Senior Thermal Systems Design Engineer

About the role

Astro-mechanica is advancing high-speed flight capabilities through the development of the Duality propulsion system, targeting a transformation in global transportation and support for government aerospace programs. The organization seeks a thermal systems specialist to assume ownership of the design, prototyping, and flight qualification lifecycle for thermal management hardware. This position operates inside a flat, high-velocity engineering culture where first-principles reasoning and individual accountability serve as the main catalysts for technical advancement. The successful candidate will bridge analytical prediction with physical hardware reality, ensuring thermal architectures survive the extreme environments inherent to advanced propulsion.

Key facts

What you'll do

• Generate parametric CAD models and fully dimensioned technical drawings adhering to rigorous Geometric Dimensioning and Tolerancing (GD&T) standards using Siemens NX.
• Architect comprehensive thermal management systems and construct one-dimensional fluid network models to predict steady-state performance and transient thermal behavior across mission profiles.
• Perform sizing calculations and component selection for critical fluid hardware, including pumps, control valves, heat exchangers, and pressure regulators, ensuring compatibility with system pressure drops and flow requirements.
• Execute Computational Fluid Dynamics (CFD) simulations and analytical hand calculations to optimize internal flow paths, heat transfer coefficients, and overall system efficiency.
• Map thermal energy dissipation and conduction pathways throughout the propulsion assembly while defining instrumentation strategies - thermocouples, pressure transducers, flow meters - to enable rigorous correlation of analytical models against empirical test data.
• Lead formal internal design reviews, presenting technical rationale, risk assessments, and verification plans to cross-functional stakeholders.
• Fabricate prototype hardware, develop detailed test procedures and acceptance criteria, and conduct post-test data reduction to characterize thermal performance margins.
• Diagnose thermal anomalies and performance shortfalls through rapid design-test-fix iteration cycles, implementing corrective actions on compressed timelines.
• Collaborate closely with structures, avionics, and propulsion leads to integrate thermal hardware within tight volumetric and mass constraints.
• Define and maintain thermal verification and validation (V&V) documentation required for flight qualification and government program compliance.
• Support hot-fire test campaigns by providing real-time thermal monitoring support and post-test forensic analysis of hardware condition.
• Contribute to the development of internal thermal analysis standards, modeling best practices, and lessons-learned databases.

Requirements

• Minimum five years of professional experience designing thermal-fluid systems for rocket propulsion, hypersonic vehicles, or similarly high-complexity, high-heat-flux aerospace applications.
• Expert-level proficiency in Siemens NX for solid modeling, assembly management, and production drawing creation.
• Mastery of fundamental fluid dynamics, thermodynamics, and heat transfer principles, with demonstrated ability to apply first-principles analysis to novel configurations.
• Hands-on experience with industry-standard CFD solvers (e.g., ANSYS Fluent, STAR-CCM+, CONVERGE) and 1-D thermal-fluid network modeling tools (e.g., Thermal Desktop, FloCAD, SINDA/FLUINT, Modelica).
• Proven track record specifying instrumentation suites, executing test campaigns, and correlating analytical predictions with physical test results to close model uncertainty gaps.
• Demonstrated ability to operate autonomously with a proactive, continuous-improvement mindset, delivering high-fidelity engineering output without micromanagement.
• Capacity to thrive in a rapidly evolving, high-velocity startup environment where requirements shift frequently and bureaucracy is minimal.
• U.S. Person status (Citizen or Permanent Resident) required due to ITAR/EAR export control regulations governing propulsion technology.

Nice to have

• Direct experience with regenerative cooling channel design, film cooling optimization, or transpiration cooling for liquid rocket engines.
• Familiarity with high-pressure oxygen compatibility standards, materials selection (e.g., Inconel, copper alloys, CRES), and cleanliness protocols (ASTM G93).
• Background in additive manufacturing (DMLS/SLM) process development for thermal hardware, including parameter optimization for thermal conductivity and surface roughness.
• Experience with cryogenic fluid management systems, including chilldown modeling and two-phase flow dynamics.
• Proficiency in scripting languages (Python, MATLAB) for automation of pre/post-processing workflows and design optimization loops.
• Prior involvement in flight hardware qualification programs (DO-160, MIL-STD-810, or NASA-STD-5017) or government launch vehicle certification processes.

Skills & tools

• Siemens NX (CAD, Drafting, CAE integration)
• Geometric Dimensioning & Tolerancing (ASME Y14.5)
• Computational Fluid Dynamics (CFD): ANSYS Fluent, STAR-CCM+, or equivalent
• 1-D Thermal-Fluid Network Modeling: Thermal Desktop/FloCAD, SINDA/FLUINT, Modelica/Dymola
• Thermodynamics & Heat Transfer (Conduction, Convection, Radiation, Phase Change)
• Fluid Systems Design & Component Sizing (Pumps, Valves, Heat Exchangers, Regulators)
• Propulsion Thermal Management (Regenerative Cooling, Ablative, Radiative)
• Instrumentation & Data Acquisition (Thermocouples, RTDs, Pressure Transducers, High-Speed DAQ)
• Test Planning, Execution & Model Correlation
• Python / MATLAB for Engineering Automation
• Version Control (Git) & PLM Systems
• Export Control Compliance (ITAR/EAR)

Practical notes

This position mandates on-site presence at the San Francisco facility five days per week; remote or hybrid arrangements are not available for this role. The comprehensive benefits package includes medical, dental, and vision insurance coverage, Flexible Spending Account (FSA) options, a 401(k) retirement plan, equity compensation via stock options, and a flexible time-off policy encompassing vacation, sick leave, and company holidays. Astro-mechanica operates as an equal opportunity employer committed to workforce diversity. Candidates must be legally authorized to work in the United States without sponsorship, as the company does not currently support visa applications (H-1B, O-1, TN, or similar) for this position.

META

Company: Astro Mechanica

Title: Senior Thermal Systems Design Engineer

Listed

location: San Francisco

Job type: full_time