processes, and compressible gases

Firefly offers outstanding benefits for our employees, including generous health, dental and vision plans with low plan deductibles, parental leave, 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.