Advanced Reentry Technologies Who We Are: Inversion is an aerospace and defense company pioneering advanced reentry technology to enable next-generation capabilities from space. By combining high-performance materials, precision aerodynamics, and mission-driven autonomy, Inversion is transforming reentry into an operational capability for an entirely new class of missions. The company’s highly maneuverable reentry spacecraft, Arc, is designed for rapid global cargo delivery, hypersonic testing, and other national security missions that require precise, controlled flight through the atmosphere. Arc creates an entirely new transportation domain, unlocking unprecedented speed and global reach. Headquartered in Los Angeles, Inversion designs, manufactures, and integrates its spacecraft under one roof, enabling the company to move rapidly from concept to flight. The company is backed by leading investors including Y Combinator, Spark Capital, and Lockheed Martin Ventures, with customers across the U.S. government and commercial space industry. Position Overview: The aerothermal environments that Inversion's vehicles fly through push beyond what off-the-shelf analysis tools can characterize. As the Staff Aerothermal CFD Methods Engineer, you will build and extend the computational tools our aerothermal team depends on developing new physics models, numeric's, and solver capabilities rather than simply applying existing ones. A meaningful portion of this work will involve developing extensions to US3D. Key Responsibilities: - Build and extend the computational tools used to characterize the aerothermal environment around reentry vehicles. - Develop, implement, and validate extensions to existing high enthalpy flow solvers, spanning physics models, numerical methods, and solver infrastructure. - Implement and improve models of high-temperature gas dynamics, including thermochemical non-equilibrium and finite-rate chemistry including ablation products or other additional species present in flow. - Develop multi-phase flow modeling capability with an emphasis on droplet interactions atomization and breakup, evaporation, droplet-shock and droplet-surface interaction, and two-way coupling between dispersed and continuous phases. - Verify and validate new capabilities against analytical solutions, ground test, and flight data. - Work closely with production aerothermal analysts to harden new capabilities into reliable, documented tools. - Mentor engineers across the aerothermal team. Required Qualifications: - Bachelor's degree in Aerospace or Mechanical Engineering, Applied Mathematics, Physics, or equivalent experience in a related field. - Typically, 9+ years of experience developing CFD methods and solver capabilities. - Experience writing, extending or modifying high-enthalpy CFD solvers. - Experience modeling high-temperature gas dynamics and chemistry, including thermochemical non-equilibrium. - Experience modeling multi-phase flows with an emphasis on droplet interactions — such as spray atomization and breakup modeling for fuel injection systems, or coolant droplet modeling for turbine engines. - Strong fundamentals in numerical methods for compressible flow, including finite volume discretization, shock capturing, and implicit solution methods. - Proficiency in compiled scientific programming languages such as Fortran, C, or C++. - Proven ability to work effectively in a fast-paced environment, including prototyping and rapid iteration of new products. - Must have the ability to obtain and maintain a U.S. government Secret/Top Secret security clearance. Desired Qualifications: - PhD in Aerospace or Mechanical Engineering, Applied Mathematics, or a related field. - Familiarity with both Lagrangian and Eulerian approaches to particle tracking as well as experience with droplet breakup and dispersion models (e.g., KH-RT, TAB). - Experience with Fortran, particularly in the context of extending existing solver codebases. - Direct experience with US3D, including extension through user-defined subroutines. - Experience with plasma simulation for weakly ionized flows and / or experience with electromagnetic simulation. - Experience with parallel scientific computing (e.g., MPI) on large-scale HPC systems. - Prior experience working in startups and/or small independent teams. Our office headquarters is located in Playa Vista, CA. This position requires in-office presence. The California annual base salary for this role is currently $161,000-$221,000. Pay Grades are determined by role, level, location, and alignment with market data. Individual pay will be determined on a case-by-case basis and may vary based on the following considerations: interviews and an assessment of several factors that are unique to each candidate, job-related skills, relevant education and experience, certifications, abilities of the candidate and internal equity. ITAR Compliance: 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. Learn more about the ITAR here . Equal Employment Opportunity: Inversion provides equal employment opportunities to all employees and applicants without regard to race, color, religion, age, sex, gender identity, sexual orientation, national origin, veteran status, or disability. 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