Staff Mechanical Engineer – Thermal

Firestorm•San Diego, CA

12h•$145,000 - $165,000•Onsite

About The Position

At Firestorm, we are building the future of expeditionary defense manufacturing and autonomous systems. Modern conflict has exposed a fundamental problem: the systems needed most by operators are often too expensive, too slow to produce, and too difficult to sustain at scale. Firestorm exists to change that. We develop mission-adaptable aerial systems and deployable manufacturing infrastructure designed to put capability directly into the hands of the warfighter. From modular unmanned aircraft to xCell — our deployable microfactory — our goal is to make defense systems rapidly deployable, adaptable, and producible at the point of need. We are looking for builders, operators, and problem-solvers who want to work on meaningful technology with real-world impact. As a Staff Thermal Engineer at Firestorm, you will own the thermal architecture, analysis, and validation of the systems that keep our sUAS platforms—and the high-power payloads they carry—operating reliably across the full mission envelope. You will design the cooling solutions for engines, batteries, avionics, radios, and electro-optical payloads, balancing thermal performance against the brutal SWaP-C constraints of small unmanned aircraft. This is a hands-on, full-time role with end-to-end ownership: define thermal requirements, build analytical and CFD models, design heat rejection hardware, specify surface treatments and thermal interface materials, and run benchtop and environmental testing through flight qualification. You will be the thermal authority across all air vehicles, working shoulder-to-shoulder with propulsion, electrical, structures, and payloads engineering to make sure nothing on our aircraft ever fails because it got too hot.

Requirements

Bachelor's degree in Mechanical Engineering, Aerospace Engineering, or a related field (Master's degree preferred)
7+ years of experience in thermal engineering, preferably in aerospace, defense, automotive, or high-power electronics
Deep proficiency in CFD and thermal analysis tools (Ansys Icepak, Fluent, Thermal Desktop, Star-CCM+, or equivalent)
Strong fundamentals in heat transfer—conduction, convection, radiation—and ability to validate models by hand
Hands-on experience designing forced-air and conduction cooling solutions for embedded electronics and/or propulsion systems
Experience designing, modeling, or validating oscillating or copper/water heat pipe systems for highpower electronics or aerospace applications
Experience selecting and qualifying thermal interface materials, coatings, and surface treatments
Demonstrated history of running thermal test campaigns: instrumentation, environmental chambers, IR thermography, and model correlation
Familiarity with environmental qualification standards such as MIL-STD-810 and DO-160
Proficiency in Python or MATLAB for thermal data reduction and analysis
Excellent problem-solving skills and attention to detail
Strong communication and teamwork skills
Ability to work in a fast-paced and dynamic startup environment
U.S. Citizenship and ability to obtain and maintain a U.S. Government security clearance

Nice To Haves

Experience with small piston engine thermal management (heavy fuel or gasoline)
Experience with lithium-ion battery thermal design and runaway mitigation
Experience with EO/IR, EW, or other heat-dense payload integration
Background in UAS, Aircraft, missile, or other SWaP-constrained airborne platforms

Responsibilities

Develop thermal architectures for sUAS platforms covering engines, fuel systems, batteries, ESCs, flight computers, radios, EO/IR payloads, and other mission electronics.
Build and run thermal analyses—from first-principles hand calculations to detailed CFD and FEA (Ansys Icepak, Fluent, Thermal Desktop, or equivalent)—to predict component and system-level performance.
Design active and passive cooling solutions, including forced-air ducting, cold plates, heat sinks, heat pipes, and conduction paths into airframe structure.
Select and specify thermal interface materials, gap pads, potting compounds, and surface treatments; perform α/ε trade studies for radiative surfaces and anodized enclosures.
Own the thermal qualification campaign: define thermal test plans, instrument prototypes with thermocouples and IR imaging, run environmental chamber testing, and correlate models to data.
Partner with electrical engineering on PCB thermal design, component derating, and enclosure heat rejection.
Support payload integration by characterizing thermal performance of EO/IR sensors, RF emitters, and other heat-dense modules at altitude and in hot/cold soak conditions.
Generate and maintain thermal engineering documentation: analysis reports, test plans, qualification reports, and thermal budgets tracked at the system level.
Travel to test sites and customer flight events to instrument aircraft, capture thermal flight data, and validate models in operational conditions.

Benefits

Relocation assistance is available
Comprehensive medical, dental, and vision plans
401(k) Retirement Savings Plan
Equity grants for new hires
Unlimited PTO
Extremely generous company holiday calendar, including a holiday hiatus in November & December
Generous Parental Leave
Lifestyle Spending Account
FSA
DCFSA
HSA
Hospital Indemnity insurance
Critical Illness insurance
Accident insurance
Basic Life/AD&D, short-term and long-term disability insurance, 100% covered by Firestorm. Plus, the option to purchase additional life insurance for you and your family.
Mental Health Resources: We provide free mental health resources 24/7 including therapy and more. Additional work-life services, such as free legal and financial support, are available to you as well.